bluuebunny/crossref_metadata_2025 huggingface dataset:
Cystatin M loss is associated with the losses of estrogen receptor, progesterone receptor, and HER4 in invasive breast cancer
Authors: Ko Eunkyung , Park Seong-Eun , Cho Eun Yoon , Kim Yujin , Hwang Jung-Ah , Lee Yeon-Su , Nam Seok Jin , Bang Saik , Park Joobae , Kim Duk-Hwan
Published: November 2010

Introduction

This study was aimed at understanding the clinicopathological significance of cystatin M loss, and investigating possible factors responsible for cystatin M loss in breast cancer.

Methods

The expression of estrogen receptor (ER), progesterone receptor (PR), HER2, HER4, and cystatin M was retrospectively analyzed using immunohistochemistry in 117 patients with ductal carcinoma in situ (DCIS) and in 175 patients with invasive breast cancer (IBC). The methylation status of CST6 gene encoding cystatin M was evaluated using methylation-specific polymerase chain reaction (PCR) in formalin-fixed paraffin-embedded tissues from 292 participants and using pyrosequencing in fresh-frozen tumor and matched normal tissues from 51 IBC patients.

Results

Cystatin M loss was found in 9 (8%) of 117 patients with DCIS and in 99 (57%) of 175 with invasive breast cancer (IBC) (P < 0.0001). Cystatin M loss was found in 58 (57%) of 101 HER2-negative IBCs and in 41 (55%) of 74 HER2-positive IBCs, and this difference was not statistically significant (P = 0.97). However, cystatin M loss was significantly associated with the loss of ER (P = 0.01), PR (P = 0.002), and HER4 (P = 0.003) in IBCs. Cystatin M loss occurred in 34 (76%) of the 45 HER4-negative IBCs and in 65 (50%) of the 130 HER4-positive IBCs. Multivariate analysis showed that cystatin M loss occurred at a 3.57 times (95% CI = 1.28 to 9.98; P = 0.01) higher prevalence in the triple-negative IBCs of ER, PR, and HER4 than in other subtypes, after adjusting for age. The quantity of CST6 methylation was associated with ER loss (P = 0.0002) in IBCs but not with the loss of PR (P = 0.64) or HER4 (P = 0.87).

Conclusions

The present study suggests that cystatin M loss may be associated with the losses of ER, PR, and HER4 in IBC.
Validation of a new transpulmonary thermodilution system to assess global end-diastolic volume and extravascular lung water
Authors: Bendjelid Karim , Giraud Raphael , Siegenthaler Nils , Michard Frederic
Published: November 2010

Introduction

A new system has been developed to assess global end-diastolic volume (GEDV), a volumetric marker of cardiac preload, and extravascular lung water (EVLW) from a transpulmonary thermodilution curve. Our goal was to compare this new system with the system currently in clinical use.

Methods

Eleven anesthetized and mechanically ventilated pigs were instrumented with a central venous catheter and a right (PulsioCath; Pulsion, Munich, Germany) and a left (VolumeView™; Edwards Lifesciences, Irvine, CA, USA) thermistor-tipped femoral arterial catheter. The right femoral catheter was used to measure GEDV and EVLW using the PiCCO2™ (Pulsion) method (GEDV1 and EVLW1, respectively). The left femoral catheter was used to measure the same parameters using the new VolumeView™ (Edwards Lifesciences) method (GEDV2 and EVLW2, respectively). Measurements were made during inotropic stimulation (dobutamine), during hypovolemia (bleeding), during hypervolemia (fluid overload), and after inducing acute lung injury (intravenous oleic acid).

Results

One hundred and thirty-seven paired measurements were analyzed. GEDV1 and GEDV2 ranged from 701 to 1,629 ml and from 774 to 1,645 ml, respectively. GEDV1 and GEDV2 were closely correlated (r2 = 0.79), with mean bias of -11 ± 80 ml and percentage error of 14%. EVLW1 and EVLW2 ranged from 507 to 2,379 ml and from 495 to 2,222 ml, respectively. EVLW1 and EVLW2 were closely correlated (r2 = 0.97), with mean bias of -5 ± 72 ml and percentage error of 15%.

Conclusions

In animals, and over a very wide range of values, a good agreement was found between the new VolumeView™ system and the PiCCO™ system to assess GEDV and EVLW.
Integrative Genomic Analysis of Medulloblastoma Identifies a Molecular Subgroup That Drives Poor Clinical Outcome
Authors: Cho Yoon-Jae , Tsherniak Aviad , Tamayo Pablo , Santagata Sandro , Ligon Azra , Greulich Heidi , Berhoukim Rameen , Amani Vladimir , Goumnerova Liliana , Eberhart Charles G. , Lau Ching C. , Olson James M. , Gilbertson Richard J. , Gajjar Amar , Delattre Olivier , Kool Marcel , Ligon Keith , Meyerson Matthew , Mesirov Jill P. , Pomeroy Scott L.
Published: November 2010

Purpose

Medulloblastomas are heterogeneous tumors that collectively represent the most common malignant brain tumor in children. To understand the molecular characteristics underlying their heterogeneity and to identify whether such characteristics represent risk factors for patients with this disease, we performed an integrated genomic analysis of a large series of primary tumors.

Patients and Methods

We profiled the mRNA transcriptome of 194 medulloblastomas and performed high-density single nucleotide polymorphism array and miRNA analysis on 115 and 98 of these, respectively. Non-negative matrix factorization–based clustering of mRNA expression data was used to identify molecular subgroups of medulloblastoma; DNA copy number, miRNA profiles, and clinical outcomes were analyzed for each. We additionally validated our findings in three previously published independent medulloblastoma data sets.

