33 results
Long-term effects of electroconvulsive therapy on brain structure in major depression
- Tiana Borgers, Verena Enneking, Melissa Klug, Jasper Garbe, Hannah Meinert, Marius Wulle, Philine König, Esther Zwiky, Rebekka Herrmann, Janine Selle, Katharina Dohm, Anna Kraus, Dominik Grotegerd, Jonathan Repple, Nils Opel, Elisabeth J. Leehr, Marius Gruber, Janik Goltermann, Susanne Meinert, Jochen Bauer, Walter Heindel, Erhan Kavakbasi, Bernhard T. Baune, Udo Dannlowski, Ronny Redlich
-
- Journal:
- Psychological Medicine / Volume 54 / Issue 5 / April 2024
- Published online by Cambridge University Press:
- 08 September 2023, pp. 940-950
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
Background
Magnetic resonance imaging (MRI) studies on major depressive disorder (MDD) have predominantly found short-term electroconvulsive therapy (ECT)-related gray matter volume (GMV) increases, but research on the long-term stability of such changes is missing. Our aim was to investigate long-term GMV changes over a 2-year period after ECT administration and their associations with clinical outcome.
MethodsIn this nonrandomized longitudinal study, patients with MDD undergoing ECT (n = 17) are assessed three times by structural MRI: Before ECT (t0), after ECT (t1) and 2 years later (t2). A healthy (n = 21) and MDD non-ECT (n = 33) control group are also measured three times within an equivalent time interval. A 3(group) × 3(time) ANOVA on whole-brain level and correlation analyses with clinical outcome variables is performed.
ResultsAnalyses yield a significant group × time interaction (pFWE < 0.001) resulting from significant volume increases from t0 to t1 and decreases from t1 to t2 in the ECT group, e.g., in limbic areas. There are no effects of time in both control groups. Volume increases from t0 to t1 correlate with immediate and delayed symptom increase, while volume decreases from t1 to t2 correlate with long-term depressive outcome (all p ⩽ 0.049).
ConclusionsVolume increases induced by ECT appear to be a transient phenomenon as volume strongly decreased 2 years after ECT. Short-term volume increases are associated with less symptom improvement suggesting that the antidepressant effect of ECT is not due to volume changes. Larger volume decreases are associated with poorer long-term outcome highlighting the interplay between disease progression and structural changes.
Evolution and Associated Factors of Hand Hygiene Compliance in the Surgical Areas of a Tertiary-Care Hospital
- Natividad Algado-Sellés, Paula Gras-Valentí, Juan Gabriel Mora-Muriel, Pablo Chico-Sánchez, Marina Fuster-Pérez, Sandra Canovas-Javega, Cesar O. Villanueva-Ruiz, Edith Leutscher-Vasen, Ana S. Lameiras-Azevedo, Maria Hernandez-Maldonado, Natali J. Jimenez-Sepulveda, Jose Sanchez-Paya
-
- Journal:
- Infection Control & Hospital Epidemiology / Volume 41 / Issue S1 / October 2020
- Published online by Cambridge University Press:
- 02 November 2020, pp. s231-s232
- Print publication:
- October 2020
-
- Article
-
- You have access Access
- Export citation
-
Background: Hand hygiene (HH) is the most important measure for preventing healthcare-associated infections. The objective is to gain insight into the evolution of the degree of compliance with recommendations (DCR) on HH and its associated factors in the surgical areas of a tertiary-care hospital. Methods: This observational, cross-sectional study, was repeated over time, with direct observation of the DCR on HH during the daily activity of healthcare workers in surgical areas: general surgery, urology, vascular surgery, traumatology, neurosurgery, thoracic surgery, heart surgery, pediatric surgery, otorhinolaryngology, gynecology and obstetrics, ophthalmology. Over 14 years (from 2005 to 2018), 15,946 HH opportunities were registered, together with different additional variables (age, sex, professional position, surgical area ). The 2 test was used to study the association and the crude, and adjusted odds ratios were used to quantify its magnitude. Results: The DCR on HH in surgical areas was 49.7% (95% CI, 48.9%–50.5%), and in the group of nonsurgical areas it was 53.4% (95% CI, 53.1%–54.1%). The area with the highest degree of compliance was urology (56.7%; 95% CI, 53.9%–59.6%), and the area with the lowest degree of compliance was traumatology (43.3%; 95% CI, 40.4%–46.2%). Some associated factors were the indications after an activity has been performed (58.6%; aOR, 2.7; 95% CI, 2.5–2.9) and the availability of pocket-size alcohol-based disinfectant (63.8%; aOR, 2.4; 95% CI, 2.2–2.5). Conclusions: The DCR on HH in surgical areas is lower than in other hospital areas, and there is still some margin for improvement. We have identified some modifiable factors that have an independent association with HH compliance in surgical areas. Focusing on them will increase compliance with HH with the ultimate goal of reducing healthcare-associated infections.
