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Associations of alcohol and cannabis use with change in posttraumatic stress disorder and depression symptoms over time in recently trauma-exposed individuals
- Cecilia A. Hinojosa, Amanda Liew, Xinming An, Jennifer S. Stevens, Archana Basu, Sanne J. H. van Rooij, Stacey L. House, Francesca L. Beaudoin, Donglin Zeng, Thomas C. Neylan, Gari D. Clifford, Tanja Jovanovic, Sarah D. Linnstaedt, Laura T. Germine, Scott L. Rauch, John P. Haran, Alan B. Storrow, Christopher Lewandowski, Paul I. Musey, Phyllis L. Hendry, Sophia Sheikh, Christopher W. Jones, Brittany E. Punches, Michael C. Kurz, Robert A. Swor, Lauren A. Hudak, Jose L. Pascual, Mark J. Seamon, Elizabeth M. Datner, Anna M. Chang, Claire Pearson, David A. Peak, Roland C. Merchant, Robert M. Domeier, Niels K. Rathlev, Paulina Sergot, Leon D. Sanchez, Steven E. Bruce, Mark W. Miller, Robert H. Pietrzak, Jutta Joormann, Diego A. Pizzagalli, John F. Sheridan, Steven E. Harte, James M. Elliott, Ronald C. Kessler, Karestan C. Koenen, Samuel A. McLean, Kerry J. Ressler, Negar Fani
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- Journal:
- Psychological Medicine / Volume 54 / Issue 2 / January 2024
- Published online by Cambridge University Press:
- 13 June 2023, pp. 338-349
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Background
Several hypotheses may explain the association between substance use, posttraumatic stress disorder (PTSD), and depression. However, few studies have utilized a large multisite dataset to understand this complex relationship. Our study assessed the relationship between alcohol and cannabis use trajectories and PTSD and depression symptoms across 3 months in recently trauma-exposed civilians.
MethodsIn total, 1618 (1037 female) participants provided self-report data on past 30-day alcohol and cannabis use and PTSD and depression symptoms during their emergency department (baseline) visit. We reassessed participant's substance use and clinical symptoms 2, 8, and 12 weeks posttrauma. Latent class mixture modeling determined alcohol and cannabis use trajectories in the sample. Changes in PTSD and depression symptoms were assessed across alcohol and cannabis use trajectories via a mixed-model repeated-measures analysis of variance.
ResultsThree trajectory classes (low, high, increasing use) provided the best model fit for alcohol and cannabis use. The low alcohol use class exhibited lower PTSD symptoms at baseline than the high use class; the low cannabis use class exhibited lower PTSD and depression symptoms at baseline than the high and increasing use classes; these symptoms greatly increased at week 8 and declined at week 12. Participants who already use alcohol and cannabis exhibited greater PTSD and depression symptoms at baseline that increased at week 8 with a decrease in symptoms at week 12.
ConclusionsOur findings suggest that alcohol and cannabis use trajectories are associated with the intensity of posttrauma psychopathology. These findings could potentially inform the timing of therapeutic strategies.
Childhood adversities and risk of posttraumatic stress disorder and major depression following a motor vehicle collision in adulthood
- H. N. Ziobrowski, B. Holt-Gosselin, M. V. Petukhova, A. J. King, S. Lee, S. L. House, F. L. Beaudoin, X. An, J. S. Stevens, D. Zeng, T. C. Neylan, G. D. Clifford, S. D. Linnstaedt, L. T. Germine, K. A. Bollen, S. L. Rauch, J. P. Haran, A. B. Storrow, C. Lewandowski, P. I. Musey, P. L. Hendry, S. Sheikh, C. W. Jones, B. E. Punches, M. C. Kurz, R. A. Swor, L. A. Hudak, J. L. Pascual, M. J. Seamon, E. Harris, C. Pearson, R. C. Merchant, R. M. Domeier, N. K. Rathlev, B. J. O'Neil, P. Sergot, L. D. Sanchez, S. E. Bruce, M. W. Miller, R. H. Pietrzak, J. Joormann, D. M. Barch, D. A. Pizzagalli, S. E. Harte, J. M. Elliott, K. J. Ressler, S. A. McLean, K. C. Koenen, R. C. Kessler
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- Journal:
- Epidemiology and Psychiatric Sciences / Volume 32 / 2023
- Published online by Cambridge University Press:
- 10 January 2023, e1
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Aims
Childhood adversities (CAs) predict heightened risks of posttraumatic stress disorder (PTSD) and major depressive episode (MDE) among people exposed to adult traumatic events. Identifying which CAs put individuals at greatest risk for these adverse posttraumatic neuropsychiatric sequelae (APNS) is important for targeting prevention interventions.
