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Chiu T, Long T, Modiri A, Tian Z, Sawant A, Yan Y, Jiang S, Gu X. TH-EF-BRB-04: 4π Dynamic Conformal Arc Therapy Dynamic Conformal Arc Therapy (DCAT) for SBRT. Med Phys 2016. [DOI: 10.1118/1.4958250] [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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Long T, Chen M, Jiang S, Lu W. SU-C-BRB-07: Threshold-Driven Optimization for Reference-Based Auto-Planning. Med Phys 2016. [DOI: 10.1118/1.4955561] [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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Long T, Loizidou M, Schettino G, Royle G, Ricketts K. PV-0429: A 3D in vitro cancer model and imaging platform to measure proton radiation-induced cellular damage. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)31678-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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George IJ, Hays MD, Herrington JS, Preston W, Snow R, Faircloth J, George BJ, Long T, Baldauf RW. Effects of Cold Temperature and Ethanol Content on VOC Emissions from Light-Duty Gasoline Vehicles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:13067-13074. [PMID: 26444830 DOI: 10.1021/acs.est.5b04102] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Emissions of speciated volatile organic compounds (VOCs), including mobile source air toxics (MSATs), were measured in vehicle exhaust from three light-duty spark ignition vehicles operating on summer and winter grade gasoline (E0) and ethanol blended (E10 and E85) fuels. Vehicle testing was conducted using a three-phase LA92 driving cycle in a temperature-controlled chassis dynamometer at two ambient temperatures (-7 and 24 °C). The cold start driving phase and cold ambient temperature increased VOC and MSAT emissions up to several orders of magnitude compared to emissions during other vehicle operation phases and warm ambient temperature testing, respectively. As a result, calculated ozone formation potentials (OFPs) were 7 to 21 times greater for the cold starts during cold temperature tests than comparable warm temperature tests. The use of E85 fuel generally led to substantial reductions in hydrocarbons and increases in oxygenates such as ethanol and acetaldehyde compared to E0 and E10 fuels. However, at the same ambient temperature, the VOC emissions from the E0 and E10 fuels and OFPs from all fuels were not significantly different. Cold temperature effects on cold start MSAT emissions varied by individual MSAT compound, but were consistent over a range of modern spark ignition vehicles.
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Luo Z, Zeng W, Tang W, Long T, Zhang J, Xie X, Kuang Y, Chen M, Su J, Chen X. CD147 interacts with NDUFS6 in regulating mitochondrial complex I activity and the mitochondrial apoptotic pathway in human malignant melanoma cells. Curr Mol Med 2015; 14:1252-64. [PMID: 25470292 DOI: 10.2174/1566524014666141202144601] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 09/03/2013] [Accepted: 02/24/2014] [Indexed: 11/22/2022]
Abstract
Malignant melanoma (MM) is one of the most lethal tumors and is characterized by high invasiveness, frequent metastasis, and resistance to chemotherapy. The risk of metastatic MM is accompanied by disordered energy metabolism involving the oxidative phosphorylation (OXPHOS) process, which is largely carried out in mitochondrial complexes. Complex I is the first and largest mitochondrial enzyme complex associated with this process. CD147 is a transmembrane glycoprotein mainly expressed on the cell surface, and also appears in the cytoplasm in some tumors. We found that CD147 is often translocated to the cytoplasm in metastatic MM specimens as compared to primary MM. We also demonstrated high expression of CD147 in isolated mitochondrial fractions of A375 cells. The yeast two-hybrid (Y2H) assay identified NDUFS6 (which encodes a subunit of mitochondrial respiratory chain complex I) as a candidate that interacts with CD147 and depletion of CD147 in A375 cells significantly decreased complex I enzyme activity. We also showed that CD147 increased the viability of A375 cells exposed to berberine-induced mitochondrial damage, and protected them from apoptosis through a mitochondrial-dependent pathway. This finding was confirmed by adding exogenous Bcl-2 to A375 cell cultures. In summary, our results identify the existence of CD147 in human melanoma cell mitochondria. They indicate that CD147 appears to regulate complex I activity and apoptosis in MM by interacting with mitochondrial NDUFS6. Our findings provide new insight into the function of CD147 and identify it as a promising therapeutic target in melanoma through disruption of the energy metabolism.