Funding: None
Disclosures: None
Effectiveness of Annual Flu Vaccination Until Week Four of the 2019–2020 Season
- Pablo Chico-Sánchez, Juan Gabriel Mora-Muriel, Paula Gras-Valentí, Natali J. Jimenez-Sepulveda, Natividad Algado-Sellés, Isel Gomez-Sotero, Victor Soler, Ana Esclapez-Martinez, Sandra Canovas-Javega, Jose Sanchez-Paya
-
- Journal:
- Infection Control & Hospital Epidemiology / Volume 41 / Issue S1 / October 2020
- Published online by Cambridge University Press:
- 02 November 2020, pp. s84-s85
- Print publication:
- October 2020
-
- Article
-
- You have access Access
- Export citation
-
Background: Annual flu vaccination is the most effective way to prevent the disease and its complications. Vaccine effectiveness (EV) varies from season to season, requiring annual re-evaluation. The objective of this study was to estimate the preliminary effectiveness of the influenza vaccine until epidemiological week 4 of the 2019–2020 season, in patients admitted to a tertiary-level hospital. Method: We conducted a case-control study at University General Hospital, Alicante, Spain, during the 2019–2020 season. We included all patients hospitalized with influenza confirmed by laboratory test (ie, PCR positive for influenza) during the period between epidemiological week 40 of 2019 and epidemiological week 4 of 2020. These were considered cases, and those with clinical suspicion of influenza and negative RT-PCR were considered controls. Vaccination coverage was calculated in cases and in controls, determining the odds ratio. We calculated the vaccine effectiveness (VE) and its 95% confidence interval using the following formula: VE = (1 − odds ratio) ×100. Result: We included 545 patients: 61 cases and 484 controls. The overall EV for influenza cases prevention was 40.7% (95% CI, −17.1 to 70.1), and for those >1 year of age, the overall EV was 56.9% (95% CI, 13.9–78.5). Conclusion: The 2019–2020 Influenza vaccine was effective in preventing influenza cases in patients admitted up to week 4 of the 2019–2020 season. These results are preliminary and may vary; they should be re-evaluated at the end of the season.
Funding: None
Disclosures: None
Prioritizing Communication About Radiation Risk Reduction in the United States: Results from a Multi-criteria Decision Analysis
- Rennie W. Ferguson, Daniel J. Barnett, Ryan David Kennedy, Tara Kirk Sell, Jessica S. Wieder, Ernst W. Spannhake
-
- Journal:
- Disaster Medicine and Public Health Preparedness / Volume 15 / Issue 6 / December 2021
- Published online by Cambridge University Press:
- 23 June 2020, pp. 718-726
-
- Article
- Export citation
-
Objectives:
The lack of radiation knowledge among the general public continues to be a challenge for building communities prepared for radiological emergencies. This study applied a multi-criteria decision analysis (MCDA) to the results of an expert survey to identify priority risk reduction messages and challenges to increasing community radiological emergency preparedness.
Methods:Professionals with expertise in radiological emergency preparedness, state/local health and emergency management officials, and journalists/journalism academics were surveyed following a purposive sampling methodology. An MCDA was used to weight criteria of importance in a radiological emergency, and the weighted criteria were applied to topics such as sheltering-in-place, decontamination, and use of potassium iodide. Results were reviewed by respondent group and in aggregate.
Results:Sheltering-in-place and evacuation plans were identified as the most important risk reduction measures to communicate to the public. Possible communication challenges during a radiological emergency included access to accurate information; low levels of public trust; public knowledge about radiation; and communications infrastructure failures.
Conclusions:Future assessments for community readiness for a radiological emergency should include questions about sheltering-in-place and evacuation plans to inform risk communication.
P.070 Thrombolysis without large vessel occlusion in a child with acute arterial ischemic stroke
- IE Hanes, SL Orr, J Davila, A Kirton, E Sell
-
- Journal:
- Canadian Journal of Neurological Sciences / Volume 46 / Issue s1 / June 2019
- Published online by Cambridge University Press:
- 05 June 2019, p. S33
-
- Article
-
- You have access Access
- Export citation
-
Background: Stroke is a rare neurological disease in children, with an annual incidence of 2 - 13/100,000 children per year. Pediatric stroke is associated with significant morbidity and mortality lasting many decades. Diagnosis of pediatric stroke is challenging and often delayed, limiting options for acute intervention, and the pharmacological and mechanical recanalization strategies that have revolutionized adult stroke remain undefined in children. Clinicians are left to draw conclusions from other retrospective cohort studies or case reports and extrapolate adult guidelines to the pediatric population. The TIPS trial eligibility criteria are often used in clinical practice, despite not being validated for this purpose. We present here the case of a healthy 14 year old male who was treated with intravenous tissue plasminogen activator (IV tPA) for a presumed arterial ischemic stroke without large vessel occlusion on neuroimaging. Methods: Retrospective chart review Results: Not applicable Conclusions: Following the administration of IV tPA, the patient made a full recovery. While we do not recommend the routine use of IV tPA for treatment of presumed large vessel or small vessel in children, we suggest that the decision to proceed with IV tPA be considered on a case-by-case basis.
