bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ba2NdZrO5.5 as a potential substrate material for YBa2Cu3O7‐δ superconducting films
Authors: Tovar H. , Ortiz Díaz O. , Landínez Téllez D. A. , Roa‐Rojas J. 
Published: October 2007

AbstractThe new oxide Ba2NdZrO5.5 (BNZO) has been produced by the standard solid state reaction method. X‐ray diffraction analysis (XRD) revealed that this synthesized material has an ordered complex cubic perovskite structure characteristic of A2BB'O6 crystalline structure with a lattice parameter of a = 8.40 Å. It was established through EDX analysis that there is no trace of impurities. Chemical stability of BNZO with YBa2Cu3O7‐δ (YBCO) has been studied by means of Rietveld analysis of experimental XRD data on several samples of BNZO‐YBCO composites. Quantitative analysis of phases on XRD patterns show that all peaks have been indexed for both BNZO and YBCO, and no extra peak is detectable. YBCO and BNZO remain as two different separate phases in the composites with no chemical reaction. Electrical measurements also revealed that superconducting transition temperature of pure YBCO and BNZO‐YBCO composites is 90 K. These favorable characteristics of BNZO show that it can be used as a potential substrate material for deposition of YBCO superconducting films. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic and structural properties of the nanostructured Fe1–xSix system with x = 0.1, 0.2 and 0.3, mechanical alloyed and sintered
Authors: Rodríguez R. R. , Pérez Alcázar G. A. , Sánchez H. , Sacilotti M. , Greneche J. M. 
Published: October 2007

AbstractThe magnetic and structural properties of the nanostructured system Fe1–xSix with x = 0.1, 0.2 and 0.3 were studied by X‐Ray diffraction (XRD), SEM, and Mössbauer Spectrometry (MS). The samples were prepared by compacting and sintering at two temperatures, 900 and 1000 °C, from powders obtained by means of two procedures: by elemental mixing of Fe and Si powders and by mechanical alloying (MA). For samples obtained from mixed powders and sintered at 900 and 1000 °C, XRD and MS show the presence of pure iron and silicon, indicating that these conditions do not favor alloying, except for the sample with 30 at.% and 1000 °C, for which, besides of iron and silicon patterns, the DO3 and FeSi phases are also evidenced. The grain sizes are approximately ranged from 24 to 40 nm for the pure iron and 43 to 90 nm for the pure silicon. For the mechanical alloyed powders, the as milled samples with 10 and 20 at.% Si consist of a bcc structure and for 30 at.% of FeSi and DO3 phases. The grain sizes are 14, 12 and 7 nm for 10, 20 and 30 at.% Si, respectively, showing that the fragility increases with silicon content and for the as sintered sample with 10 at.% Si BCC grain size is now approximately 15 nm. It is worthy to note that when sintering, the DO3, FeSi and Fe5Si3 phases are developed, while in the 30 at.% Si as sintered mixed elemental powder, only an incipient alloy is obtained. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the novel superprotonic conductor material β ‐Cs3(HSO4)2[H2‐x(P1‐x, Sx)O4)] (x ∼ 0.5): Does it behave as a solid phase?
Authors: Ortiz E. , Vargas R. A. , Tróchez J. C. , Bornacelli J. , Núñez H. 
Published: October 2007

AbstractThe high‐temperature phase transition in the novel superprotonic conductor material β ‐Cs3(HSO4)2[H2–x(P1‐x, Sx)O4)] (x ∼ 0.5) at Tp = 398 K was carefully examined by using simultaneous thermo‐gravimetric and differential thermal analysis, modulated differential thermal analysis, and impedance spectroscopy. Our results show evidence that at around this temperature the whole enthalpy‐change is due to dehydration processes that take place on the surface of the crystal and promote high protonic conductivity above this temperature. As a consequence, our findings support the hypothesis that the reported superprotonic‐conducting phase of this material above Tp probably does not exist. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron paramagnetic resonance of double perovskite Ba2FeMoO6
Authors: Hernández‐Gómez Pablo , Almanza Ovidio 
Published: October 2007