Results

Identified are six molecular subgroups of medulloblastoma, each with a unique combination of numerical and structural chromosomal aberrations that globally influence mRNA and miRNA expression. We reveal the relative contribution of each subgroup to clinical outcome as a whole and show that a previously unidentified molecular subgroup, characterized genetically by c-MYC copy number gains and transcriptionally by enrichment of photoreceptor pathways and increased miR-183∼96∼182 expression, is associated with significantly lower rates of event-free and overall survivals.

Conclusion

Our results detail the complex genomic heterogeneity of medulloblastomas and identify a previously unrecognized molecular subgroup with poor clinical outcome for which more effective therapeutic strategies should be developed.
Phase III, Randomized Study of the Effects of Parenteral Iron, Oral Iron, or No Iron Supplementation on the Erythropoietic Response to Darbepoetin Alfa for Patients With Chemotherapy-Associated Anemia
Authors: Steensma David P. , Sloan Jeff A. , Dakhil Shaker R. , Dalton Robert , Kahanic Stephen P. , Prager Diane J. , Stella Philip J. , Rowland Kendrith M. , Novotny Paul J. , Loprinzi Charles L.
Published: November 2010

Purpose

Functional iron deficiency may impair response to erythropoiesis-stimulating agents (ESAs) in iron-replete patients with chemotherapy-associated anemia (CAA). This study evaluated whether coadministration of parenteral iron improves ESA efficacy in patients with CAA.

Patients and Methods

This prospective, multicenter, randomized trial enrolled 502 patients with hemoglobin (Hb) less than 11 g/dL who were undergoing chemotherapy for nonmyeloid malignancies. All patients received darbepoetin alfa once every 3 weeks and were randomly assigned to receive either ferric gluconate 187.5 mg intravenously (IV) every 3 weeks, oral daily ferrous sulfate 325 mg, or oral placebo for 16 weeks.

Results

There was no difference in the erythropoietic response rate (ie, proportion of patients achieving Hb ≥12 g/dL or Hb increase ≥ 2 g/dL from baseline): 69.5% (95% CI, 61.9% to 76.5%) of IV iron-treated patients achieved an erythropoietic response compared with 66.9% (95% CI, 59.1% to 74.0%) who received oral iron and 65.0% (95% CI, 57.2% to 72.3%) who received oral placebo (P = .75). There were also no differences in the proportion of patients requiring red cell transfusions, changes in quality of life, or the dose of darbepoetin administered. Adverse events (AEs) tended to be more common in the IV iron arm: grade 3 or higher AEs occurred in 54% (95% CI, 46% to 61%) of patients receiving IV iron compared with 44% (95% CI, 36% to 52%) who received oral iron and 46% (95% CI, 38% to 54%) who received oral placebo (P = .16).

Conclusion

In patients with CAA, addition of IV ferric gluconate to darbepoetin failed to provide additional benefit compared with oral iron or oral placebo.
A conserved germline multipotency program
Authors: Juliano Celina E. , Swartz S. Zachary , Wessel Gary M.
Published: November 2010

The germline of multicellular animals is segregated from somatic tissues, which is an essential developmental process for the next generation. Although certain ecdysozoans and chordates segregate their germline during embryogenesis, animals from other taxa segregate their germline after embryogenesis from multipotent progenitor cells. An overlapping set of genes, including vasa, nanos and piwi, operate in both multipotent precursors and in the germline. As we propose here, this conservation implies the existence of an underlying germline multipotency program in these cell types that has a previously underappreciated and conserved function in maintaining multipotency.
Foxj1 regulates floor plate cilia architecture and modifies the response of cells to sonic hedgehog signalling
Authors: Cruz Catarina , Ribes Vanessa , Kutejova Eva , Cayuso Jordi , Lawson Victoria , Norris Dominic , Stevens Jonathan , Davey Megan , Blight Ken , Bangs Fiona , Mynett Anita , Hirst Elizabeth , Chung Rachel , Balaskas Nikolaos , Brody Steven L. , Marti Elisa , Briscoe James
Published: November 2010

Sonic hedgehog signalling is essential for the embryonic development of many tissues including the central nervous system, where it controls the pattern of cellular differentiation. A genome-wide screen of neural progenitor cells to evaluate the Shh signalling-regulated transcriptome identified the forkhead transcription factor Foxj1. In both chick and mouse Foxj1 is expressed in the ventral midline of the neural tube in cells that make up the floor plate. Consistent with the role of Foxj1 in the formation of long motile cilia, floor plate cells produce cilia that are longer than the primary cilia found elsewhere in the neural tube, and forced expression of Foxj1 in neuroepithelial cells is sufficient to increase cilia length. In addition, the expression of Foxj1 in the neural tube and in an Shh-responsive cell line attenuates intracellular signalling by decreasing the activity of Gli proteins, the transcriptional mediators of Shh signalling. We show that this function of Foxj1 depends on cilia. Nevertheless, floor plate identity and ciliogenesis are unaffected in mouse embryos lacking Foxj1 and we provide evidence that additional transcription factors expressed in the floor plate share overlapping functions with Foxj1. Together, these findings identify a novel mechanism that modifies the cellular response to Shh signalling and reveal morphological and functional features of the amniote floor plate that distinguish these cells from the rest of the neuroepithelium.
Collagen XIXa1 is crucial for motor axon navigation at intermediate targets
Authors: Hilario Jona D. , Wang Chunping , Beattie Christine E.
Published: November 2010