P.044 Quality of life in children with epilepsy treated with the low glycemic index diet – a pilot study
- S Boles, R Webster, S Parnel, J Murray, S Ieradi, E Sell, D Pohl
-
- Journal:
- Canadian Journal of Neurological Sciences / Volume 46 / Issue s1 / June 2019
- Published online by Cambridge University Press:
- 05 June 2019, p. S25
-
- Article
-
- You have access Access
- Export citation
-
Background: The classic ketogenic diet is the main non-pharmacological treatment for refractory epilepsy; however, adherence is often challenging. The low glycemic index diet (LGID) is less strict, almost equally effective, and associated with improved adherence. Little is known about the quality of life of children treated with LGID. The objective of this study was to explore changes in the quality of life of children with epilepsy transitioning to the LGID. Methods: Patients on LGID and their parents filled out Pediatric Quality of Life Epilepsy Module questionnaires; one while being on the LGID, and one retrospectively for the time prior to starting the LGID. Results: Data was collected from five children ages 3-13 and their parents. Complete seizure control was seen in two children, >50% seizure reduction in one, and no change in two children. Parental reported quality of life while on the LGID increased with two participants but decreased in all child self reports. Conclusions: Although the LGID led to improved seizure control in three out of five patients, the child-reported quality of life decreased in all children. Larger prospective studies are warranted to reliably assess the impact of the LGID on the quality of life in children with epilepsy.
The X-ray binary populations of M81 and M82
- Paul H. Sell, Andreas Zezas, Stephen J. Williams, Jeff J. Andrews, Kosmas Gazeas, John S. Gallagher, Andrew Ptak
-
- Journal:
- Proceedings of the International Astronomical Union / Volume 14 / Issue S346 / August 2018
- Published online by Cambridge University Press:
- 30 December 2019, pp. 344-349
- Print publication:
- August 2018
-
- Article
-
- You have access Access
- Export citation
-
We use deep Chandra and HST data to uniquely classify the X-ray binary (XRB) populations in M81 on the basis of their donor stars and local stellar populations (into early-type main sequence, yellow giant, supergiant, low-mass, and globular cluster). First, we find that more massive, redder, and denser globular clusters are more likely to be associated with XRBs. Second, we find that the high-mass XRBs (HMXBs) overall have a steeper X-ray luminosity function (XLF) than the canonical star-forming galaxy XLF, though there is some evidence of variations in the slopes of the sub-populations. On the other hand, the XLF of the prototypical starburst M82 is described by the canonical powerlaw (αcum ∼ 0.6) down to LX ∼ 1036 erg s−1. We attribute variations in XLF slopes to different mass transfer modes (Roche-lobe overflow versus wind-fed systems).
Hurd Peninsula glaciers, Livingston Island, Antarctica, as indicators of regional warming: ice-volume changes during the period 1956–2000
- C. Molina, F.J. Navarro, J. Calvet, D. García-Sellés, J.J. Lapazaran
-
- Journal:
- Annals of Glaciology / Volume 46 / 2007
- Published online by Cambridge University Press:
- 14 September 2017, pp. 43-49
-
- Article
-
- You have access Access
- HTML
- Export citation
-
Johnsons and Hurd Glaciers are the two main glacier units of Hurd Peninsula ice cap, Livingston Island, South Shetland Islands, Antarctica. They presently cover an area of about 10 km2. Johnsons is a tidewater glacier, while Hurd Glacier ends on emerged land. In this paper, we estimate the changes in ice volume during the period 1956–2000, and compare them with the regional meteorological records. The volume-change estimates are based on the comparison of digital terrain models for the glacier surface, constructed from aerial photographs taken by the British Antarctic Survey in 1956 and from our geodetic measurements in 1999/2000. The total volume estimates are based on an ice-thickness map constructed from radio-echo sounding profiles (18–25 MHz) done in 1999–2001, showing maximum ice thickness of about 200 m. We estimate the changes in ice volume during the period 1956–2000 to be –0.108±0.048km3, which represents a 10.0±4.5% decrease from the 1956 total volume of 1.076±0.055km3 and is equivalent to an average annual mass balance of –0.23±0.10mw.e. during 1956–2000. Ice-thickness changes range from –40 to +20 m, averaging –5.5±4.4 m. Most areas show ice thinning; the thickening is limited to a small area within Johnsons Glacier. All glacier fronts, except Johnsons’ calving front, show retreat. These changes are consistent with the regional meteorological records for mean summer temperature, which show a trend of +0.023±0.005˚Ca–1 during the period 1956–2000.