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Book EK, Snow R, Long T, Fang T, Baldauf R. Temperature effects on particulate emissions from DPF-equipped diesel trucks operating on conventional and biodiesel fuels. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2015; 65:751-8. [PMID: 25976488 DOI: 10.1080/10962247.2014.984817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
UNLABELLED Emissions tests were conducted on two medium heavy-duty diesel trucks equipped with a particulate filter (DPF), with one vehicle using a NOx absorber and the other a selective catalytic reduction (SCR) system for control of nitrogen oxides (NOx). Both vehicles were tested with two different fuels (ultra-low-sulfur diesel [ULSD] and biodiesel [B20]) and ambient temperatures (70ºF and 20ºF), while the truck with the NOx absorber was also operated at two loads (a heavy weight and a light weight). The test procedure included three driving cycles, a cold start with low transients (CSLT), the federal heavy-duty urban dynamometer driving schedule (UDDS), and a warm start with low transients (WSLT). Particulate matter (PM) emissions were measured second-by-second using an Aethalometer for black carbon (BC) concentrations and an engine exhaust particle sizer (EEPS) for particle count measurements between 5.6 and 560 nm. The DPF/NOx absorber vehicle experienced increased BC and particle number concentrations during cold starts under cold ambient conditions, with concentrations two to three times higher than under warm starts at higher ambient temperatures. The average particle count for the UDDS showed an opposite trend, with an approximately 27% decrease when ambient temperatures decreased from 70ºF to 20ºF. This vehicle experienced decreased emissions when going from ULSD to B20. The DPF/SCR vehicle tested had much lower emissions, with many of the BC and particle number measurements below detectable limits. However, both vehicles did experience elevated emissions caused by DPF regeneration. All regeneration events occurred during the UDDS cycle. Slight increases in emissions were measured during the WSLT cycles after the regeneration. However, the day after a regeneration occurred, both vehicles showed significant increases in particle number and BC for the CSLT drive cycle, with increases from 93 to 1380% for PM number emissions compared with tests following a day with no regeneration. IMPLICATIONS The use of diesel particulate filters (DPFs) on trucks is becoming more common throughout the world. Understanding how DPFs affect air pollution emissions under varying operating conditions will be critical in implementing effective air quality standards. This study evaluated particulate matter (PM) and black carbon (BC) emissions with two DPF-equipped heavy-duty diesel trucks operating on conventional fuel and a biodiesel fuel blend at varying ambient temperatures, loads, and drive cycles.
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Veiga C, Long T, Siow B, Loizidou M, Royle G, Ricketts K. MO-F-CAMPUS-I-04: Magnetic Resonance Imaging of An in Vitro 3D Tumor Model. Med Phys 2015. [DOI: 10.1118/1.4925470] [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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Long T, McDougal OM, Andersen T. GAMPMS: Genetic algorithm managed peptide mutant screening. J Comput Chem 2015; 36:1304-10. [DOI: 10.1002/jcc.23928] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 03/01/2015] [Accepted: 04/05/2015] [Indexed: 11/06/2022]
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George IJ, Hays MD, Snow R, Faircloth J, George BJ, Long T, Baldauf RW. Cold temperature and biodiesel fuel effects on speciated emissions of volatile organic compounds from diesel trucks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:14782-9. [PMID: 25393130 DOI: 10.1021/es502949a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Speciated volatile organic compounds (VOCs) were measured in diesel exhaust from three heavy-duty trucks equipped with modern aftertreatment technologies. Emissions testing was conducted on a chassis dynamometer at two ambient temperatures (-7 and 22 °C) operating on two fuels (ultra low sulfur diesel and 20% soy biodiesel blend) over three driving cycles: cold start, warm start and heavy-duty urban dynamometer driving cycle. VOCs were measured separately for each drive cycle. Carbonyls such as formaldehyde and acetaldehyde dominated VOC emissions, making up ∼ 72% of the sum of the speciated VOC emissions (∑VOCs) overall. Biodiesel use led to minor reductions in aromatics and variable changes in carbonyls. Cold temperature and cold start conditions caused dramatic enhancements in VOC emissions, mostly carbonyls, compared to the warmer temperature and other drive cycles, respectively. Different 2007+ aftertreatment technologies involving catalyst regeneration led to significant modifications of VOC emissions that were compound-specific and highly dependent on test conditions. A comparison of this work with emission rates from different diesel engines under various test conditions showed that these newer technologies resulted in lower emission rates of aromatic compounds. However, emissions of other toxic partial combustion products such as carbonyls were not reduced in the modern diesel vehicles tested.