During development, motor axons navigate from the spinal cord to their muscle targets in the periphery using stereotyped pathways. These pathways are broken down into shorter segments by intermediate targets where axon growth cones are believed to coordinate guidance cues. In zebrafish stumpy mutants, embryonic development proceeds normally; however, as trunk motor axons stall at their intermediate targets, suggesting that Stumpy is needed specifically for motor axon growth cones to proceed past intermediate targets. Fine mapping and positional cloning revealed that stumpy was the zebrafish homolog of the atypical FACIT collagen collagenXIXa1 (colXIX). colXIX expression was observed in a temporal and spatial pattern, consistent with a role in motor axon guidance at intermediate targets. Knocking down zebrafish ColXIX phenocopied the stumpy phenotype and this morpholino phenotype could be rescued by adding back either mouse or zebrafish colXIX RNA. The stumpy phenotype was also partially rescued in mutants by first knocking down zebrafish ColXIX and adding back colXIX RNA, suggesting that the mutation is acting as a dominant negative. Together, these results demonstrate a novel function for a FACIT collagen in guiding vertebrate motor axons through intermediate targets.
Reaction dynamics in the formidable gap
Authors: Boulatov Roman
Published: November 2010

One of the least understood and least exploited aspects of nanoscience is dynamic coupling between directional translation at mesoscales (lengths above ~50 nm) and changes in local chemical bonding (lengths below ~1 nm). A major cause is the traditional dominance of two distinct and seemingly incompatible models for describing dynamics at the two scales: continuum mechanics based on the balance of forces, i.e., mechanical equilibrium (lengths above ~50 nm) and activated escape from an energy well, i.e., chemical equilibrium (below ~1 nm). These models yield meaningful results within their respective dimensional limits but leave processes in between in the gray area of conceptual ambiguity and technical intractability. Such processes underlie phenomena as diverse as catastrophic failure of strained materials, operation of motor polymers, behavior of polymer flows, and mechanosensing. Chemomechanics integrates the two conventional dynamic models into a single internally consistent, scale-independent framework that is essential for a quantitative understanding and the efficient exploitation of dynamic coupling across the “formidable gap” at ~1–50 nm. Chemomechanics holds promise (1) to facilitate significantly the design of new stress-responsive and actuating polymers, including those optimized specifically for the propulsion of autonomous nanomechanical devices and for use in micro- and nanoscale stress sensors; and (2) to yield general predictive molecular relationships between chemical composition, structure, and mechanical properties of polymers both at the single-chain and bulk levels. Theoretical and experimental studies of dynamic coupling across the formidable gap have traditionally been carried out within soft-matter physics. As far as I am aware, my group was the first to approach the problem from a chemist’s perspective. Below, I summarize the state-of-the-art of chemical understanding of processes in the formidable gap from both theoretical and experimental perspectives.
Interaction between COX-2 G-765C and smoking in relation to coronary artery disease in a Chinese Uighur population
Authors: Xie Xiang , Ma Yi-Tong , Yang Yi-Ning , Fu Zhen-Yan , Li Xiao-Mei , Huang Ding , Ma Xiang , Chen Bang-dang , Liu Fen
Published: November 2010

Background: Coronary artery disease (CAD) is a complex multifactorial and polygenic disorder where multiple environmental and genetic factors are involved simultaneously. The purpose of this study was to explore the relationship between the interaction of cyclooxygenase-2 (COX-2) gene polymorphism and smoking and CAD in a Uighur population.

Methods: Using a case-control study of Chinese Uighur CAD patients (n=430) and healthy controls (n=470), we investigated the roles of G-765C polymorphism in the COX-2 gene (PTGS2) by the use of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

Results: The PTGS2 GG genotype was significantly more prevalent in CAD patients (84.6% vs. 78.3%; p=0.014). Multiple logistic regression analysis showed two independent risk factors: smoking (OR 1.89, 95% CI 1.01–5.24; p=0.008) and hypertension (OR 2.73, 95% CI 1.59–7.21; p=0.001). Moreover, there was a synergistic effect between smoking and the PTGS2 polymorphism and the occurrence of CAD (interaction p=0.009). The odds ratio (OR) estimated by the combined analysis of the PTGS2 GG genotype and smoking history (OR 4.09, 95% CI 2.7–9.3) was markedly higher than that estimated separately from the PTGS2 GG genotype (OR 1.28, 95% CI 0.8–1.9) or smoking (OR 2.51, 95% CI 1.5–5.7) alone. Plasma 6-keto-PGF1α, a stable metabolite of PGI2, was lower in individuals with the PTGS2 GG genotype (p<0.05). Smoking could further lower plasma 6-keto-PGF1α concentrations in GG genotype carriers than non-smokers, especially in patients with CAD.

Conclusions: The PTGS2 polymorphism and smoking were synergistically and significantly associated in Chinese Uighur patients with CAD.
Global trends in critical values practices and their harmonization
Authors: Kost Gerald J. , Hale Kristin N.
Published: November 2010

Background:The objectives of this article were 1) to identify current trends in critical values practices in North America, Europe, and other regions; 2) to describe progress toward harmonization of critical limits; and 3) to synthesize strategies that will encourage global consensus. Critical limits are described in national surveys. Critical value practices are guided by federal statutes, The Joint Commission regulations, and accreditation requirements in the US; by provincial healthcare agencies in Canada; by thought leaders and ISO EN 15189:2007 in Europe; and in SE Asia, mostly by ad hoc policies lacking statutory grip.

Methods:Review of databases, literature, websites, federal statutes, litigation, official policies, current affairs, and accreditation agency requirements.