Growth performance, nutrient utilisation and carcass composition respond to dietary protein concentrations in broiler chickens but responses are modified by dietary lipid levels
- Sonia Y. Liu, Peter H. Selle, David Raubenheimer, Rob M. Gous, Peter V. Chrystal, David J. Cadogan, Stephen J. Simpson, Aaron J. Cowieson
-
- Journal:
- British Journal of Nutrition / Volume 118 / Issue 4 / 28 August 2017
- Published online by Cambridge University Press:
- 06 September 2017, pp. 250-262
- Print publication:
- 28 August 2017
-
- Article
-
- You have access Access
- HTML
- Export citation
-
A total of ten experimental diets with protein concentrations ranging from 154 to 400 g/kg and two lipid levels (46 and 85 g/kg) with identical energy densities were offered to 240 male Ross 308 broilers from 7 to 28 d post-hatch. Growth performance was monitored and nutrient utilisation (apparent metabolisable energy (AME), N-corrected AME (AMEn), AME daily intake, AME:gross energy ratios, N retention) was determined. The weight gain response of broiler chickens to dietary protein concentrations in diets containing high and low lipid levels was diverse, with the relevant quadratic regressions being significantly different (P<0·05). With low lipid levels, the predicted maximum weight gain of 1809 g/bird equated to 342 g/kg dietary protein, whereas, for high lipid levels the predicted maximum weight gain of 1694 g/bird equated to 281 g/kg dietary protein. AME was linearly correlated with dietary protein concentration but regressions in diets with different lipid content were not significantly different (P>0·05). AMEn was also linearly (P<0·0001) increased with dietary protein concentrations but regressions in diets with low and high lipid content were significantly different (P<0·03). Carcass protein content increased linearly with dietary protein content in diets containing high lipid concentrations (r 0·933, P<0·0001); by contrast, this relationship was quadratic (R2=0·93, P<0·0001) in diets with low lipid levels. In conclusion, predictably, the effects of dietary protein concentrations on broiler performance were profound; however, the impact of dietary protein on performance in broiler chickens was modified by dietary lipid concentrations.
A field method for avalanche danger-level verification
- A. Cagnati, M. Valt, G. Soratroi, J. Gavaldà, C. G. SelléS
-
- Journal:
- Annals of Glaciology / Volume 26 / 1998
- Published online by Cambridge University Press:
- 20 January 2017, pp. 343-346
-
- Article
-
- You have access Access
- HTML
- Export citation
-
Even though the danger-level verification indicated in a bulletin should be a priority aim of avalanche-forecast services, there are no easily applicable verification methods available today. The main difficulty lies in the fact that avalanche observation is no longer sufficient. Therefore, it is necessary to verify the actual condition of the snow-pack stability, particularly concerning low danger levels. This work introduces a procedure for “a posteriori” field verification of danger level, both in space and time (24–72 hours). The method is based on the following elements: avalanche-activity survey, observation of cross-country skiers’ activity, snow profiles and “Rutschblock” tests. These elements, relating both to time and the examination zone, are combined to provide an objective danger degree according to the European avalanche-danger scale. The method was used experimentally in the winter of 1993–94 in the Dolomites and subsequently, in the winter of 1995–96 in the Catalan Pyrenees. As far as 24 hour forecasts are concerned, the method has shown a forecast reliability of 93% in the Dolomites and 76% in the Catalan Pyrenees, while 48 hour forecasts have given values of 89% and 64%, respectively. The lower degree of forecast reliability in the Catalan Pyrenees is accounted for by the unusual weather conditions of winter 1995–96, which was very snowy and characterized by few foreseeable avalanche conditions. The practical application of the proposed verification method has given encouraging results, thus allowing experts to find the main errors in order to improve future forecasts. However, simpler survey procedures are necessary in order to operate on a regional scale. The method is suitable for further development relating to verification of both degree of danger and danger localization.