MethodsData came from n = 999 patients ages 18–75 presenting to 29 U.S. emergency departments after a motor vehicle collision (MVC) and followed for 3 months, the amount of time traditionally used to define chronic PTSD, in the Advancing Understanding of Recovery After Trauma (AURORA) study. Six CA types were self-reported at baseline: physical abuse, sexual abuse, emotional abuse, physical neglect, emotional neglect and bullying. Both dichotomous measures of ever experiencing each CA type and numeric measures of exposure frequency were included in the analysis. Risk ratios (RRs) of these CA measures as well as complex interactions among these measures were examined as predictors of APNS 3 months post-MVC. APNS was defined as meeting self-reported criteria for either PTSD based on the PTSD Checklist for DSM-5 and/or MDE based on the PROMIS Depression Short-Form 8b. We controlled for pre-MVC lifetime histories of PTSD and MDE. We also examined mediating effects through peritraumatic symptoms assessed in the emergency department and PTSD and MDE assessed in 2-week and 8-week follow-up surveys. Analyses were carried out with robust Poisson regression models.
ResultsMost participants (90.9%) reported at least rarely having experienced some CA. Ever experiencing each CA other than emotional neglect was univariably associated with 3-month APNS (RRs = 1.31–1.60). Each CA frequency was also univariably associated with 3-month APNS (RRs = 1.65–2.45). In multivariable models, joint associations of CAs with 3-month APNS were additive, with frequency of emotional abuse (RR = 2.03; 95% CI = 1.43–2.87) and bullying (RR = 1.44; 95% CI = 0.99–2.10) being the strongest predictors. Control variable analyses found that these associations were largely explained by pre-MVC histories of PTSD and MDE.
ConclusionsAlthough individuals who experience frequent emotional abuse and bullying in childhood have a heightened risk of experiencing APNS after an adult MVC, these associations are largely mediated by prior histories of PTSD and MDE.
Prior differences in previous trauma exposure primarily drive the observed racial/ethnic differences in posttrauma depression and anxiety following a recent trauma
- N. G. Harnett, N. M. Dumornay, M. Delity, L. D. Sanchez, K. Mohiuddin, P. I. Musey, Jr., M. J. Seamon, S. A. McLean, R. C. Kessler, K. C. Koenen, F. L. Beaudoin, L. A. M. Lebois, S. J. H. van Rooij, N. A. Sampson, V. Michopoulos, J. L. Maples-Keller, J. P. Haran, A. B. Storrow, C. Lewandowski, P. L. Hendry, S. Sheikh, C. W. Jones, B. E. Punches, M. C. Kurz, R. A. Swor, M. E. McGrath, L. A. Hudak, J. L. Pascual, S. L. House, X. An, J. S. Stevens, T. C. Neylan, T. Jovanovic, S. D. Linnstaedt, L. T. Germine, E. M. Datner, A. M. Chang, C. Pearson, D. A. Peak, R. C. Merchant, R. M. Domeier, N. K. Rathlev, B. J. O'Neil, P. Sergot, S. E. Bruce, M. W. Miller, R. H. Pietrzak, J. Joormann, D. M. Barch, D. A. Pizzagalli, J. F. Sheridan, J. W. Smoller, B. Luna, S. E. Harte, J. M. Elliott, K. J. Ressler
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- Journal:
- Psychological Medicine / Volume 53 / Issue 6 / April 2023
- Published online by Cambridge University Press:
- 31 January 2022, pp. 2553-2562
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Background
Racial and ethnic groups in the USA differ in the prevalence of posttraumatic stress disorder (PTSD). Recent research however has not observed consistent racial/ethnic differences in posttraumatic stress in the early aftermath of trauma, suggesting that such differences in chronic PTSD rates may be related to differences in recovery over time.
MethodsAs part of the multisite, longitudinal AURORA study, we investigated racial/ethnic differences in PTSD and related outcomes within 3 months after trauma. Participants (n = 930) were recruited from emergency departments across the USA and provided periodic (2 weeks, 8 weeks, and 3 months after trauma) self-report assessments of PTSD, depression, dissociation, anxiety, and resilience. Linear models were completed to investigate racial/ethnic differences in posttraumatic dysfunction with subsequent follow-up models assessing potential effects of prior life stressors.
ResultsRacial/ethnic groups did not differ in symptoms over time; however, Black participants showed reduced posttraumatic depression and anxiety symptoms overall compared to Hispanic participants and White participants. Racial/ethnic differences were not attenuated after accounting for differences in sociodemographic factors. However, racial/ethnic differences in depression and anxiety were no longer significant after accounting for greater prior trauma exposure and childhood emotional abuse in White participants.
ConclusionsThe present findings suggest prior differences in previous trauma exposure partially mediate the observed racial/ethnic differences in posttraumatic depression and anxiety symptoms following a recent trauma. Our findings further demonstrate that racial/ethnic groups show similar rates of symptom recovery over time. Future work utilizing longer time-scale data is needed to elucidate potential racial/ethnic differences in long-term symptom trajectories.