AbstractIn this work we present electron paramagnetic resonance (EPR) measurement of double perovskite Ba2FeMoO6. This type of materials are of great interest due to their simultaneous conducting and ferrimagnetic properties, being them able to use in practical devices for their giant magnetoresistance effect at room temperature The samples have been syntethized with standard ceramic route, with sintering temperature of 1200 °C in a reducing He/H2 atmosphere. EPR measurements have been carried out in a Bruker spectrometer operating in X band, in the temperature range 80 to 400 K. Below Curie temperature the single line becomes asymmetric, broadens and shifts to lower fields with decreasing temperature. In the paramagnetic region the peak‐to‐peak intensity decreases sharply and the line broadens up to 340 K. The experimental data are compared with similar results of other double perovskites analyzed previously by other authors. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization and electrical properties of new perovskite films of Ba(Ti,Zr)O3 type doped with lanthanum (BLZT)
Authors: Delgado E. , Ostos C. , Martínez‐Sarrión M. L. , Mestres L. , Prieto P. 
Published: October 2007

AbstractIn the current work, we characterized a new family of compounds with perovskite‐type structure with the general formula: Ba1–yLa2y/3Ti1–xZrxO3 (BLZT). Through XRD on crystalline powder we detected a single perovskite cubic phase, Pm3m (221), for the compounds with zirconium content (x) lower than 0.15 and lanthanum content (La) lower than 0.17. Upon increasing the x value in BLZT compounds, the value of La falls to 0.13. Morphology studies through SEM revealed that the incorporation of lanthanum into the composition of Ba(Ti,Zr)O3 (BZT) compounds produces the formation of bigger grains and materials with greater density. The stoichiometry for each compound was corroborated by atomic emission spectroscopy (AES‐ICP). The lanthanum‐doped compounds demonstrated higher relative permittivity values with respect to the BZT and a decrease of the Curie temperature (Tc) with relation to the amount of La3+ ion present in the structure. Finally, we grew thin films by using a target of the compound Ba0.90La0.067Ti0.91Zr0.09O3 over three different substrates under two atmospheres (Ar and O2), using the Magnetron Sputtering technique by Radio Frequency (RF), showing the best results when growth is over the substrate SrTiO3.Nb 0.1% in the [00l] direction under an O2 atmosphere. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure–Activity Relationships for Aldehyde Categories
Authors: Walker John D. , Printup Heather 
Published: October 2007

AbstractThe US Environmental Protection Agency (US EPA) nominated aldehydes to the Toxic Substances Control Act (TSCA) Interagency Testing Committee (ITC) to obtain aquatic toxicity data with the understanding that these data could be used to develop or improve Structure–Activity Relationships (SARs) or Quantitative Structure–Activity Relationships (QSARs) for predicting the toxicity of untested aldehydes to aquatic organisms. The Substructure‐based Computerized Chemical Selection Expert System (SuCCSES) was used to identify about 600 non‐polymeric aldehydes in the TSCA inventory of existing chemicals. After analyzing production and importation volumes and structural data for these 600 aldehydes, a database of 125 structurally diverse aldehydes was developed. SuCCSES was used to classify 125 aldehydes into substructure‐based categories. After searching for published and unpublished data, aquatic organism LC50 values were obtained for 74 of these 125 aldehydes. Fathead minnow LC50 values were used to develop SARs describing gross differences between aldehyde categories. Five figures are provided to illustrate differences between benzaldehyde and aldehydes in the substructure‐based categories and explanations are provided to describe the differences. The substructure‐based categories can be used to facilitate the review of multiple aldehydes. However, as described in the subsequent paper, different modes of action of aldehydes in the same substructure‐based category precludes the use of a category approach to predict toxicities of other aldehydes.
Characterization of the Partitioning of Gaseous Solutes Into Humic Acid with the Abraham Model and Temperature‐Independent Equation Coefficients
Authors: Mintz Christina , Ladlie Tara , Burton Katherine , Clark Michael , Acree William E. , Abraham Michael H. 
Published: October 2007

AbstractPublished gas‐to‐Leonardite humic acid partition coefficient data, measured at a relative humidity of 98% and at 278.15, 288.15, 298.15, 308.15, and 318.15 K, were correlated with the Abraham solvation parameter model. The five derived temperature‐specific correlations described the observed partition coefficient data to within an overall standard deviation of 0.33 log units. A method was devised for combining experimental partition coefficients measured at different temperatures into a single regression correlation. The proposed method described the 664 experimental partition coefficients, which covered the 278.15–348.15 K temperature interval, to within a standard deviation of 0.33 log units.
Proper inference from Simon's two‐stage designs
Authors: Koyama Tatsuki , Chen Heidi 
Published: October 2007