An assessment of the influence of macronutrients on growth performance and nutrient utilisation in broiler chickens by nutritional geometry
- Sonia Y. Liu, Peter H. Selle, David Raubenheimer, David J. Cadogan, Stephen J. Simpson, Aaron J. Cowieson
-
- Journal:
- British Journal of Nutrition / Volume 116 / Issue 12 / 28 December 2016
- Published online by Cambridge University Press:
- 16 January 2017, pp. 2129-2138
- Print publication:
- 28 December 2016
-
- Article
-
- You have access Access
- HTML
- Export citation
-
The right-angled triangle mixture experiment was designed to include fourteen diets with different concentrations of starch, protein and lipid. Experimental diets were offered to male Ross 308 broiler chickens from 10 to 23 d after hatching, and response curves and surfaces were generated to illustrate the influence of macronutrients on growth performance and nutrient utilisations. Despite the primary function of macronutrients, especially protein, may not be providing energy, macronutrients were expressed as energy derived from starch, protein and fat for statistical purposes in the mixture design. Energy derived from lipid had a greater impact on feed intake than energy derived from starch and protein. When we compared the influence of starch and protein on feed intake, ‘equal distance rule’ was observed, which means the animal consumes feed to the point on its respective nutritional rails where the shortage of starch exactly equals the surplus of consumed protein. Increasing the protein-derived energy intake increased weight gain in broiler chickens, whereas energy intake derived from starch and lipid had little impact on weight gain. Feed conversion ratio (FCR) may be reduced by either increasing protein energy intake or decreasing starch energy intake. As the slope of the contours was less than 1, the influence of starch energy intakes on FCR exceeded that of protein energy intakes. In conclusion, energy derived from protein is more important than non-protein energy in terms of weight gain, and a balance between protein and energy supplies is required for efficient muscle protein deposition.
Pharmacological treatment of bipolar depression
- Gustavo H. Vázquez, Leonardo Tondo, Juan Undurraga, Rodolfo Zaratiegui, Valerio Selle, Ross J. Baldessarini
-
- Journal:
- Advances in Psychiatric Treatment / Volume 20 / Issue 3 / May 2014
- Published online by Cambridge University Press:
- 02 January 2018, pp. 193-201
- Print publication:
- May 2014
-
- Article
-
- You have access Access
- HTML
- Export citation
-
Bipolar depression remains a major challenge for psychiatric therapeutics. It is associated with disability and excess mortality, and accounts for three-quarters of the time spent in morbid states by treated patients with bipolar disorder. Major limitations of research on the treatment of depression in bipolar disorder include a paucity of short-term and lack of long-term trials, probably reflecting concern about inducing mania. In addition, polytherapy with multiple drugs appears to be widespread, but it is virtually untested for efficacy and safety. Here, we summarise the evidence concerning efficacy of treatment of bipolar depression with antidepressants, mood-stabilising anticonvulsants, lithium and second-generation antipsychotics.
LEARNING OBJECTIVES• Gain critical appreciation of the paucity of research on the treatment of bipolar depression.
• Rationally balance the benefits and risks of using antidepressants in patients with bipolar disorder.
• Assess the evidence supporting a range of research-based treatment options for bipolar depression.
Foreword
- W. C. R. Watson
-
- Book:
- Handbook of the Rubi of Great Britain and Ireland
- Published online:
- 05 June 2016
- Print publication:
- 19 September 2013, pp v-vi
-
- Chapter
- Export citation
-
Summary
WHEN the author died in 1954, he had nearly completed his work and only a few trivial emendations and additions have been made. All the descriptions were complete with the exception of the section Appendiculati which has been prepared from his account of the series and subseries. In the analytical key there was no method of arriving at the sections, subsections, series and subseries. As it seemed undesirable that the text should have to be consulted to arrive at the appropriate group, the group descriptions have been extracted from the text and incorporated into the key. Under the nomenclature only dates had been quoted, but it seemed desirable to have full references. This has been done with the exception of the group headings. No authority or reference for the group headings, many of which are new or have new status, had been given by the author, and it has only proved practicable to give basonym authorities. All new names and combinations have been published separately in a paper in Watsonia. All the type material from Watson's herbarium has been deposited at the British Museum (Nat. Hist.).
It is believed that the author would have wished to thank Miss Ruth M. Ball and Mr A. W. Darnell for drawing the illustrations; the authorities of the British Museum (Nat. Hist.) and the South London Botanical Institute for the use of specimens and books; and the many fellow botanists for help received during his life-long study of the genus Rubus, which has resulted in this, his most considerable work.