Socio-demographic and trauma-related predictors of depression within eight weeks of motor vehicle collision in the AURORA study
- Jutta Joormann, Samuel A. McLean, Francesca L. Beaudoin, Xinming An, Jennifer S. Stevens, Donglin Zeng, Thomas C. Neylan, Gari Clifford, Sarah D. Linnstaedt, Laura T. Germine, Scott L. Rauch, Paul I. Musey, Phyllis L. Hendry, Sophia Sheikh, Christopher W. Jones, Brittany E. Punches, Gregory Fermann, Lauren A. Hudak, Kamran Mohiuddin, Vishnu Murty, Meghan E. McGrath, John P. Haran, Jose Pascual, Mark Seamon, David A. Peak, Claire Pearson, Robert M. Domeier, Paulina Sergot, Roland Merchant, Leon D. Sanchez, Niels K. Rathlev, William F. Peacock, Steven E. Bruce, Deanna Barch, Diego A. Pizzagalli, Beatriz Luna, Steven E. Harte, Irving Hwang, Sue Lee, Nancy Sampson, Karestan C. Koenen, Kerry J. Ressler, Ronald C. Kessler
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- Journal:
- Psychological Medicine / Volume 52 / Issue 10 / July 2022
- Published online by Cambridge University Press:
- 29 October 2020, pp. 1934-1947
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Background
This is the first report on the association between trauma exposure and depression from the Advancing Understanding of RecOvery afteR traumA(AURORA) multisite longitudinal study of adverse post-traumatic neuropsychiatric sequelae (APNS) among participants seeking emergency department (ED) treatment in the aftermath of a traumatic life experience.
MethodsWe focus on participants presenting at EDs after a motor vehicle collision (MVC), which characterizes most AURORA participants, and examine associations of participant socio-demographics and MVC characteristics with 8-week depression as mediated through peritraumatic symptoms and 2-week depression.
ResultsEight-week depression prevalence was relatively high (27.8%) and associated with several MVC characteristics (being passenger v. driver; injuries to other people). Peritraumatic distress was associated with 2-week but not 8-week depression. Most of these associations held when controlling for peritraumatic symptoms and, to a lesser degree, depressive symptoms at 2-weeks post-trauma.
ConclusionsThese observations, coupled with substantial variation in the relative strength of the mediating pathways across predictors, raises the possibility of diverse and potentially complex underlying biological and psychological processes that remain to be elucidated in more in-depth analyses of the rich and evolving AURORA database to find new targets for intervention and new tools for risk-based stratification following trauma exposure.
P.072 Agreement between children and their parents’ ratings of the health-related quality of life of children with Duchenne Muscular Dystrophy
- S Brar, C Campbell, E McColl, W Martens, M McDermott, R Tawil, K Hart, B Herr, J Kirschner, M Guglieri, R Griggs, The Muscle Study Group ()
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- Journal:
- Canadian Journal of Neurological Sciences / Volume 45 / Issue s2 / June 2018
- Published online by Cambridge University Press:
- 27 June 2018, p. S35
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Background: When measuring young Duchenne Muscular Dystrophy (DMD) patients’ health-related quality of life (HRQoL), parent-proxy reports are heavily relied on. Therefore, it is imperative that the relationship between parent-proxy and child self-report HRQoL is understood. This study examined the level of agreement between children and their parent-proxy rating of the child’s HRQoL. Methods: We used FOR-DMD clinical trial baseline data. HRQoL, measured using the PedsQL inventory, was reported by 178 parent and child (ages 4 to 7 years) dyads. Intracorrelation coefficients (ICC) measured absolute agreement while paired t-tests determined differences in the average HRQoL ratings between groups. Results: The level of agreement between child and parent-proxy ratings of HRQoL was poor for the generic PedsQL scale (ICC: 0.29) and its subscales; and, similarly low for the neuromuscular disease module (ICC:0.16). On average, parents rated their child’s HRQoL as poorer than the children rated themselves in all scales except for psychosocial and school functioning. Conclusions: Child and parent-proxy HRQoL ratings are discordant in this study sample, as occurs in other chronic pediatric diseases. This should be taken into account when interpreting clinical and research HRQoL findings in this population. Future studies should examine reasons for parents’ perception of poorer HRQoL than that reported by their children.