AbstractSimon's two‐stage designs are very popular for phase II clinical trials. A literature review revealed that the inference procedures used with Simon's designs almost always ignore the actual sampling plan used. Reported P‐values, point estimates and confidence intervals for the response rate are not usually adjusted for the design's adaptiveness. In addition, we found that the actual sample size for the second stage is often different from that planned. We present here a method for inferences using both the planned and the actual sample sizes. The conventional and the preferred inference procedures usually yield similar P‐values and confidence intervals for the response rate. The conventional inference, however, may contradict the result of the corresponding hypothesis testing. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of time to a silent event whose occurrence is monitored with error, with application to mother‐to‐child HIV transmission
Authors: Zhang Peng , Lagakos Stephen W. 
Published: October 2007

AbstractInferences about the distribution of time to HIV infection in infants are complicated because infection is a silent event and imperfect diagnostic tests are used to detect its occurrence, leading to false‐positive and false‐negative results. Nonparametric likelihood approaches are computationally hampered by a large number of parameters and a possibly nonconcave likelihood function. To overcome these difficulties, we develop one‐sample and regression methods based on profile likelihood and Markov chain Monte Carlo techniques. The methods also provide a useful diagnostic for assessing the infection status of individual subjects, and are illustrated using results from a recent clinical trial for the prevention of mother‐to‐child HIV transmission. Copyright © 2007 John Wiley & Sons, Ltd.
Covering the tsunami disaster: subsequent post‐traumatic and depressive symptoms and associated social factors
Authors: Weidmann Anke , Fehm Lydia , Fydrich Thomas 
Published: October 2007

AbstractJournalists frequently report on disasters. There is a growing evidence that they are subsequently at higher risk of post‐traumatic and depressive symptoms. We conducted an internet‐based study with 61 journalists who had covered the tsunami disaster in December 2004 from the affected region. The extent of trauma exposure, symptoms and social variables were assessed. About 8 months after the event, indications of post‐traumatic stress disorder were found in 6.6 per cent of the sample. Post‐traumatic and depressive symptoms were related to the extent of traumatic exposure and to several social variables, most importantly, a low degree of social acknowledgment by supervisor and colleagues. Copyright © 2007 John Wiley & Sons, Ltd.
Implications of bidirectional flow in the great arteries at the 11–14‐week scan
Authors: Zidere V. , Allan L. D. , Huggon I. C. 
Published: October 2007

AbstractObjectiveTo determine the implications of a bidirectional Doppler flow pattern detected in one or both of the fetal great arteries in the first trimester.MethodsDatabase records were reviewed for cases of bidirectional flow found on fetal echocardiography performed at less than 15 weeks of gestation between January 1999 and October 2006 inclusive. Bidirectional flow consisted of antegrade flow in systole and retrograde flow in diastole. Data including indication for fetal echocardiography, gestational age at diagnosis, the anatomical features, karyotype, nuchal translucency measurement and outcome were collected.ResultsFrom almost 2500 scans, bidirectional flow was detected in a total of 15 fetuses. The abnormal flow pattern was confined to the aorta in four, to the pulmonary artery in four, and was present in both great arteries in a further seven fetuses. Eight of the 15 fetuses had regurgitation at one or both atrioventricular valves. Additional cardiac abnormalities were detected by ultrasound in eight cases. Of the 13 cases for which the karyotype was known, 12 were abnormal and five of these had trisomy 18. None of the fetuses survived. There were two intrauterine deaths and 13 terminations of pregnancy.ConclusionBidirectional flow in one or both great arteries is an unusual finding at the first‐trimester scan and must be distinguished from the retrograde flow occurring only in systole in duct‐dependent heart defects. It carries a poor prognosis, which is a consequence of both the high chance of underlying chromosomal abnormality and the hemodynamic compromise associated with severe arterial valve regurgitation. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Long‐term β‐adrenergic stimulation leads to downregulation of protein phosphatase inhibitor‐1 in the heart
Authors: El‐Armouche Ali , Gocht Fabian , Jaeckel Elmar , Wittköpper Katrin , Peeck Micha , Eschenhagen Thomas 
Published: October 2007