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Breen MS, Schultz BD, Sohn MD, Long T, Langstaff J, Williams R, Isaacs K, Meng QY, Stallings C, Smith L. A review of air exchange rate models for air pollution exposure assessments. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2014; 24:555-63. [PMID: 23715084 DOI: 10.1038/jes.2013.30] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 02/28/2013] [Accepted: 03/15/2013] [Indexed: 05/05/2023]
Abstract
A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings where people spend their time. The AER, which is the rate of exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pollutants and for removal of indoor-emitted air pollutants. This paper presents an overview and critical analysis of the scientific literature on empirical and physically based AER models for residential and commercial buildings; the models highlighted here are feasible for exposure assessments as extensive inputs are not required. Models are included for the three types of airflows that can occur across building envelopes: leakage, natural ventilation, and mechanical ventilation. Guidance is provided to select the preferable AER model based on available data, desired temporal resolution, types of airflows, and types of buildings included in the exposure assessment. For exposure assessments with some limited building leakage or AER measurements, strategies are described to reduce AER model uncertainty. This review will facilitate the selection of AER models in support of air pollution exposure assessments.
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Stevenson D, Long T, Green J, Rose J. 109 Measuring Albuterol-Induced Changes in Whole-Blood Potassium Levels in the Healthy Patient. Ann Emerg Med 2014. [DOI: 10.1016/j.annemergmed.2014.07.135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Long T, Sprenger CC, Coleman I, Nelson P, Ratner B, Plymate S. Abstract 1100: Macrophage infiltration is associated with release from dormancy in a novel model of dormant prostate cancer. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-1100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Circulating tumor cells are found in approximately 70% of men with prostate cancer at the time of primary treatment. Less than a third of these men will develop recurrent cancer within 20 years of primary treatment, suggesting that only a subset of dormant tumor cells are able to escape dormancy and develop into clinical metastases. Escape from dormancy, though, is clinically significant since these men are at greatest risk of dying from prostate cancer. Mechanisms by which cancer cells escape dormancy are poorly understood and very few models exist to study dormancy, especially in prostate cancer. We previously found that when a dormant prostate cancer cell line was seeded into a bioscaffold and placed in vivo, tumor formation was detected after 6-8 weeks, whereas no growth was seen up to six months after the dormant cells were injected s.c. with Matrigel. Analysis of the tumors revealed significantly greater macrophage infiltration into the scaffold tumors. Gene expression and cytokine antibody arrays demonstrated increased expression of macrophage associated cytokines in scaffold tumors. While macrophages have been implicated in metastatic spread of various cancers, their role in escape from dormancy has not been elucidated.
Objective: To determine if macrophages play a role in escape from tumor dormancy in prostate cancer.
Methods: In vitro we cultured a dormant prostate cancer cell line, M12mac25, with macrophage conditioned media and then examined proliferation and gene expression. In vivo, mice were implanted with sphere-templated polyHEMA bioscaffolds pre-seeded with M12mac25 cells. To inhibit macrophage activity, mice received s.c. injections of clondronate liposomes or PBS liposomes as a control for 6 weeks.
