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Huang M, Zhang M, Chang J, Le C, Zanzonico P, Humm J, Koutcher J, Ling C. TU-D-332-01: Mapping of Viable Tumor Regions Using Gd-DTPA DCE-MRI. Med Phys 2008. [DOI: 10.1118/1.2962592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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77
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Zhang M, Li X, Suehiro M, Zhao Z, Gagne D, Pizzonia J, Li G, Ling C, Humm J. TU-C-332-09: Effects of Mild Temperature Hyperthermia On Rat HT29 Xenograft Hypoxia Measured with a Dual-Radiolabel Hypoxia Marker. Med Phys 2008. [DOI: 10.1118/1.2962531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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78
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Ling C, Del Guerra S, Lupi R, Rönn T, Granhall C, Luthman H, Masiello P, Marchetti P, Groop L, Del Prato S. Epigenetic regulation of PPARGC1A in human type 2 diabetic islets and effect on insulin secretion. Diabetologia 2008; 51:615-22. [PMID: 18270681 PMCID: PMC2270364 DOI: 10.1007/s00125-007-0916-5] [Citation(s) in RCA: 317] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Accepted: 12/10/2007] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS Insulin secretion in pancreatic islets is dependent upon mitochondrial function and production of ATP. The transcriptional coactivator peroxisome proliferator activated receptor gamma coactivator-1 alpha (protein PGC-1alpha; gene PPARGC1A) is a master regulator of mitochondrial genes and its expression is decreased and related to impaired oxidative phosphorylation in muscle from patients with type 2 diabetes. Whether it plays a similar role in human pancreatic islets is not known. We therefore investigated if PPARGC1A expression is altered in islets from patients with type 2 diabetes and whether this expression is influenced by genetic (PPARGC1A Gly482Ser polymorphism) and epigenetic (DNA methylation) factors. We also tested if experimental downregulation of PPARGC1A expression in human islets influenced insulin secretion. METHODS The PPARGC1A Gly482Ser polymorphism was genotyped in human pancreatic islets from 48 non-diabetic and 12 type 2 diabetic multi-organ donors and related to PPARGC1A mRNA expression. DNA methylation of the PPARGC1A promoter was analysed in pancreatic islets from ten type 2 diabetic and nine control donors. Isolated human islets were transfected with PPARGC1A silencing RNA (siRNA). RESULTS PPARGC1A mRNA expression was reduced by 90% (p<0.005) and correlated with the reduction in insulin secretion in islets from patients with type 2 diabetes. After downregulation of PPARGC1A expression in human islets by siRNA, insulin secretion was reduced by 41% (p <or= 0. 01). We were able to ascribe reduced PPARGC1A expression in islets to both genetic and epigenetic factors, i.e. a common PPARGC1A Gly482Ser polymorphism was associated with reduced PPARGC1A mRNA expression (p<0.00005) and reduced insulin secretion (p<0.05). In support of an epigenetic influence, the PPARGC1A gene promoter showed a twofold increase in DNA methylation in diabetic islets compared with non-diabetic islets (p<0.04). CONCLUSIONS/INTERPRETATION We have shown for the first time that PPARGC1A might be important in human islet insulin secretion and that expression of PPARGC1A in human islets can be regulated by both genetic and epigenetic factors.
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Ling C, Connor KA, Demers DR, Radke RJ, Schoch PM. Computer simulation of three-dimensional heavy ion beam trajectory imaging techniques used for magnetic field estimation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2007; 78:113505. [PMID: 18052472 DOI: 10.1063/1.2804108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A magnetic field mapping technique via heavy ion beam trajectory imaging is being developed on the Madison Symmetric Torus reversed field pinch. This paper describes the computational tools created to model camera images of the light emitted from a simulated ion beam, reconstruct a three-dimensional trajectory, and estimate the accuracy of the reconstruction. First, a computer model is used to create images of the torus interior from any candidate camera location. It is used to explore the visual field of the camera and thus to guide camera parameters and placement. Second, it is shown that a three-dimensional ion beam trajectory can be recovered from a pair of perspectively projected trajectory images. The reconstruction considers effects due to finite beam size, nonuniform beam current density, and image background noise. Third, it is demonstrated that the trajectory reconstructed from camera images can help compute magnetic field profiles, and might be used as an additional constraint to an equilibrium reconstruction code, such as MSTFit.