P103: Performance characteristics of the modified Sgarbossa criteria for diagnosis of acute coronary occlusion in emergency department patients with ventricular paced rhythm and symptoms of acute coronary syndrome
- G. J. Mitchell, K. Dodd, D. L. Zvosec, E. Chen, M. A. Hart, J. Marshall, A. A. Smith, J. Suna, L. Cullen, S. W. Smith
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- Journal:
- Canadian Journal of Emergency Medicine / Volume 20 / Issue S1 / May 2018
- Published online by Cambridge University Press:
- 11 May 2018, p. S93
- Print publication:
- May 2018
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Introduction: The ECG diagnosis of acute coronary occlusion (ACO) in the setting of ventricular paced rhythm (VPR) is purported to be impossible. However, VPR has a similar ECG morphology to LBBB. The validated Smith-modified Sgarbossa criteria (MSC) have high sensitivity (Sens) and specificity (Spec) for ACO in LBBB. MSC consist of 1 of the following in 1 lead: concordant ST Elevation (STE) 1 mm, concordant ST depression 1 mm in V1-V3, or ST/S ratio <−0.25 (in leads with 1 mm STE). We hypothesized that the MSC will have higher Sens for diagnosis of ACO in VPR when compared to the original Sgarbossa criteria. We report preliminary findings of the Paced Electrocardiogram Requiring Fast Emergency Coronary Therapy (PERFECT) study Methods: The PERFECT study is a retrospective, multicenter, international investigation of ED patients from 1/2008 - 12/2016 with VPR on the ECG and symptoms suggestive of acute coronary syndrome (e.g. chest pain or shortness of breath). Data from four sites are presented. Acute myocardial infarction (AMI) was defined by the Third Universal Definition of AMI. A blinded cardiologist adjudicated ACO, defined as thrombolysis in myocardial infarction score 0 or 1 on coronary angiography; a pre-defined subgroup of ACO patients with peak cardiac troponin (cTn) >100 times the 99% upper reference limit (URL) of the cTn assay was also analyzed. Another blinded physician measured all ECGs. Statistics were by Mann Whitney U, Chi-square, and McNemars test. Results: The ACO and No-AMI groups consisted of 15 and 79 encounters, respectively. For the ACO and No-AMI groups, median age was 78 [IQR 72-82] vs. 70 [61-75] and 13 (86%) vs. 48 (61%) patients were male. The median peak cTn ratio (cTn/URL) was 260 [33-663] and 0.5 [0-1.3] for ACO vs. no-AMI. The Sens and Spec for the MSC and the original Sgarbossa criteria were 67% (95%CI 39-87) vs. 46% (22-72; p=0.25) and 99% (92-100) vs. 99% (92-100; p=0.5). In pre-defined subgroup analysis of ACO patients with peak cTn >100 times the URL (n=10), the Sens was 90% (54-100) for the MSC vs. 60% (27- 86) for original Sgarbossa criteria (p=0.25). Conclusion: ACO in VPR is an uncommon condition. The MSC showed good Sens for diagnosis of ACO in the presence of VPR, especially among patients with high peak cTn, and Spec was excellent. These methods and results are consistent with studies that have used the MSC to diagnose ACO in LBBB.
Calm Merino ewes have a higher ovulation rate and more multiple pregnancies than nervous ewes
- E. van Lier, K. W. Hart, C. Viñoles, B. Paganoni, D. Blache
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In 1990, two selection lines of Merino sheep were established for low and high behavioural reactivity (calm and nervous temperament) at the University of Western Australia. Breeding records consistently showed that calm ewes weaned 10% to 19% more lambs than the nervous ewes. We hypothesise that calm ewes could have a higher ovulation rate than nervous ewes and/or calm ewes could have a lower rate of embryo mortality than nervous ewes. We tested these hypotheses by comparing the ovulation rate and the rate of embryo mortality between the calm and nervous lines before and after synchronisation and artificial insemination. Merino ewes from the temperament selection lines (calm, n=100; nervous, n=100) were synchronised (early breeding season) for artificial insemination (day 0) (intravaginal sponges containing fluogestone acetate and eCG immediately after sponge withdrawal). On day-17 and 11 ovarian cyclicity and corpora lutea, and on days 30 and 74 pregnancies and embryos/foetuses were determined by ultrasound. Progesterone, insulin and leptin concentrations were determined in blood plasma samples from days 5, 12 and 17. Ovarian cyclicity before and after oestrus synchronisation did not differ between the lines, but ovulation rate did (day-17: calm 1.63; nervous 1.26; P<0.01; day 11: calm 1.83; nervous 1.57; P<0.05). Ovulation rate on day 11 in nervous ewes was higher than on day-17. Loss of embryos by day 30 was high (calm: 71/150; nervous: 68/130); but nervous ewes had a lower proportion (15/47) of multiple pregnancies compared with calm ewes (30/46; P<0.01). Reproductive loss between days 30 and 74 represented 7.3% of the overall loss. Temperament did not affect concentrations of progesterone, but nervous ewes had higher insulin (32.0 pmol/l±1.17 SEM; P=0.013) and lower leptin (1.18 μg/l±0.04 SEM; P=0.002) concentrations than calm ewes (insulin: 27.8 pmol/l±1.17 SEM; leptin: 1.35 μg/l±0.04 SEM). The differences in reproductive outcomes between the calm and nervous ewes were mainly due to a higher ovulation rate in calm ewes. We suggest that reproduction in nervous ewes is compromised by factors leading up to ovulation and conception, or the uterine environment during early pregnancy, that reflect differences in energy utilisation.