Results and conclusions:Practical strategies will accelerate harmonization of critical values practices, as follows: a) continue national and international survey comparisons; b) clarify age, ethnic, and subject dependencies; c) standardize qualitative and quantitative decision levels for urgent clinician notification; d) monitor compliance and timeliness for safety; and e) alert high frequencies of critical values related to adverse events. New expectations and communication technologies present opportunities for enhanced performance using wireless closed-loop reporting with recipient acknowledgment to reduce phone calls and improve efficiency. Hospitals worldwide can benefit from developing consensus for critical values practices.
Biological variation of free β chorionic gonadotropin and pregnancy-associated plasma protein A in first trimester pregnancies
Authors: Sennels Henriette P. , Jørgensen Finn Stener , Sørensen Steen
Published: November 2010

Background: Trisomy 21 risk estimation in first trimester pregnancies can be performed by a combined test based on ultrasound measurement of fetal nuchal translucency thickness and maternal plasma concentrations of free β human chorionic gonadotropin (hCGβ) and pregnancy-associated plasma protein A (PAPP-A). However, little knowledge exists regarding the biological variation of hCGβ and PAPP-A when the time interval between sampling increases.

Methods: We estimated these variations from double mea-surements of hCGβ and PAPP-A in first trimester pregnancies in 167 women. Data were divided into three groups based on the number of days between sampling. The correlation coefficients and biological variation were estimated for each group.

Results: The correlation coefficient between the first and second samples was 0.841 for hCGβ, and 0.706 for PAPP-A. The ranges for biological variation were 11.9%–48.5% for hCGβ and 31.6%–63.3% for PAPP-A, increasing with time between sampling. The average overall biological variation for hCGβ was 29%, and 49.7% for PAPP-A.

Conclusions: We found high biological variation for plasma concentrations of hCGβ and PAPP-A, increasing with longer time intervals between sampling. From our data that showed high correlation of hCGβ and PAPP-A in the first and second sample, we found no reason to recommend retesting. However, new studies should clarify whether PAPP-A should be collected early, and hCGβ late, in the first trimester of pregnancy.
Effect of reduction on the stability of Pu(VI) hydrolysis species
Authors: Cho Hye-Ryun , Jung E. C. , Park K. K. , Song K. , Yun Jong-Il
Published: November 2010

The chemical speciation of aqueous plutonium species has been performed by spectrophotometry. The main focus was concentrated on the effect of Pu(V) produced by the reduction of Pu(VI) on the stability of the Pu(VI) hydrolysis species. In order to detect the trace amounts of PuO2+ions, a liquid waveguide capillary cell with an optical path length of 100 cm was connected to a spectrophotometer. As a consequence of the improved detection sensitivity, an absorption band at 569 nm being indicative of Pu(V) was observed within one day after the sample preparation from the pure Pu(VI) solution. The first hydrolysis species was (PuO2)2(OH)22+, at plutonium concentrations of 0.1–0.12 mM and at weak acidic conditions (pH 5–6). The formation constant of (PuO2)2(OH)22+was determined to be log*β′22=−7.34±0.22 at 0.01 M NaClO4. This dinuclear hydroxide species was unstable and disappeared within one month after the sample preparation at the present experimental condition. In the neutral pH range, the second hydrolysis species was formed and remained for over one year. The samples showed different behavior for the reduction of Pu(VI). The time dependent distribution of plutonium species and their characteristic features in the absorption spectra are reported.
Retention and redox behaviour of uranium(VI) by siderite (FeCO3)
Authors: Ithurbide Aurélie , Peulon Sophie , Miserque Frédéric , Beaucaire Catherine , Chaussé Annie
Published: November 2010

In the context of long-term nuclear waste management, understanding the migration of a major component of spent fuel, uranium namely, in the environment is of major importance. This study presents the kinetics of uranium(VI) retention and reduction in carbonate solutions by siderite, an iron carbonate present both in the near- and far-field. At pH 9, uranium(VI) is retained at the surface, reduced and then precipitated into UO2.67. At pH 7, uranium(VI) seems, first, to be incorporated into iron precipitates at the solid/liquid interface and, subsequently, reduced by the Fe(II) contained in the thin layer.
Complexation of Tc(IV) with acetate at varying ionic strengths
Authors: Boggs Mark A. , Dong Wenming , Gu Baohua , Wall Nathalie A.
Published: November 2010

In order to accurately model and predict the fate and transport of metals and radionuclides at multiple radio-contaminated sites, there is a need for an understanding on how metals such as technetium interact with their environment. Many contaminated sites are known to contain large amounts of organic ligands that can affect the solubility and mobility of metals. This study focuses on the effect of acetate on the complexation and dissolution of Tc(IV). Studies were performed at pcH 4.5 (±0.3), at which TcOOH+ is the predominant species. The stability constants for the TcOOH-acetate complex were determined at ionic strengths varying from 0.5 to 3.0 M (NaCl), using a solvent extraction method. The stability constants showed the expected increasing trend over the range of ionic strengths, from 2.46±0.03 (I=0.5) to 3.09±0.08 (I=3.0). A stability constant of 2.8±0.16 at zero ionic strength was determined by specific ion interaction theory. Geochemical modeling data suggest that the dissolution of TcO2·1.6H2O is not greatly affected by the presence of acetate, at concentrations equal or less than 20 mM.
Uranyl photochemistry: decarboxylation of gluconic acid
Authors: Zhang Zhicheng , Helms Gregory , Nash Kenneth L. , Clark Sue B.
Published: November 2010