Results: In vitro culture of M12mac25 cells with macrophage-derived conditioned medium led to increased proliferation of the M12mac25 cells and similarly upregulated genes as those seen the in vivo bioscaffold-derived tumors. In vitro treatment of primary bone-marrow derived macrophages with clondronate liposomes resulted in apoptosis while exposure to PBS liposomes did not affect the macrophages. In contrast, M12mac25 cells were not affected by either PBS or clondronate liposomes. In vivo, clondronate liposomes effectively eliminated macrophages from the M12mac25 seeded scaffolds and prevented tumor growth in these scaffolds.
Interpretation: Macrophages contribute to M12mac25 escape from dormancy.
Citation Format: Thomas Long, Cynthia C. Sprenger, Ilsa Coleman, Peter Nelson, Buddy Ratner, Stephen Plymate. Macrophage infiltration is associated with release from dormancy in a novel model of dormant prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1100. doi:10.1158/1538-7445.AM2014-1100
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Long T, Stevenson D, Green J, Rose J. 263 Measuring Albuterol-Induced Lactic Acidosis in the Healthy Patient. Ann Emerg Med 2014. [DOI: 10.1016/j.annemergmed.2014.07.290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Zeng W, Su J, Wu L, Yang D, Long T, Li D, Kuang Y, Li J, Qi M, Zhang J, Chen X. CD147 promotes melanoma progression through hypoxia-induced MMP2 activation. Curr Mol Med 2014; 14:163-73. [PMID: 24090196 DOI: 10.2174/15665240113136660077] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 09/25/2013] [Accepted: 09/27/2013] [Indexed: 11/22/2022]
Abstract
Hypoxia enhances MMP2 expression and the invasion and metastatic potential of melanoma cells. CD147 has been shown to induce MMP2 in multiple cancers. To investigate the role of CD147 in hypoxiainduced MMP2 activation, we performed immunohistochemistry (IHC) staining in 206 normal and melanoma tissue samples, and analyzed the correlation between HIF1α and CD147. ChIP (chromosome Immunoprecipitation) in melanoma cell lines supports that HIF1α directly binds to CD147 promoter. Moreover, we made a series of deletion mutants of CD147 promoter, and identified a conserved HIF1α binding site. Point mutation in this site significantly decreased CD147 response to hypoxia. Importantly, knocking down CD147 attenuates MMP2 response to hypoxia in melanoma cell lines. MMP2 could not be efficiently activated by hypoxia in CD147 depletion cells. ELISA data showed that MMP2 secretion was reduced in CD147 depletion cells than control under hypoxia condition. To verify the data from cell culture model, we performed in vivo mouse xenograft experiment. IHC staining showed reduced MMP2 level in CD147 depleted xenografts compared to the control group, with the HIF1α level being comparable. Our study demonstrates a novel pathway mediated by CD147 to promote the MMP2 activation induced by hypoxia, and helps to understand the interplay between hypoxia and melanoma progression.
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Finigan V, Long T. Skin-to-skin contact: multicultural perspectives on birth fluids and birth 'dirt'. Int Nurs Rev 2014; 61:270-7. [PMID: 24712443 PMCID: PMC4265244 DOI: 10.1111/inr.12100] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aim To explore the experiences of women from three population groups of immediate skin-to-skin contact (SSC) with their newborn babies. Method A mixed methods approach was adopted in a phenomenological study to elicit the experiences of English, Pakistani and Bangladeshi women. Audiotaped diaries, semi-structured interviews, photographs and video recordings were employed. Concept mapping was central to data analysis. Results This paper reports novel findings that women contextualized and accepted secretions and bodily fluids from birth. This contradicts the beliefs of midwives that Asian women find bodily secretions abhorrent and culturally unacceptable. All participants reported positive experiences of SSC despite varying degrees of soiling from birth fluids. Limitations The study was conducted in a single setting, and participants may not have been representative of others in their cultural groups. Third-party translation may have added an unsought layer of interpretation. The imposition of cultural expectations by peers in the recruitment process excluded some potential participants. Conclusion Stereotypical assumptions about cultural background often characterize professional responses. When this stereotyping was put aside, women of all three cultures, whether breastfeeding or bottle-feeding, were able to enjoy SSC with their babies. Implications for Nursing and Health Policy The findings suggest that changes will be needed in professional practice to be more open to women's expressed preferences, in local policy to ensure that choices are made clear and are available, and in national strategic direction to ensure widespread adoption of positive practices for opportunities to increase breastfeeding, promote parent–child bonding and support patient choice to be realized.