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Ling C, Wegner L, Andersen G, Almgren P, Hansen T, Pedersen O, Groop L, Vaag A, Poulsen P. Impact of the peroxisome proliferator activated receptor-gamma coactivator-1beta (PGC-1beta) Ala203Pro polymorphism on in vivo metabolism, PGC-1beta expression and fibre type composition in human skeletal muscle. Diabetologia 2007; 50:1615-20. [PMID: 17579828 DOI: 10.1007/s00125-007-0729-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Accepted: 04/30/2007] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Peroxisome proliferator activated receptor-gamma coactivator-1beta (PGC-1beta, also known as PPARGC1B) expression is reduced in skeletal muscle from patients with type 2 diabetes mellitus and in elderly subjects. Ala203Pro, a common variant in the PGC-1beta gene is associated with obesity. The aim of this study was to investigate whether the PGC-1beta Ala203Pro polymorphism influences the age-related decline in skeletal muscle PGC-1beta expression, in vivo metabolism and markers for muscle fibre type composition. MATERIALS AND METHODS The PGC-1beta Ala203Pro polymorphism was genotyped in 110 young (age 28.0 +/- 1.9 years) and 86 elderly (age 62.4 +/- 2.0 years) twins and related to muscle PGC-1beta expression, in vivo metabolism and markers for fibre type composition. RESULTS Insulin-stimulated non-oxidative glucose metabolism (NOGM; p = 0.025) and glycolytic flux rate (GF; p = 0.026) were reduced in young Ala/Ala carriers compared with carriers of a 203Pro allele. In addition, a regression analysis, correcting for covariates, showed that the PGC-1beta 203Pro allele was positively related to insulin-stimulated NOGM and GF in the young twins. While muscle expression of PGC-1beta was reduced in elderly compared with young carriers of the Ala/Ala genotype (p < or = 0.001), there was no significant age-related decline in PGC-1beta expression in carriers of the 203Pro allele (p > or = 0.4). However, a regression analysis, correcting for covariates, showed that only age was significantly related to muscle PGC-1beta expression. Finally, PGC-1beta expression correlated positively with markers for oxidative fibres in human muscle. CONCLUSIONS/INTERPRETATION This study suggests that young carriers of a PGC-1beta 203Pro allele have enhanced insulin-stimulated glucose metabolism and may be protected against an age-related decline in PGC-1beta expression in muscle.
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Zhang Q, Kriminski S, Ling C, Rosenzweig K, Mageras G. SU-FF-J-49: Reducting of Motion Artifacts in Cone Beam CT Using a Patient Specific Respiratory Motion Model. Med Phys 2007. [DOI: 10.1118/1.2760554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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82
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Zhang M, Chen Q, Li X, O'Donoghue J, Ruan S, Zanzonico P, Ling C, Humm J. SU-FF-I-109: Image Deconvolution in Autoradiography: A Preliminary Study. Med Phys 2007. [DOI: 10.1118/1.2760486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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83
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Fex M, Nitert MD, Wierup N, Sundler F, Ling C, Mulder H. Enhanced mitochondrial metabolism may account for the adaptation to insulin resistance in islets from C57BL/6J mice fed a high-fat diet. Diabetologia 2007; 50:74-83. [PMID: 17093947 DOI: 10.1007/s00125-006-0464-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2006] [Accepted: 08/09/2006] [Indexed: 10/23/2022]
Abstract
AIM/HYPOTHESIS Hyperinsulinaemia maintains euglycaemia in insulin-resistant states. The precise cellular mechanisms by which the beta cells adapt are still unresolved. A peripherally derived cue, such as increased circulating fatty acids, may instruct the beta cell to initiate an adaptive programme to maintain glucose homeostasis. When this fails, type 2 diabetes ensues. Because mitochondria play a key role in beta cell pathophysiology, we tested the hypothesis that mitochondrial metabolism is critical for beta cell adaptation to insulin resistance. METHODS C57BL/6J mice were given high-fat (HF) diet for 12 weeks. We then analysed islet hormone secretion, metabolism in vivo and in vitro, and beta cell morphology. RESULTS HF diet resulted in insulin resistance and glucose intolerance but not frank diabetes. Basal insulin secretion was elevated in isolated islets from HF mice with almost no additional response provoked by high glucose. In contrast, a strong secretory response was seen when islets from HF mice were stimulated with fuels that require mitochondrial metabolism, such as glutamate, glutamine, alpha-ketoisocaproic acid and succinate. Moreover, while glucose oxidation was impaired in islets from HF mice, oxidation of glutamine and palmitate was enhanced. Ultrastructural analysis of islets in HF mice revealed an accumulation of lipid droplets in beta cells and a twofold increase in mitochondrial area. CONCLUSIONS/INTERPRETATION We propose that beta cells exposed to increased lipid flux in insulin resistance respond by increasing mitochondrial volume. This expansion is associated with enhanced mitochondrial metabolism as a means of beta cell compensation.