In weakly acidic aqueous solutions, uranyl is able to slowly photolyze gluconic acid under ambient laboratory light (fluorescence lamps). The photolysis follows “complex formation”, resulting in the decarboxylation of gluconic acid (CH2OH(CHOH)4COOH) to form D-arabinose ((CHOH)4OCH2). A possible pathway is proposed to be the sensitized photo-oxidation, which can be described as U(VI)·CH2OH(CHOH)4COOH → U(V) + CH2OH(CHOH)3ĊHOH + CO2 + H+ and U(V) + CH2OH(CHOH)3ĊHOH + H+ → U(VI) + (CHOH)4OCH2 + H2. Also, characterization of the precipitate observed in the photolytic samples demonstrates the presence of tetravalent U, which we believe is generated by concurrent disproportionation of intermediate pentavalent U.
Quantum chemical study of inner-sphere complexes of trivalent lanthanide and actinide ions on the corundum (0001) surface
Authors: Polly Robert , Schimmelpfennig Bernd , Rabung Thomas , Flörsheimer Mathias , Klenze Reinhardt , Geckeis H.
Published: November 2010

Sorption of trivalent metal ions onto mineral surfaces is of special relevance in the safety assessment of nuclear waste disposal. In the present quantum chemical study we mainly focused on understanding the interaction of trivalent metal ions (La3+, Eu3+ and Cm3+) with the corundum (0001) the surface. We studied how the structure of the inner-sphere complex at the corundum (0001) surface depends on the deprotonation of the surface and give a prediction for the most likely structure of the inner-sphere complex (bi-, tri- or tetradentate). We approached this question using a cluster model for the surface. By deprotonating the cluster we mimicked a chemical environment at pH values above the point of zero charge. In a first step, we tested the accuracy of Density Functional Theory calculations with the BP86 functional and various basis sets by comparing them with Møller-Plesset perturbation theory of second order on a small chemically similar test system. This is followed by a series of calculations on a large and realistic cluster which is an extended model for the formation of the inner-sphere complex at the corundum (0001) surface. Our calculations predict the highest stability for a species with six water molecules remaining in the first coordination sphere of the metal ions and forming an inner-sphere surface complex attached to three surface oxygen atoms. The formation of the inner-sphere complexes is even more favoured when the coordination takes place via one or two deprotonated surface oxygen atoms.
Interaction of PuO2thin films with water
Authors: Seibert Alice , Gouder T. , Huber F.
Published: November 2010

The surface adsorption and reaction of water with PuO2thin films was investigated by X-ray and ultra-violet photoelectron spectroscopies (XPS and UPS, respectively). Initial motivation of the work was to further investigate the potential role of water in promoting the surface oxidation of PuO2to Pu(IV)/Pu(V) mixed oxides formerly discussed in literature which may seriously impede the stability of spent nuclear fuel. Water may act as oxidant, as catalyst for the oxidation by O2, or as reactant leading to formation of hydrous oxide being oxidized by O2instead of PuO2(cr). In order to obtain high water coverage under the experimentally required ultra-high vacuum conditions, water was adsorbed at low temperature (77 K) as thick ice film. Results were compared to thin water layers adsorbed at room temperature.

When adsorbed at 298 K, water dissociates forming a thin hydroxyl (OH−) layer with small amounts of molecularly adsorbed water but no further reaction (in the sense of oxidation or reduction) is detected. At 77 K, water condenses as ice film. Here, a mainly non-dissociative adsorption of water is observed for layers ∼1 ML while for higher dosages, only molecular water/ice is observed and no significant contribution of OH (in the water layers) is detected. When exposing the sample to UV light while warming it up, the ice layer thaws and desorbs leaving behind a Pu2O3surface. This surprising reduction of PuO2stands in sharp contrast to the radiolytically driven oxidation of spent fuel in presence of water. It is discussed in terms of a photochemically driven interface reaction.
Chlorine speciation in nuclear graphite: consequences on temperature release and on leaching
Authors: Vaudey C.-E. , Toulhoat N. , Moncoffre N. , Bérerd N.
Published: November 2010

This paper aims to get information on pristine chlorine speciation and its evolution with temperature in nuclear graphite used as a moderator in the first generation UNGG French reactors. For this purpose, temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) have been carried out on samples annealed in the temperature range 200–1000 °C. Two chemical forms of different thermal stabilities have been identified. Around 70% of chlorine is assigned to stable organic chlorine bound to aromatic carbon whereas around 30% is assigned to inorganic thermally labile oxychlorinated groups. The consequences for direct disposal are discussed.
Chemical status of U(VI) in cemented waste forms under saline conditions
Authors: Kienzler Bernhard , Metz Volker , Brendebach Boris , Finck N. , Plaschke Markus , Rabung Thomas , Rothe J. , Schild D.
Published: November 2010

Retention of U(VI) in cemented waste forms reacting with NaCl and MgCl2brines is investigated in long-term leaching experiments on full scale monoliths. Solution compositions were monitored over a period of 17 to 18 years. After termination of the leaching experiments, chemical and mineralogical compositions of solid reaction products were studied intensively. XRD, TRLFS and XANES/EXAFS analyses indicate uranophane (Ca(UO2)2(SiO3OH)2·5H2O) to be the dominant uranium bearing phase in the corroded cement. Other possible uranium phases such as soddyite, meta-schoepite, and di-uranate phases could not be identified by combining the results of the various experimental techniques.
Modelling of a large-scalein-situmigration experiment with14C-labelled natural organic matter in Boom Clay
Authors: Martens E. , Maes Norbert , Weetjens E. , Van Gompel M. , Van Ravestyn L.
Published: November 2010