Contributors
-
- By Artemis Alexiadou, Mark C. Baker, Sjef Barbiers, James P. Blevins, Željko Bošković, Hans Broekhuis, Daniel Büring, Norbert Corver, Jeroen van Craenenbroeck, Stephen Crain, Veneeta Dayal, Marcel den Dikken, Samuel D. Epstein, Robert Frank, Caroline Heycock, Hisatsugu Kitahara, Antje Lahne, Howard Lasnik, Ellen F. Lau, Terje Lohndal, Jason Merchant, Frederick J. Newmeyer, Miki Obata, Maria Polinsky, Gillian Ramchand, Luigi Rizzi, Ken Safir, Ivan A. Sag, T. Daniel Seely, Peter Sells, Jon Sprouse, Rosalind Thornton, Ellen Woolford, Karen Zagona, Hedde Zeijlstra
- Edited by Marcel den Dikken, City University of New York
-
- Book:
- The Cambridge Handbook of Generative Syntax
- Published online:
- 05 August 2013
- Print publication:
- 25 July 2013, pp vii-viii
-
- Chapter
- Export citation
Protein–phytate interactions in pig and poultry nutrition: a reappraisal
- Peter H. Selle, Aaron J. Cowieson, Nathan P. Cowieson, V. Ravindran
-
- Journal:
- Nutrition Research Reviews / Volume 25 / Issue 1 / June 2012
- Published online by Cambridge University Press:
- 06 February 2012, pp. 1-17
-
- Article
-
- You have access Access
- HTML
- Export citation
-
Protein–phytate interactions are fundamental to the detrimental impact of phytate on protein/amino acid availability. The inclusion of exogenous phytase in pig and poultry diets degrades phytate to more innocuous esters and attenuates these negative influences. The objective of the present review is to reappraise the underlying mechanisms of these interactions and reassess their implications in pig and poultry nutrition. Protein digestion appears to be impeded by phytate in the following manner. Binary protein–phytate complexes are formed at pH levels less than the isoelectric point of proteins and complexed proteins are refractory to pepsin digestion. Once the protein isoelectric points are exceeded binary complexes dissociate; however, the isoelectric point of proteins in cereal grains may be sufficiently high to permit these complexes to persist in the small intestine. Ternary protein–phytate complexes are formed at pH levels above the isoelectric point of proteins where a cationic bridge links the protein and phytate moieties. The molecular weights of protein and polypeptides in small-intestinal digesta may be sufficient to allow phytate to bind nutritionally important amounts of protein in ternary complexes. Thus binary and ternary complexes may impede protein digestion and amino acid absorption in the small intestine. Alternatively, phytate may interact with protein indirectly. Myo-inositol hexaphosphate possesses six phosphate anionic moieties (HPO42–) that have strong kosmotropic effects and can stabilise proteins by interacting with the surrounding water medium. Phytate increases mucin secretions into the gut, which increases endogenous amino acid flows as the protein component of mucin remains largely undigested. Phytate promotes the transition of Na+ into the small-intestinal lumen and this suggests that phytate may interfere with glucose and amino acid absorption by compromising Na+-dependent transport systems and the activity of the Na pump (Na+-K+-ATPase). Starch digestion may be depressed by phytate interacting with proteins that are closely associated with starch in the endosperm of cereal grains. While elucidation is required, the impacts of dietary phytate and exogenous phytase on the site, rate and synchrony of glucose and amino acid intestinal uptakes may be of importance to efficient protein deposition. Somewhat paradoxically, the responses to phytase in the majority of amino acid digestibility assays in pigs and poultry are equivocal. A brief consideration of the probable reasons for these inconclusive outcomes is included in this reappraisal.
Contributors
-
- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. Nicholson, George W. E. Nickelsburg, Tatyana Nikolskaya, Damayanthi M. A. Niles, Bertil Nilsson, Nyambura Njoroge, Fidelis Nkomazana, Mary Beth Norton, Christian Nottmeier, Sonene Nyawo, Anthère Nzabatsinda, Edward T. Oakes, Gerald O'Collins, Daniel O'Connell, David W. Odell-Scott, Mercy Amba Oduyoye, Kathleen O'Grady, Oyeronke Olajubu, Thomas O'Loughlin, Dennis T. Olson, J. Steven O'Malley, Cephas N. Omenyo, Muriel Orevillo-Montenegro, César Augusto Ornellas Ramos, Agbonkhianmeghe E. Orobator, Kenan B. Osborne, Carolyn Osiek, Javier Otaola Montagne, Douglas F. Ottati, Anna May Say Pa, Irina Paert, Jerry G. Pankhurst, Aristotle Papanikolaou, Samuele F. Pardini, Stefano Parenti, Peter Paris, Sung Bae Park, Cristián G. Parker, Raquel Pastor, Joseph Pathrapankal, Daniel Patte, W. Brown Patterson, Clive Pearson, Keith F. Pecklers, Nancy Cardoso Pereira, David Horace Perkins, Pheme Perkins, Edward N. Peters, Rebecca Todd Peters, Bishop Yeznik Petrossian, Raymond Pfister, Peter C. Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. Rubenstein, Rosemary Radford Ruether, Markku Ruotsila, John E. Rybolt, Risto Saarinen, John Saillant, Juan Sanchez, Wagner Lopes Sanchez, Hugo N. Santos, Gerhard Sauter, Gloria L. Schaab, Sandra M. Schneiders, Quentin J. Schultze, Fernando F. Segovia, Turid Karlsen Seim, Carsten Selch Jensen, Alan P. F. Sell, Frank C. Senn, Kent Davis Sensenig, Damían Setton, Bal Krishna Sharma, Carolyn J. Sharp, Thomas Sheehan, N. Gerald Shenk, Christian Sheppard, Charles Sherlock, Tabona Shoko, Walter B. Shurden, Marguerite Shuster, B. Mark Sietsema, Batara Sihombing, Neil Silberman, Clodomiro Siller, Samuel Silva-Gotay, Heikki Silvet, John K. Simmons, Hagith Sivan, James C. Skedros, Abraham Smith, Ashley A. Smith, Ted A. Smith, Daud Soesilo, Pia Søltoft, Choan-Seng (C. S.) Song, Kathryn Spink, Bryan Spinks, Eric O. Springsted, Nicolas Standaert, Brian Stanley, Glen H. Stassen, Karel Steenbrink, Stephen J. Stein, Andrea Sterk, Gregory E. Sterling, Columba Stewart, Jacques Stewart, Robert B. Stewart, Cynthia Stokes Brown, Ken Stone, Anne Stott, Elizabeth Stuart, Monya Stubbs, Marjorie Hewitt Suchocki, David Kwang-sun Suh, Scott W. Sunquist, Keith Suter, Douglas Sweeney, Charles H. Talbert, Shawqi N. Talia, Elsa Tamez, Joseph B. Tamney, Jonathan Y. Tan, Yak-Hwee Tan, Kathryn Tanner, Feiya Tao, Elizabeth S. Tapia, Aquiline Tarimo, Claire Taylor, Mark Lewis Taylor, Bishop Abba Samuel Wolde Tekestebirhan, Eugene TeSelle, M. Thomas Thangaraj, David R. Thomas, Andrew Thornley, Scott Thumma, Marcelo Timotheo da Costa, George E. “Tink” Tinker, Ola Tjørhom, Karen Jo Torjesen, Iain R. Torrance, Fernando Torres-Londoño, Archbishop Demetrios [Trakatellis], Marit Trelstad, Christine Trevett, Phyllis Trible, Johannes Tromp, Paul Turner, Robert G. Tuttle, Archbishop Desmond Tutu, Peter Tyler, Anders Tyrberg, Justin Ukpong, Javier Ulloa, Camillus Umoh, Kristi Upson-Saia, Martina Urban, Monica Uribe, Elochukwu Eugene Uzukwu, Richard Vaggione, Gabriel Vahanian, Paul Valliere, T. J. Van Bavel, Steven Vanderputten, Peter Van der Veer, Huub Van de Sandt, Louis Van Tongeren, Luke A. Veronis, Noel Villalba, Ramón Vinke, Tim Vivian, David Voas, Elena Volkova, Katharina von Kellenbach, Elina Vuola, Timothy Wadkins, Elaine M. Wainwright, Randi Jones Walker, Dewey D. Wallace, Jerry Walls, Michael J. Walsh, Philip Walters, Janet Walton, Jonathan L. Walton, Wang Xiaochao, Patricia A. Ward, David Harrington Watt, Herold D. Weiss, Laurence L. Welborn, Sharon D. Welch, Timothy Wengert, Traci C. West, Merold Westphal, David Wetherell, Barbara Wheeler, Carolinne White, Jean-Paul Wiest, Frans Wijsen, Terry L. Wilder, Felix Wilfred, Rebecca Wilkin, Daniel H. Williams, D. Newell Williams, Michael A. Williams, Vincent L. Wimbush, Gabriele Winkler, Anders Winroth, Lauri Emílio Wirth, James A. Wiseman, Ebba Witt-Brattström, Teofil Wojciechowski, John Wolffe, Kenman L. Wong, Wong Wai Ching, Linda Woodhead, Wendy M. Wright, Rose Wu, Keith E. Yandell, Gale A. Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
-
- Book:
- The Cambridge Dictionary of Christianity
- Published online:
- 05 August 2012
- Print publication:
- 20 September 2010, pp xi-xliv
-
- Chapter
- Export citation
A fission track thermochronological study of King George and Livingston islands, South Shetland Islands (West Antarctica)
- I. SELL, G. POUPEAU, J.M. GONZÁLEZ-CASADO, J. LÓPEZ-MARTÍNEZ
-
- Journal:
- Antarctic Science / Volume 16 / Issue 2 / June 2004
- Published online by Cambridge University Press:
- 03 June 2004, pp. 191-197
-
- Article
- Export citation
-
This paper reports the dating of apatite fission tracks in eleven rock samples from the South Shetland Archipelago, an island arc located to the north-west of the Antarctic Peninsula. Apatites from Livingston Island were dated as belonging to the Oligocene (25.8 Ma: metasediments, Miers Bluff Formation, Hurd Peninsula) through to the Miocene (18.8 Ma: tonalites, Barnard Point). Those from King George Island were slightly older, belonging to the Early Oligocene (32.5 Ma: granodiorites, Barton Peninsula). Towards the back-arc basin (Bransfield Basin), the apatite appears to be younger. This allows an opening rate of approximately 1.1 km Ma−1 (during the Miocene–Oligocene interval) to be calculated for Bransfield Basin. Optimization of the apatite data suggests cooling to 100 ± 10°C was coeval with the end of the main magmatic event in the South Shetland Arc (Oligocene), and indicates slightly different tectonic-exhumation histories for the different tectonic blocks.