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He F, Huang Y, Wen B, Deng X, Zanzonico P, Chen Q, Finn R, Ling C, Li G. 2630. Int J Radiat Oncol Biol Phys 2006. [DOI: 10.1016/j.ijrobp.2006.07.1044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wardrop J, Law D, Qiu Y, Engh K, Faitsch L, Ling C. Influence of Solid Phase and Formulation Processing on Stability of Abbott-232 Tablet Formulations. J Pharm Sci 2006; 95:2380-92. [PMID: 16892210 DOI: 10.1002/jps.20679] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abbott-232 is a chemically stable, highly water soluble non-hygroscopic compound selected for development as a potent uroselective alpha(1A) agonist. An anhydrate, a monohydrate, and an amorphous phase were isolated. The anhydrate was chosen for formulation development based on solid-state characterization. Excipients for immediate release (IR) tablet formulations were selected according to compatibility studies. However, the prototype IR tablets designed for clinical trials were found to be chemically unstable. Thus, process-induced phase transformation was investigated as the likely cause of the observed instability. Since the drug loading in the formulations was low (1%), model granulations containing 30% drug were evaluated to test this hypothesis. Investigation using a variety of analytical techniques indicated that the observed degradation was, indeed, a result of a solution-mediated phase transformation from anhydrate to amorphous Abbott-232 during wet granulation. A new direct compression formulation was, therefore, developed to prevent the solution-mediated process induced phase transition. Since the drug loading was low, a polarized light microscope (PLM) method was used to evaluate the solid phase in the new formulation. PLM confirmed that the original anhydrate form remained unchanged in tablets manufactured by the dry process. Stability studies confirmed that both IR and extended release (ER) tablets of Abbott-232 were successfully developed for clinical trials using direct compression.
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Kriminski S, Lovelock D, Mageras G, Yorke E, Rosenzweig K, Mostafavi H, Ling C, Amols H. SU-DD-A3-05: Evaluation of Respiration-Correlated Digital Tomosynthesis for Soft Tissue Visualization. Med Phys 2006. [DOI: 10.1118/1.2240147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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87
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Lovelock D, LoSasso T, Ali I, Amols H, Ling C, Yamada Y, Pham H, Munro P. SU-FF-I-18: Quantifying the Geometric Accuracy of the On Board Imager Over a One-Year Period. Med Phys 2006. [DOI: 10.1118/1.2240256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Fullerton G, Bourland J, Pelizzari C, Ling C, Jaffray D, Eckelman W, Patt B, Hendee W, Mulvaney J, Mackie T, Fenster A, Nagy P, McNitt-Gray M, Chan H. TH-E-330D-01: BIROW - Biomedical Imaging Research Opportunities Workshop: Intersociety Project to Accelerate Biomedical Imaging Discovery and Application - Part II. Med Phys 2006. [DOI: 10.1118/1.2241940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Pugachev A, Carlin S, Ling C, Humm J. SU-FF-J-89: Intratumoral Pattern of FDG Uptake in Human Xenograft Models. Med Phys 2006. [DOI: 10.1118/1.2240865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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90
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Fullerton G, Bourland J, Pelizzari C, Ling C, Jaffray D, Eckelman W, Patt B, Hendee W, Mulvaney J, Mackie T, Fenster A, Nagy P, McNitt-Gray M, Chan H. TH-D-330D-01: BIROW - Biomedical Imaging Research Opportunities Workshop: Intersociety Project to Accelerate Biomedical Imaging Discovery and Application. Med Phys 2006. [DOI: 10.1118/1.2241901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Pevsner A, Erdi Y, Nemeh S, Davis B, Joshi S, Yorke E, Rosenzweig K, Humm J, Larson S, Ling C, Mageras G. SU-FF-I-95: The Use of Deformable Registration Model to Improve Visibility of the Lesion in Gated PET Images. Med Phys 2006. [DOI: 10.1118/1.2240775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Chang J, Wen B, Kazanzides P, Zanzonico P, Finn R, Ling C. WE-D-330A-03: PO2 Measurements in Animal Tumors Using An Image-Guided Robotic System. Med Phys 2006. [DOI: 10.1118/1.2241741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Pitcher DG, Windsor D, Windsor H, Bradbury JM, Yavari C, Jensen JS, Ling C, Webster D. Mycoplasma amphoriforme sp. nov., isolated from a patient with chronic bronchopneumonia. Int J Syst Evol Microbiol 2006; 55:2589-2594. [PMID: 16280532 DOI: 10.1099/ijs.0.63269-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A mycoplasma was isolated from the sputum of an immunodeficient patient with recurrent bronchitis. The isolate designated strain A39T was very fastidious and atypical for a mycoplasma in its colonial appearance. Classical biochemical tests for mycoplasma speciation could not differentiate the isolate from the pathogens Mycoplasma pneumoniae and Mycoplasma genitalium and serological identification as a recognized Mycoplasma species was lacking. Specific PCR detection for these two species was negative. Subsequently, other strains were isolated from human patients that appeared to be similar to strain A39T in their physiological and genetic characteristics. Analysis of the 16S rRNA gene placed strain A39T and other isolates in the pneumoniae group of mycoplasmas, with the highest sequence similarity to Mycoplasma testudinis (96.8 %), but with only 93.0 % similarity to M. pneumoniae and M. genitalium. Examination of the 16S-23S rRNA internally transcribed spacer sequence, protein electrophoresis profile, genome size and serological reactions indicated that this organism represents a novel species, for which the name Mycoplasma amphoriforme sp. nov. is proposed, with strain A39T (=NCTC 11740T=ATCC BAA-992T) as the type strain.