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Hays MD, Preston W, George BJ, Schmid J, Baldauf R, Snow R, Robinson JR, Long T, Faircloth J. Carbonaceous aerosols emitted from light-duty vehicles operating on gasoline and ethanol fuel blends. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:14502-9. [PMID: 24246086 DOI: 10.1021/es403096v] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This study examines the chemical properties of carbonaceous aerosols emitted from three light-duty gasoline vehicles (LDVs) operating on gasoline (e0) and ethanol-gasoline fuel blends (e10 and e85). Vehicle road load simulations were performed on a chassis dynamometer using the three-phase LA-92 unified driving cycle (UDC). Effects of LDV operating conditions and ambient temperature (-7 and 24 °C) on particle-phase semivolatile organic compounds (SVOCs) and organic and elemental carbon (OC and EC) emissions were investigated. SVOC concentrations and OC and EC fractions were determined with thermal extraction-gas chromatography-mass spectrometry (TE-GC-MS) and thermal-optical analysis (TOA), respectively. LDV aerosol emissions were predominantly carbonaceous, and EC/PM (w/w) decreased linearly with increasing fuel ethanol content. TE-GC-MS analysis accounted for up to 4% of the fine particle (PM2.5) mass, showing the UDC phase-integrated sum of identified SVOC emissions ranging from 0.703 μg km(-1) to 18.8 μg km(-1). Generally, higher SVOC emissions were associated with low temperature (-7 °C) and engine ignition; mixed regression models suggest these emissions rate differences are significant. Use of e85 significantly reduced the emissions of lower molecular weight PAH. However, a reduction in higher molecular weight PAH entities in PM was not observed. Individual SVOC emissions from the Tier 2 LDVs and fuel technologies tested are substantially lower and distributed differently than those values populating the United States emissions inventories currently. Hence, this study is likely to influence future apportionment, climate, and air quality model predictions that rely on source combustion measurements of SVOCs in PM.
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Zeng W, Su J, Wu L, Yang D, Long T, Li D, Kuang Y, Li J, Zhang J, Ruben Agregan XC. CD147 Promotes Melanoma Progression Through Hypoxia-Induced MMP2 Activation. Curr Mol Med 2013. [DOI: 10.2174/15665240111888131028123217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Wang B, Stender B, Long T, Zhang Z, Schlaefer A. An approach to validate ultrasound surface segmentation of the heart. ACTA ACUST UNITED AC 2013; 58 Suppl 1:/j/bmte.2013.58.issue-s1-L/bmt-2013-4283/bmt-2013-4283.xml. [PMID: 24042938 DOI: 10.1515/bmt-2013-4283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Zarepisheh M, Long T, Li N, Romeijn E, Jia X, Jiang S. TH-A-116-09: A Novel Prior-Knowledge-Based Optimization Algorithm for Automatic Treatment Planning and Adaptive Radiotherapy Re-Planning. Med Phys 2013. [DOI: 10.1118/1.4815738] [Citation(s) in RCA: 2] [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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Long T, Xu J, McClure SR, Amin V, Haynes J. Potential femoral head osteonecrosis model induced by high-intensity focused ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1056-1065. [PMID: 23453377 DOI: 10.1016/j.ultrasmedbio.2012.12.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 10/09/2012] [Accepted: 12/31/2012] [Indexed: 06/01/2023]
Abstract
Osteonecrosis of the femoral head is a common disease that can result in complex hip replacement. To evaluate potential treatments, a model that consistently creates osteonecrosis is needed. We studied and demonstrated the possibility of developing an osteonecrosis model using high-intensity focused ultrasound (HIFU) on canine femora in vitro. To achieve these goals, the temperature in the medullary cavity of the femoral head was measured. A phenomenological model was developed to fit the measured temperature variations with the HIFU parameters for similar HIFU experiments on femoral heads. The average temperature discrepancy between model and measured values was less than 0.83°C. Histology confirmed that the temperature in the medullary cavity can be elevated to a level at which an acute thermal injury is created. HIFU has the potential to be used in a non-invasive model of osteonecrosis.