For the assessment of the long-term safety of a geological disposal of high- and intermediate-level radioactive waste and/or spent fuel in the Boom Clay, a better understanding of the migration behaviour of Natural Organic Matter (NOM) is needed because it can act as a carrier molecule for radionuclides. Therefore, anin-situmigration experiment with14C-labelled NOM was performed to study the NOM migration behaviour on a large scale (m), on the long-term (>10 a) and in directions parallel and perpendicular to the bedding plane (transport anisotropy). The numerical modelling tool HYDRUS2D/3D was used to interpret the results. The model was built stepwise, testing the influence of advection, (non-)linear equilibrium sorption, colloid attachment/detachment and anisotropy. The up scaling of previously determined parameters from small scale lab tests was also tested. A classic diffusion-advection-retardation description, using parameter values in the range of those obtained in the lab tests, provided already reasonable results. Inclusion of a colloid filtration term in the model significantly improved the simulation. Finally, the model was successfully tested against a second dataset and the anisotropy of the Boom clay was brought into account.
Sorption and diffusion of Eu in sedimentary rock in the presence of humic substance
Authors: Seida Y. , Terashima M. , Tachi Y. , Iijima Kazuki , Nakazawa T. , Yamada M. , Yui Mikazu
Published: November 2010

Sorption and diffusion behaviors of Eu in sedimentary rock in the presence of humic substance were investigated. The sedimentary rock collected from 500 m depth of HDB-6 bore hole at horonobe URL site of Japan and Aldrich humic acid (HA) were used in the present study. Sorption behaviors of Eu and the HA on the sedimentary rocks with and without the rock organic matter (ROM) were elucidated as a function of HA concentration. The HA reduced the sorption of Eu on the rock with the increase of HA. Eu and HA sorption on the rock with the ROM was larger than on the rock after removing the ROM, indicating that the ROM plays an important role on the sorption of Eu and HA. The diffusion of Eu in the presence of HA was examined as a function of HA concentration and molecular weight of the HA (∼150 kDa or below 10 kDa) by means of a reservoir depletion test method with the intact rock core of the sedimentary rock. Depletion of Eu concentration in the reservoir was reduced with the increase of HA concentration. On the other hand, slight depletion of HA concentration in the reservoir was observed, indicating that the larger HA molecule diffused less into the rock. From the depletion curve and in-diffusion profile of Eu in the rock, the effective diffusion coefficient, D
e, and distribution coefficient, K
d, in the intact system were estimated based on the profile fitting of the diffusion data with the conventional simple diffusion-sorption model. It was elucidated that the HA reduced the K
d and D
e of Eu in the intact system with the increase of HA. The contribution of the HA with smaller molecular weight to both the Eu sorption and diffusion was examined.
Diffusion and sorption of neptunium(V) in compacted montmorillonite: effects of carbonate and salinity
Authors: Tachi Y. , Nakazawa T. , Ochs Michael , Yotsuji K. , Suyama T. , Seida Y. , Yamada N. , Yui Mikazu
Published: November 2010

Diffusion and sorption of radionuclides in compacted bentonite/montmorillonite are key processes in the safe geological disposal of radioactive waste. In this study, the effects of carbonate and salinity on neptunium(V) diffusion and sorption in compacted sodium montmorillonite were investigated by experimental and modeling approaches. Effective diffusion coefficients (De) and distribution coefficients (Kd) of237Np(V) in sodium montmorillonite compacted to a dry density of 800 kg m−3were measured under four chemical conditions with different salinities (0.05/0.5 M NaCl) and carbonate concentrations (0/0.01 M NaHCO3).Devalues for carbonate-free conditions were of the order of 10−10–10−11 m2s−1and decreased as salinity increased, and those for carbonate conditions were of the order of 10−11–10−12 m2s−1and showed the opposite dependence. Diffusion-derivedKdvalues for carbonate-free conditions were higher by one order of magnitude than those for carbonate conditions. Diffusion and sorption behaviors were interpreted based on mechanistic models by coupling thermodynamic aqueous speciation, thermodynamic sorption model (TSM) based on ion exchange, and surface complexation reactions, and a diffusion model based on electrical double layer (EDL) theory in homogeneous narrow pores. The model predicted the experimentally observed tendency ofDeandKdqualitatively, as a result of the following mechanisms; 1) the dominant aqueous species are NpO2+and NpO2CO3−for carbonate-free and carbonate conditions, respectively, 2) the effects of cation excess and anion exclusion result in opposite tendencies ofDefor salinity, 3) higher carbonate in solution inhibits sorption due to the formation of carbonate complexes.
Mechanisms of plutonium sorption to mineral oxide surfaces: new insights with implications for colloid-enhanced migration
Authors: Schwantes J. M. , Santschi Peter H.
Published: November 2010

New equilibrium and kinetic models have been developed to describe rate-limited sorption and desorption of Pu onto and off of mineral oxide surfaces using a generic approach to estimate sorption constants that require minimal laboratory calibrations. Equilibrium reactions describing a total of six surface species were derived from a combination of empirical relationships previously described in the literature and generated as part of this work. These sorption reactions and corresponding equilibrium constants onto goethite (and silica) are:

≡SOH + Pu3+ ↔ ≡SOPu2+ + H+, logߙK = −2.1(−10)  (1)

≡SOH + Pu4+ ↔ ≡SOPu3+ + H+, logߙK = 15.3(7.2)  (2)

≡SOH + PuO2
+ ↔ ≡SOPuO2 + H+, logߙK = −8.5(−16.5)  (3)

≡SOH + PuO2
2+ ↔ ≡SOPuO2
+ + H+, logߙK = 1.2(−6.5)  (4)