Response of Glyphosate-Resistant and Glyphosate-Susceptible Bentgrass (Agrostis spp.) to Postemergence Herbicides
- Stephen E. Hart, Fred Yelverton, Eric K. Nelson, Darren W. Lycan, Gerald M. Henry
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- Journal:
- Weed Technology / Volume 19 / Issue 3 / September 2005
- Published online by Cambridge University Press:
- 20 January 2017, pp. 549-559
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Studies were conducted in the summer and fall of 2001 in North Brunswick, NJ, and Marion County, Oregon, to evaluate the response of glyphosate-resistant and glyphosate-susceptible creeping bentgrass hybrids, colonial bentgrass, redtop, and dryland bentgrass grown as individual plants to postemergence (POST) herbicides. Glyphosate at 1.7 kg ae/ha, glufosinate at 1.7 kg ai/ha, fluazifop-P at 0.3 and 0.4 kg ai/ha, clethodim at 0.3 kg ai/ha, sethoxydim at 0.5 kg ai/ha, and a combination of glyphosate and fluazifop-P were applied 6 wk after planting. Glyphosate provided almost complete control of all susceptible bentgrass species at 4 weeks after treatment (WAT). Glufosinate provided 95% or greater control of all bentgrass species at 4 WAT, but regrowth was observed on all species in the summer experiment in Oregon. Fluazifop-P, clethodim, and sethoxydim provided slower control of bentgrass species, which ranged from 38 to 94% at 4 WAT, depending on species, herbicide, and experimental location. By 8 WAT, fluazifop-P at 0.4 kg/ha applied alone or in combination with glyphosate showed the highest levels of control (>90%) across all bentgrass species. Studies were also conducted in 2002 in the spring and summer in North Carolina to evaluate the response of a mature stand of glyphosate-susceptible ‘Penncross’ creeping bentgrass to POST herbicides. Two applications of glyphosate at 1.7 kg/ha were required to achieve 98% bentgrass control at 8 WAT. Fluazifop-P at 0.4 kg/ha, clethodim at 0.3 kg/ha, and sethoxydim at 0.4 kg/ha exhibited herbicidal activity, but two applications were required to reach (>82%) control of bentgrass at 8 WAT. Two sequential applications of clethodim or the combination of glyphosate and fluazifop-P provided 98% control of bentgrass at 8 WAT. Of the other herbicide treatments evaluated, only atrazine and sulfosulfuron provided (>80%) control at 8 WAT. The results of these studies demonstrate that fluazifop-P, clethodim, and sethoxydim have substantial herbicide activity on bentgrass species and may be viable alternatives to glyphosate for control of glyphosate-resistant creeping bentgrass and related bentgrass species in areas where they are not wanted. Glufosinate, atrazine, and sulfosulfuron also exhibited substantial herbicidal activity on bentgrass, and further research with these herbicides is warranted.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- The Cambridge Dictionary of Philosophy
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- 05 August 2015
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- 27 April 2015, pp ix-xxx
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Oesophageal perforation in a neonate during transoesophageal echocardiography for cardiac surgery
- Jeffrey W. Miller, Catherine K. Hart, Christopher J. Statile
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- Cardiology in the Young / Volume 25 / Issue 5 / June 2015
- Published online by Cambridge University Press:
- 09 September 2014, pp. 1015-1018
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Oesophageal perforation is a rarely reported complication of transoesophageal echocardiography in infants. This case involves a 3.1-kg neonate with Trisomy 21, atrioventricular septal defect, and hypoplastic aortic arch undergoing aortic arch advancement and pulmonary artery banding. A paediatric transoesophageal echocardiography probe was placed intraoperatively causing a contained false passage from the oesophagus below the cricopharyngeus muscle with extension into the left posterior mediastinum. The perforation healed within 2 weeks without permanent sequelae after conservative medical management.