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Creer DD, Dilworth JP, Gillespie SH, Johnston AR, Johnston SL, Ling C, Patel S, Sanderson G, Wallace PG, McHugh TD. Aetiological role of viral and bacterial infections in acute adult lower respiratory tract infection (LRTI) in primary care. Thorax 2005; 61:75-9. [PMID: 16227331 PMCID: PMC2080713 DOI: 10.1136/thx.2004.027441] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Lower respiratory tract infections (LRTI) are a common reason for consulting general practitioners (GPs). In most cases the aetiology is unknown, yet most result in an antibiotic prescription. The aetiology of LRTI was investigated in a prospective controlled study. METHODS Eighty adults presenting to GPs with acute LRTI were recruited together with 49 controls over 12 months. Throat swabs, nasal aspirates (patients and controls), and sputum (patients) were obtained and polymerase chain reaction (PCR) and reverse transcriptase polymerase chain reaction (RT-PCR) assays were used to detect Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, influenza viruses (AH1, AH3 and B), parainfluenza viruses 1-3, coronaviruses, respiratory syncytial virus, adenoviruses, rhinoviruses, and enteroviruses. Standard sputum bacteriology was also performed. Outcome was recorded at a follow up visit. RESULTS Potential pathogens were identified in 55 patients with LRTI (69%) and seven controls (14%; p<0.0001). The identification rate was 63% (viruses) and 26% (bacteria) for patients and 12% (p<0.0001) and 6% (p = 0.013), respectively, for controls. The most common organisms identified in the patients were rhinoviruses (33%), influenza viruses (24%), and Streptococcus pneumoniae (19%) compared with 2% (p<0.001), 6% (p = 0.013), and 4% (p = 0.034), respectively, in controls. Multiple pathogens were identified in 18 of the 80 LRTI patients (22.5%) and in two of the 49 controls (4%; p = 0.011). Atypical organisms were rarely identified. Cases with bacterial aetiology were clinically indistinguishable from those with viral aetiology. CONCLUSION Patients presenting to GPs with acute adult LRTI predominantly have a viral illness which is most commonly caused by rhinoviruses and influenza viruses.
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Amols H, Chang J, De Arruda F, Sillanpaa J, Yorke E, Hertanto A, Pham H, Rosenzweig K, Ling C, Seppi E, Mageras G. Observation of Interfractional Variations in Lung Tumor Position Using Megavoltage Cone-Beam CT. Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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96
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Pugachev A, Claus F, Sun X, Ruan S, Cai S, Koziorowsky J, Finn R, O”Donoghue J, Ling C, Humm J. MO-D-I-609-08: Validation of PET Hypoxia Tracers by Autoradiography and Fluorescent Microscopy. Med Phys 2005. [DOI: 10.1118/1.1998244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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97
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Ling C. MO-D-J-6C-04: Tumor Hypoxia Imaging. Med Phys 2005. [DOI: 10.1118/1.1999685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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98
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Wang P, Lovelock D, Yamada Y, Amols H, Ling C. SU-FF-J-41: Monitoring of Intra-Fractional Patient Motion During High-Dose Extra-Cranial Paraspinal Radiosurgery. Med Phys 2005. [DOI: 10.1118/1.1997587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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99
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Chan H, Zelefsky M, Fuks Z, Hunt M, Ling C, Leibel S. Long-term outcome of high dose intensity modulated radiotherapy for clinically localized prostate cancer. Int J Radiat Oncol Biol Phys 2004. [DOI: 10.1016/j.ijrobp.2004.06.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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100
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Zelefsky M, Fuks Z, Chan H, Ling C, Hunt M, Leibel S. Ten-year results of dose escalation with 3-dimensional conformal radiotherapy for patients with clinically localized prostate cancer. Int J Radiat Oncol Biol Phys 2003. [DOI: 10.1016/s0360-3016(03)00920-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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