≡SOH + Pu4+ + 3H2O ↔ ≡SOPu(OH)3 + 4H+, logߙK = 12.5(4.6)  (5)

≡SOH + Pu4+ + 4H2O ↔ ≡SOPu(OH)4
− + 5H+, logߙK = 5.0(−2.3)  (6)

The kinetic model decouples reduced (III, IV) and oxidized (V, VI) forms of Pu via a single rate-limiting, but reversible, surface mediated reaction:...
Understanding uranium behaviour at the Askola uranium mineralization
Authors: Jokelainen Lalli , Markovaara-Koivisto Mira , Read David , Lindberg Antero , Siitari-Kauppi Marja , Hellmuth Karl-Heinz
Published: November 2010

Understanding the behaviour of uranium is essential when assessing the safety of a spent nuclear fuel repository. The geochemical behaviour of uranium, including its reactive transport chemistry, is also a matter of concern when assessing the environmental impact of uranium mining. Subsurface uranium mobility is believed to be primarily controlled by dissolution and (co)-precipitation of uranium mineral solids and adsorption to mineral surfaces.

This paper describes a modelling exercise based on characterisation of samples taken from drilled cores at the uranium mineralization at Askola, Southern Finland. In the modelling exercise, current conditions are assumed to be oxidizing and saturated with groundwater. PHREEQC was used for modelling in conjunction with the Lawrence Livermore National Laboratory database, chosen for its extensive coverage of uranium species and mineral phases.

It is postulated that weathering processes near the surface have led to uranium dissolution from the primary ore, leaching out from the matrix and migrating along water-conducting fractures with subsequent re-diffusion into the rock matrix. Electron microscopy studies show that precipitated uranium occupies intra-granular fractures in feldspars and quartz. In addition, secondary uranium was found to be distributed within goethite nodules as well as around the margins of iron-containing minerals in the form of silicate and phosphate precipitates. Equilibrium modelling calculations predict that uranium would be precipitated as uranyl silicates, most likely soddyite and uranophane, in the prevailing chemical conditions beneath Lakeakallio hill.
Adolescents' Needs for Health Care Privacy
Authors: Britto Maria T. , Tivorsak Tanya L. , Slap Gail B.
Published: November 2010

OBJECTIVE:

To understand adolescents' preferences for multidimensional aspects of privacy, including psychological, social, and physical, and confidentiality (informational privacy) in the health care setting.

PATIENTS AND METHODS:

Fifty-four adolescents with and without chronic illness participated in 12 focus groups composed of participants of the same age (11–14 or 15–19 years), gender, and health status. Health care preferences, including privacy and confidentiality, were discussed, and themes were determined. On the basis of a literature review, Burgoon's framework best represented participant feedback. The data were categorized as representations of informational, psychological, social, or physical privacy.

RESULTS:

Maintaining informational privacy (ie, keeping information confidential) was most salient to the adolescents. Younger adolescents were concerned with information being disclosed to others (ie, health care providers), whereas older adolescents worried more about information being disclosed to parents. Other privacy aspects (psychological, social, and physical) also were important. To protect psychological privacy, adolescents were cautious about revealing sensitive information for fear of being judged by providers. To protect social privacy, they were reluctant to talk with unfamiliar or multiple providers, and they did not want to discuss issues they perceived as unrelated to their health care. Adolescents who commented about physical privacy said that they thought about their physical safety during physical examinations, as well as their visibility to others, and said that they were more comfortable when examinations were performed by female rather than male providers.

CONCLUSIONS:

Adolescents value all aspects of privacy. Providers should address not only informational but also psychological, social, and physical privacy to improve the care of adolescent patients.
Febrile Infants With Urinary Tract Infections at Very Low Risk for Adverse Events and Bacteremia
Authors: Schnadower David , Kuppermann Nathan , Macias Charles G. , Freedman Stephen B. , Baskin Marc N. , Ishimine Paul , Scribner Camille , Okada Pamela , Beach Heather , Bulloch Blake , Agrawal Dewesh , Saunders Mary , Sutherland Donna M. , Blackstone Mercedes M. , Sarnaik Amit , McManemy Julie , Brent Alison , Bennett Jonathan , Plymale Jennifer M. , Solari Patrick , Mann Deborah J. , Dayan Peter S. ,   for the American Academy of Pediatrics Pediatric Emergency Medicine Collaborative Research Committee
Published: November 2010

BACKGROUND:

There is limited evidence from which to derive guidelines for the management of febrile infants aged 29 to 60 days with urinary tract infections (UTIs). Most such infants are hospitalized for ≥48 hours. Our objective was to derive clinical prediction models to identify febrile infants with UTIs at very low risk of adverse events and bacteremia in a large sample of patients.

METHODS:

This study was a 20-center retrospective review of infants aged 29 to 60 days with temperatures of ≥38°C and culture-proven UTIs. We defined UTI by growth of ≥50 000 colony-forming units (CFU)/mL of a single pathogen or ≥10 000 CFU/mL in association with positive urinalyses. We defined adverse events as death, shock, bacterial meningitis, ICU admission need for ventilator support, or other substantial complications. We performed binary recursive partitioning analyses to derive prediction models.

RESULTS:

We analyzed 1895 patients. Adverse events occurred in 51 of 1842 (2.8% [95% confidence interval (CI): 2.1%–3.6%)] and bacteremia in 123 of 1877 (6.5% [95% CI: 5.5%–7.7%]). Patients were at very low risk for adverse events if not clinically ill on emergency department (ED) examination and did not have a high-risk past medical history (prediction model sensitivity: 98.0% [95% CI: 88.2%–99.9%]). Patients were at lower risk for bacteremia if they were not clinically ill on ED examination, did not have a high-risk past medical history, had a peripheral band count of <1250 cells per μL, and had a peripheral absolute neutrophil count of ≥1500 cells per μL (sensitivity 77.2% [95% CI: 68.6%–84.1%]).