Effect of Gadolinium Doping on the Air Oxidation of Uranium Dioxide
- Randall D. Scheele, Brady D. Hanson, Stephen E. Cumblidge, Evan D. Jenson, Anne E. Kozelisky, Rachel L. Sell, Paul J. MacFarlan, Lanee A. Snow
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 824 / 2004
- Published online by Cambridge University Press:
- 17 March 2011, CC8.8
- Print publication:
- 2004
-
- Article
- Export citation
-
Researchers at the Pacific Northwest National Laboratory (PNNL) investigated the effects of gadolinium oxide concentration on the air oxidization of gadolinium oxide-doped uranium dioxide using thermogravimetry and differential scanning calorimetry to determine if such doping could improve uraniumdioxide's stability as a nuclear fuel during potential accident scenarios in a nuclear reactor or during long-term disposal. We undertook this study to determine whether the resistance of the uranium dioxide to oxidation to the orthorhombic U3O8 with its attendant crystal expansion could be prevented by addition of gadolinium oxide. Our studies found that gadolinium has little effect on the thermal initiation of the first step of the reported two-step air oxidation of UO2; however, increasing gadolinium oxide content does stabilize the initial tetragonal or cubic product allowing significant oxidation before the second expansive step to U3O8 begins.
Radiation Damage in Titanate Ceramics for Plutonium Immobilization
- Denis M. Strachan, Randall D. Scheele, Anne E. Kozelisky, Richard L. Sell, H. Todd Schaef, Matthew J. O'Hara, Christopher F. Brown, and William C. Buchmiller
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 713 / 2002
- Published online by Cambridge University Press:
- 21 March 2011, JJ3.5
- Print publication:
- 2002
-
- Article
- Export citation
-
Radiation damage experiments are being performed with pyrochlore and zirconolite in support of the disposition of surplus weapons-ready Pu. Pyrochlore becomes amorphous in approximately 1 year from the alpha recoil damage of ∼ 1018 alphas/g from the decay of 238Pu. The dissolution rate of 238Pu-bearing ceramics increases with increasing radiation damage as measured in a 3 d MCC-1 test at 90°C. Over the same period, zirconolite retains substantial crystallinity albeit with broadened diffraction peaks. The dissolution rate also increases with increasing radiation damage.
Experimental Study on the Role of Hydrogen in the Breakdown of Low-Temperature Si Epitaxy
- J. Platen-Schwarzkopf, W. Bohne, W. Fuhs, K. Lips, J. Röhrich, B. Selle, I. Sieber
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 686 / 2001
- Published online by Cambridge University Press:
- 15 March 2011, A3.1
- Print publication:
- 2001
-
- Article
- Export citation
-
Homoepitaxial Si layers were grown on Si(100) at temperatures of 325 - 500 °C by Electron-Cyclotron Resonance Plasma-Enhanced Chemical Vapor Deposition (ECR PECVD) from a gas mixture of SiH4,H2 and Ar. Ar was added in order to realize high growth rates where the breakdown of epitaxy was well observed. Si disorder depth profiles derived from RBS channeling spectra were compared with hydrogen depth distributions measured by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA) and Secondary Ion Mass Spectroscopy (SIMS). The results suggest that the transition from epitaxial to amorphous growth proceeds through two stages: (1) a highly defective but still ordered growth with the defect density increasing as the growth proceeds and (2) the formation of conically shaped precipitates of amorphous Si. Both regions act as an increasingly effective sink for excessive hydrogen which diffuses from the growth surface into the bulk of the sample. In perfectly grown epitaxial films, where the overall concentration of excessive hydrogen was low, the hydrogen diffusion tail was found to extend far beyond the interface into the Si substrate.