Contributors
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- By W. P. Aspinall, P. Bates, K. J. Beven, P. G. Challenor, N. A. Chapman, R. M. Cooke, S. E. Cornell, H. S. Crosweller, T. L. Edwards, J. Freer, J. Hall, A. Hart, G. L. Hickey, B. E. Hill, L. J. Hill, T. K. Hincks, E. A. Holcombe, M. S. Jackson, M. Kern, D. J. Kerridge, T. J. Lynham, B. D. Malamud, J. Neal, J. Pooley, J. C. Rougier, G. Schumann, R. S. J. Sparks, C. A. Taylor, J. Wilmshurst, M. J. Wooster
- Edited by Jonathan Rougier, University of Bristol, Steve Sparks, University of Bristol, Lisa J. Hill, University of Bristol
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- Risk and Uncertainty Assessment for Natural Hazards
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- 05 March 2013
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- 21 February 2013, pp vii-x
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Contributors
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- By C. Alan Anderson, Celso Arango, David B. Arciniegas, Igor Bombin, Robert W. Buchanan, C. Robert Cloninger, Joshua Cosman, C. Munro Cullum, Felipe DeBrigard, Steven L. Dubovsky, Robert Feinstein, Lynne Fenton, Christopher M. Filley, Laura A. Flashman, Morris Freedman, Oliver Freudenreich, Kimberly L. Frey, Lauren C. Frey, Kelly S. Giovanello, Deborah A. Hall, John Hart, Kenneth M. Heilman, Katherine L. Howard, Robin A. Hurley, Daniel I. Kaufer, Sita Kedia, James P. Kelly, B. K. Kleinschmidt-DeMasters, Benzi M. Kluger, David G. Lichter, Deborah M. Little, Deborah M. Lucas, Thomas W. McAllister, Mario F. Mendez, Doron Merims, Steven G. Ojemann, Fred Ovsiew, Brian D. Power, Bruce H. Price, Gila Z. Reckess, Martin L. Reite, Matthew Rizzo, Donald C. Rojas, Michael Henry Rosenbloom, Elliott D. Ross, Jeremy D. Schmahmann, Stuart A. Schneck, Jonathan M. Silver, Mark C. Spitz, Sergio E. Starkstein, Katherine H. Taber, Robert L. Trestman, Hal S. Wortzel
- Edited by David B. Arciniegas, C. Alan Anderson, Christopher M. Filley
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- Behavioral Neurology & Neuropsychiatry
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- 05 February 2013
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- 24 January 2013, pp vii-x
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- By Thomas M. Achenbach, Marc H. Bornstein, W. Thomas Boyce, Robert H. Bradley, Kelly Bridges, Jeanne Brooks-Gunn, Brenda K. Bryant, Sandra L. Calvert, Scott Coltrane, E. Mark Cummings, Stacey B. Daughters, Cindy DeCoste, Marc de Rosnay, Jacquelynne S. Eccles, Hadas Eidelman, Ruth Feldman, Peter Fonagy, Walter S. Gilliam, Andrea L. Gold, Elena L. Grigorenko, Sara Harkness, Sybil L. Hart, Jessica S. Henry, Erika Hoff, Tom Hollenstein, Stephanie M. Jones, Julia Kim-Cohen, Pamela K. Klebanov, Brett Laursen, Mary J. Levitt, Alicia F. Lieberman, Shoon Lio, Jessica F. Magidson, Ann S. Masten, David L. Molfese, Peter J. Molfese, Lynne Murray, Jelena Obradović, Lauren M. Papp, Ross D. Parke, Yaacov Petscher, Aelesia Pisciella, Aliza W. Pressman, Sarah Rabbitt, Craig T. Ramey, Sharon Landesman Ramey, Jessica M. Richards, Robert W. Roeser, Thomas J. Schofield, Ronald Seifer, Anne Shaffer, Michelle Sleed, Laura Stout Sosinsky, Nancy E. Suchman, Charles M. Super, Louis Tuthill, Patricia Van Horn, Eric Vega, Sarah Ward, Monica Yudron
- Edited by Linda Mayes, Yale University, Connecticut, Michael Lewis
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- The Cambridge Handbook of Environment in Human Development
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- 05 October 2012
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- 27 August 2012, pp ix-xvi
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- By Mohamed Aboulghar, Ahmed Abou-Setta, Mary E. Abusief, G. David Adamson, R. J. Aitken, Hesham Al-Inany, Baris Ata, Hamdy Azab, Adam Balen, David H. Barad, Pedro N. Barri, C. Blockeel, Giuseppe Botta, Mark Bowman, Chris Brewer, Dominique M. Butawan, Sandra A. Carson, Hai Ying Chen, Anne Clark, Buenaventura Coroleu, S. Das, C. Dechanet, H. Déchaud, Cora de Klerk, Sheryl de Lacey, S. Deutsch-Bringer, P. Devroey, Didier Dewailly, Hakan E. Duran, Walid El Sherbiny, Tarek El-Toukhy, Johannes L. H. Evers, Cynthia Farquhar, Rodney D. Franklin, Juan A. Garcia-Velasco, David K. Gardner, Norbert Gleicher, Gedis Grudzinskas, Roger Hart, B Hédon, Colin M. Howles, Jack Yu Jen Huang, N. P. Johnson, Hey-Joo Kang, Gab Kovacs, Ben Kroon, Anver Kuliev, William H. Kutteh, Nick Macklon, Ragaa Mansour, Lamiya Mohiyiddeen, Lisa J. Moran, David Mortimer, Sharon T. Mortimer, Luciano G. Nardo, Robert J. Norman, Willem Ombelet, Luk Rombauts, Zev Rosenwaks, Francisco J. Ruiz Flores, Anthony J. Rutherford, Gavin Sacks, Denny Sakkas, M. W. Seif, Ayse Seyhan, Caroline Smith, Kate Stern, Elizabeth A. Sullivan, Sesh Kamal Sunkara, Seang Lin Tan, Mohamed Taranissi, Kelton P. Tremellen, Wendy S. Vitek, V. Vloeberghs, Bradley J. Van Voorhis, S. F. van Voorst, Amr Wahba, Yueping A. Wang, Klaus E. Wiemer
- Edited by Gab Kovacs, Monash University, Victoria
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- How to Improve your ART Success Rates
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- 05 July 2011