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Dong P, Nguyen D, Long T, Ruan D, Romeijn E, Low D, Sheng K. TH-C-137-02: Robotic Radiotherapy Using Intermediate Beam Energies. Med Phys 2013. [DOI: 10.1118/1.4815745] [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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Long T, Matuszak M, Schipper M, Epelman M, Kong F, Ten Haken R, Romeijn E. MO-A-137-06: A Stochastic Optimization Approach to Adaptive Lung Radiation Therapy Treatment Planning. Med Phys 2013. [DOI: 10.1118/1.4815209] [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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Dong P, Nguyen D, Ruan D, Romeijn E, Long T, Kupelian P, Yang Y, Low D, King C, Steinberg M, Sheng K. SU-E-T-657: Prostate Robotic Radiotherapy On Conventional C-Arm Linacs. Med Phys 2013. [DOI: 10.1118/1.4815084] [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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Dong P, McCloskey S, Yang Y, Long T, Ruan D, Romeijn E, Low D, Kupelian P, Sheng K. 4Pi Therapy for Partial Breast Irradiation. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.647] [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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Long T, Matuszak M, Feng M, Fraass BA, Ten Haken RK, Romeijn HE. Sensitivity analysis for lexicographic ordering in radiation therapy treatment planning. Med Phys 2012; 39:3445-55. [PMID: 22755724 DOI: 10.1118/1.4720218] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To introduce a method to efficiently identify and calculate meaningful tradeoffs between criteria in an interactive IMRT treatment planning procedure. The method provides a systematic approach to developing high-quality radiation therapy treatment plans. METHODS Treatment planners consider numerous dosimetric criteria of varying importance that, when optimized simultaneously through multicriteria optimization, yield a Pareto frontier which represents the set of Pareto-optimal treatment plans. However, generating and navigating this frontier is a time-consuming, nontrivial process. A lexicographic ordering (LO) approach to IMRT uses a physician's criteria preferences to partition the treatment planning decisions into a multistage treatment planning model. Because the relative importance of criteria optimized in the different stages may not necessarily constitute a strict prioritization, the authors introduce an interactive process, sensitivity analysis in lexicographic ordering (SALO), to allow the treatment planner control over the relative sequential-stage tradeoffs. By allowing this flexibility within a structured process, SALO implicitly restricts attention to and allows exploration of a subset of the Pareto efficient frontier that the physicians have deemed most important. RESULTS Improvements to treatment plans over a LO approach were found by implementing the SALO procedure on a brain case and a prostate case. In each stage, a physician assessed the tradeoff between previous stage and current stage criteria. The SALO method provided critical tradeoff information through curves approximating the relationship between criteria, which allowed the physician to determine the most desirable treatment plan. CONCLUSIONS The SALO procedure provides treatment planners with a directed, systematic process to treatment plan selection. By following a physician's prioritization, the treatment planner can avoid wasting effort considering clinically inferior treatment plans. The planner is guided by criteria importance, but given the information necessary to accurately adjust the relative importance at each stage. Through these attributes, the SALO procedure delivers an approach well balanced between efficiency and flexibility.
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