CONCLUSION:

Brief hospitalization or outpatient management with close follow-up may be considered for infants with UTIs at very low risk of adverse events.
De-Centering Religion as Queer Pedagogical Practice
Authors: Young Thelathia
Published: November 2010

Inasmuch as the value of teaching rests in its liberating consciousness-raising possibilities, teaching theological ethics ought to aim toward and build upon justice-oriented practice. My efforts at justice-making in the classroom, especially around the subjects of race, gender, and sexuality, assume the necessity of diverse individual’s and communities’ real experiences of moral agency, thereby de-centering religion as the norm for doing ethics. Thus, religion, and specifically Christianity, becomes a source within the scholarly endeavor. In this paper, I delineate my own experiences and practices of teaching race, gender and sexuality in two contexts, offering explanations of the ways those practices de-center religious perspectives and privilege experience as a source.
"I Too Could Be Gay If I Wanted"
Authors: Herrero-Brasas Juan
Published: November 2010

An important factor in the social rejection and marginalization of queer people is misplaced empathy. When it comes to sexual identity, putting oneself in someone else's shoes, if bringing into those shoes a radically non-queer emotional experience, will only lead to further lack of understanding and misconceptions. The religious studies classroom provides a privileged setting for exposing that wrong kind of empathy and help the students reflect about the ways in which negative religious attitudes to queerness may be tainted with it.
Sound of the Surf
Authors: Weep Reed
Published: November 2010

Reed M. N. Weep Column
Tooth-Implant Connection: A Review
Authors: Hoffmann Oliver , Zafiropoulos Gregory-George
Published: November 2010

The aim of this review was to assess the long-term outcomes of restorations supported by implants and natural teeth with regard to complications associated with implants, teeth, and restorations, as well as the influence on these parameters of the connector type used. A net-based search in PubMed was combined with a manual search. Clinical studies, reviews, and biomechanical studies were included. Information on survival rate, complication rate, incidence of tooth intrusion, and, where applicable, type of connector used, was retrieved from the clinical studies. Force distribution and types of connectors used were retrieved from the biomechanical study. A summary of outcomes was retrieved from the reviews. A total of 25 articles were selected for inclusion in this review, including clinical studies (15), biomechanical studies (7), and reviews (3). Implant success rates ranged from 79.5%–100%. Tooth complications occurred in 5.4%–11.8% of cases. Complications in the suprastructure were observed in 5%–90% of cases. Tooth intrusion presented in a total of 0%–66% of all cases, more often in cases with nonrigid connection (0%–66%) than in cases with rigid connection (0%–44%). Biomechanical studies show a large difference in stress distribution and in dependence on the type of connector used, with most studies demonstrating that nonrigid connectors drastically reduce stress on the suprastructure while increasing forces on supporting teeth and implants. Long-term success rates for tooth-implant connections are lower than for solely implant-supported restorations with regard to prognosis for teeth, implants, and suprastructure. Use of rigid connectors leads to more favorable clinical outcomes in terms of long-term stability, occurrence of complications, and tooth intrusion.
A Comparison Between Screw- and Cement-Retained Implant Prostheses. A Literature Review
Authors: Shadid Rola , Sadaqa Nasrin
Published: November 2010

Implant-supported restorations can be secured to implants with screws (screw-retained), or they can be cemented to abutments which are attached to implants with screws (cement-retained). This literature review discusses the advantages and disadvantages of each method of retention from different aspects. These aspects include: ease of fabrication and cost, esthetics, access, occlusion, retention, incidence of loss of retention, retrievability, clinical prosthesis fit, restriction of implant position, effect on peri-implant tissue health, provisionalization, immediate loading, impression procedures, porcelain fracture, and clinical performance. Peer-reviewed literature published in the English language between 1955 and 2010 was reviewed using PubMed and hand searches. Since the choice of using either method of retention is still controversial, this review article offers some clinical situations that prefer one method of retention over the other. The review demonstrated that each method of retention has certain advantages and disadvantages; however, there are some clinical situations in which it is better to select one method of retention rather than the other.
Campos organizacionais: seis diferentes leituras e a perspectiva de estruturação
Authors: Machado-da-Silva Clóvis L. , Guarido Filho Edson R. , Rossoni Luciano
Published: November 2010

O conceito de campo organizacional vem sendo tratado com certo destaque na literatura sobre teoria institucional, nos últimos anos. Como o conceito de campo envolve uma dimensão relacional e outra simbólica, propomos que a teoria da estruturação, baseada na lógica de recursividade entre agência e estrutura, seja adequada para o entendimento do campo de maneira dinâmica. Nesse sentido, o objetivo do presente ensaio teórico é tratar a dinâmica do campo organizacional sob uma lógica estruturacionista, admitindo-se que a partir dela se resgata tanto a importância da prática no processo de estruturação do campo organizacional como o caráter histórico e recursivo, que tanto constrange como habilita as ações dos atores sociais. Para tanto, revisamos o conceito de campo em diferentes perspectivas de análise, refletindo sobre as implicações dos pressupostos teóricos de cada abordagem e, em seguida, discutimos criticamente a fundamentação teórica do processo de estruturação de campos organizacionais com base na abordagem estruturacionista. Concluímos o ensaio com proposições acerca da revisão do conceito de campo sob uma ótica multiparadigmática, na qual estrutura e agência estão recursivamente implicadas.