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- 30 June 2011, pp viii-xii
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The value of antiseptics as prophylactic applications to recent wounds
- J. Gordon, J. W. McLeod, Anna Mayr-Harting, J. W. Orr, K. Zinnemann
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- Journal of Hygiene / Volume 45 / Issue 3 / August 1947
- Published online by Cambridge University Press:
- 15 May 2009, pp. 297-306
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There have been groups of observers both in this country and in Germany who have been entirely sceptical about the value of the prophylactic application of antiseptics to wounds and who seem to incline to the opinion that such medication is likely to be more harmful than useful; e.g. Colebrook in a special report to the Medical Research Council (1928) stated that ‘the ordinary “antiseptics” have a higher affinity for the leucocytes than for the microbes, and by combining with the former forfeit their microbicidal potential’. Further, he stated that with the exception of optochin and neosalvarsan, substances which have been tried as antiseptics are so rapidly fixed on serum proteins, blood cells, and the fixed tissues, that they fail to impart bactericidal power to the serum. Fleming (1924, 1931) in a number of ingenious experiments showed that injury to leucocytes is the most likely outcome of antiseptic applications to wounds, and has argued that they are more likely to be harmful than useful for that reaon; later (1938), he pointed out the superiority of the sulphonamides to the older antiseptics as tested by his ‘slide cell’ technique and in penicillin he has discovered an antiseptic which in respect of a high ratio of bactericidal potency to its toxicity to mammalian tissues approaches the ideal. This has given the clinical results which would be expected on theoretical grounds. There are, however, limitations to the use of penicillin as a general prophylactic antiseptic application which depend on (a) its failure to destroy some types of bacteria which cause suppuration, (b) its relative lability, (c) its present cost. There is therefore ground for further careful assessment of the best prophylactic antiseptic. Fleming (1940) has in fact admitted that there may be a place for proflavine in the interim dressing of wounds pending surgical treatment. The German opinion on the question of the prophylactic use of antiseptics seems to have been considerably influenced by the observations of Schimmelbusch, who had demonstrated that mice inoculated on a scarified area of the tail with anthrax bacilli could not be saved when the tail was amputated at a point proximal to the site of inoculation even 10 min. after the wound had been infected. It was concluded on this account that the penetration of bacteria from a wound into the deeper tissues was so rapid that local treatment of the wound was obviously futile. Schiemann & Wreschner (1922) and Weise (1922), however, who record these observations of Schimmelbusch, made similar observations with streptococci but showed that with this micro-organism not only tail amputation but also local application of antiseptics was often successful in saving mice so infected. They did not dispute the rapid penetration of the bacteria but concluded that in the case of the streptococcus the body could deal with limited numbers of these micro-organisms, if the local lesions from which they were reaching the general circulation were eliminated. Further, Browning (1943) in a discussion of the antiseptic action of the amino acridine compounds made an extensive survey of the literature on the influence of these substances on leucocytes and concluded that in view of the wide variations in results the particular technique adopted must be an important factor. Hence he suggests there is need for much caution in accepting such results as an indication of what will actually happen in the animal body.
Use of isozymes as chromosome markers in the isolation and characterization of wheat-barley chromosome addition lines
- Gary E. Hart, A. K. M. R. Islam, K. W. Shepherd
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- Genetical Research / Volume 36 / Issue 3 / December 1980
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- 14 April 2009, pp. 311-325
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The alcohol dehydrogenase (ADH), glutamic oxaloacetic transaminase (GOT), aminopeptidase (AMP), endopeptidase (EP), and esterase (EST) zymogram phenotypes of Chinese Spring wheat, Betzes barley, Chinese Spring-Betzes heptaploids, and a number of presumptive Betzes chromosome additions to Chinese Spring were determined. It was found that four disomic chromosome addition lines could be distinguished from one another and from the other three possible lines on the basis of the zymogram phenotypes of these isozymes.
The structural gene Adh-H1 was located in Betzes chromosome 4, the genes Got-H2 and Amp-H1 in chromosome 6, and the gene Ep-H1 in chromosome 1. These gene locations provide evidence of homoeology between Betzes chromosomes 4, 6, and 1 and the Chinese Spring chromosomes of homoeologous groups 4, 6, and 7, respectively.
Biochemistry and molecular genetics of Leishmania glucose transporters
- C. K. Langford, R. J. S. Burchmore, D. T. Hart, W. Wagner, S. M. Landfear
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- Journal:
- Parasitology / Volume 108 / Issue S1 / March 1994
- Published online by Cambridge University Press:
- 06 April 2009, pp. S73-S83
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Glucose is utilized as a significant source of metabolic energy by Leishmania parasites. This sugar is accumulated by the parasite via a specific carrier-mediated transport system located in the parasite membrane. Parasites may also contain another transporter that shuttles glucose between the cytoplasm and the glycosome, a membrane-bound organelle where the early steps of glycolysis occur. The transport systems of both the insect stage promastigotes and the intracellular amastigotes have been characterized and shown to have kinetic properties that are consistent with the different physio-logical environments of the insect gut and the macrophage phagolysosome. Several genes have been cloned from Leishmania species which encode proteins with substantial sequence similarity to glucose transporters from mammals and lower eukaryotes. Two of these genes are expressed preferentially in the promastigote stage of the life cycle, where glucose is more readily available and more rapidly transported and metabolized than in the intracellular amastigotes. One of these two developmentally-regulated genes has been functionally expressed in Xenopus oocytes and shown to encode a glucose transporter. A third gene encodes a protein that is also a member of the glucose transporter family on the basis of sequence similarity and proposed secondary structure. However, the significant differences between this protein and the other two suggest that it is likely to transport a different substrate. Functional expression will be required to define the specific biochemical role of each gene within the parasite.
Immunolocalization Of Phosphodiesterase Isoenzymes In Rat Tissues Using Confocal Microscopy
- Beverly E. Maleeff, Rosanna C. Mirabile, Timothy K. Hart, Heath C. Thomas, Lester W. Schwartz, Stephen J. Newsholme
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- Journal:
- Microscopy and Microanalysis / Volume 8 / Issue S02 / August 2002
- Published online by Cambridge University Press:
- 01 August 2002, pp. 138-139
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- August 2002
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Aqueous Durability of Titanate Ceramics Designed to Immobilize Excess Plutonium
- K. P. Hart, Y. Zhang, E. Loi, Z. Aly, M. W. A. Stewart, A. Brownscombe, B. B. Ebbinghaus, W. Bourcier
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- Journal:
- MRS Online Proceedings Library Archive / Volume 608 / 1999
- Published online by Cambridge University Press:
- 10 February 2011, 353
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- 1999
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Aqueous durability has been assessed for fourteen pyrochlore- and zirconolite-rich titanate waste forms designed for the immobilisation of excess Pu. The ceramics used in this study contained about 12 wt% Pu and about 15 wt% of Hf and Gd oxides as neutron absorbers and were fabricated by cold-pressing and sintering or hot isostatic pressing.
Total release rates (i.e. unfiltered solution + vessel wall inventory) have been measured withthe MCC-1 test method at 90 °C in deionised water. For all samples, 7-day release rates of Pu are between 4 × 10−5 and about 10−3 g.m−2.d−1, reducing to between about 8 × 10−6 and 3 × 10−5 g.m−2.d−1after more than 300 days of leaching. Release rates of U from the baseline ceramic were found to decrease to values between 6 × 10−4 and 1 × 10−5 g.m−2.d−1after 200 days. Hf leach rates were generally < 5 × 10−6 g.m−2.d−l after more than 7 days. Further, the addition of several % of chemical impurities to the baseline sintered formulations was found to reduce U and Gd releases by about a factor of 10 after 200 days.
Leaching Behavior of Zirconolite-Rich Synroc Used to Immobilize High-Fired Plutonium Oxide
- K. P. Hart, E. R. Vance, M. W. A. Stewart, J. Weir, M. L. Carter, M. Hambley, A. Brownscombe, R. A. Day, S. Leung, C. J. Ball, B. Ebbinghaus, L. Gray, T. Kan
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- Journal:
- MRS Online Proceedings Library Archive / Volume 506 / 1997
- Published online by Cambridge University Press:
- 10 February 2011, 161
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- 1997
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This study reports on the use of zirconolite-rich Synroc to demonstrate the safe immobilisation of ‘high-fired’ Pu02. The zirconolite-rich Synroc used in this study was prepared by adding 13 wt% Pu with equimolar amounts of Gd and Hf, relative to Pu, as neutron absorbers. The incorporation of the Pu and neutron absorbers has been studied microstructurally as well as by longer-term leach testing. This work has shown that the sintered ceramic can immobilise 13 wt% of Pu with almost complete incorporation of the Pu (≃ 98%) into the zirconolite phase. Durability studies have shown that under a wide range of leaching conditions there is no major separation of the Pu and neutron absorbers, with the majority of these elements either remaining in the matrix or leaching at low (< 10−4 g m−2 d−1) and comparable rates from the waste form.