AbstractDesensitization of the β‐adrenoceptor/cAMP/PKA pathway is a hallmark of heart failure. Inhibitor‐1 (I‐1) acts as a conditional amplifier of β‐adrenergic signalling downstream of PKA by inhibiting type‐1 phosphatases in the PKA‐phosphorylated form. I‐1 is downregulated in failing hearts and thus presumably contributes to β‐adrenergic desensitization. To test whether I‐1 downregulation is a consequence of excessive adrenergic drive in heart failure, rats were treated via minipumps with isoprenaline 2.4mg/kg/day (ISO) or 0.9% NaCl for 4days. As expected, chronic ISO increased heart‐to‐body weight ratio by ~40% and abolished the inotropic response to acute ISO in papillary muscles by ~50%. In the ISO‐treated hearts I‐1 mRNA and protein levels were decreased by 30% and 54%, respectively. This was accompanied by decreased phospholamban phosphorylation (−40%), a downstream target of I‐1, and a reduction in 45Ca2+ uptake (−54%) in membrane vesicles. Notably, phospholamban phosphorylation correlated significantly with I‐1 protein levels indicating a causal relationship. We conclude that I‐1 downregulation in heart failure is likely a consequence of the increased sympathetic adrenergic drive and participates in desensitization of the β‐adrenergic signalling cascade.
Plasmodiumin the placenta: parasites, parity, protection, prevention and possibly preeclampsia
Authors: DUFFY PATRICK E. 
Published: October 2007

SUMMARYThe epidemiology of pregnancy malaria infection and disease is complex but reflects underlying interactions between thePlasmodium falciparumparasite, the mother, and the foetus. Parasites sequester in the human placenta by binding to chondroitin sulfate A (CSA), a novel receptor that does not commonly support binding of other parasites. Women become resistant toP. falciparummalaria over successive pregnancies as they acquire antibodies against the CSA-binding placental parasite forms. Due to acquired immunity, placental malaria is briefer and less inflammatory in multigravid women than primigravid women, and these parity differences may account for the different outcomes these women and their offspring experience. Commonly recognized sequelae of malaria-like maternal anaemia and low birth weight primarily occur in first and second pregnancies. Hypertension may result from maternal-foetal conflict over the inflammatory response to placental malaria, and occurs in young, first-time mothers. Placental malaria can either increase or decrease parasitaemia risk in the offspring, depending on the mother's parity. The burden of disease due to pregnancy malaria, and the benefits of an effective vaccine, may be much greater than is currently appreciated.
Protozoan and helminth infections in pregnancy. Short-term and long-term implications of transmission of infection from mother to foetus
Authors: PETERSEN ESKILD 
Published: October 2007

SUMMARYThis review of protozoan and helminth infections in pregnancy focuses on the impact on the immune response in the newborn infant to maternal infection. Studies of protozoan and helminth infections in pregnant women and in their offspring have shown that children exposed to antigens or microorganisms during pregnancy often have a reduced immune response to these infections. The most common finding is a reduced IFNγ response to specific antigens regardless of specific infection studied. In some studies the impaired immune response disappeared before the age of one year, while in other studies the impaired immune response was present as much as two decades after birth. Data from chronic viral infections like Rubella, cytomegalovirus and hepatitis B also show that congenital or perinatal infections may result in a life-long inability to control the infections. Studies of both helminth and protozoan infections show that children exposed to antigens during gestation have a microorganism-specific impaired immune response which is characterized by reduced IFN-γ and stimulation of responses to specific antigens.
Cellular and molecular physiopathology of congenital toxoplasmosis: The dual role of IFN-γ
Authors: PFAFF A. W. , ABOU-BACAR A. , LETSCHER-BRU V. , VILLARD O. , SENEGAS A. , MOUSLI M. , CANDOLFI E. 
Published: October 2007

SUMMARYToxoplasma gondiiis one of the few pathogens that can cross the placenta. Frequency and severity of transmission vary with gestational age. While the control of acquired toxoplasmosis is already well explored, the control of materno-foetal transmission of the parasite remains almost unknown. This is partly due to the lack of an animal model to study this process. This review summarises the studies which have been undertaken and shows that the mouse is a valuable model despite obvious differences to the human case. The paramount role of the cellular immune response has been shown by several experiments. However, IFN-γ has a dual role in this process. While its beneficial effects in the control of toxoplasmosis are well known, it also seems to have transmission-enhancing effects and can also directly harm the developing foetus. The ultimate goal of these studies is to develop a vaccine which protects both mother and foetus. Therefore, it is useful to study the mechanisms of natural resistance against transmission during a secondary infection. In this setting, the process is more complicated, involving both cellular and also humoral components of the immune system. In summary, even if the whole process is far from being elucidated, important insights have been gained so far which will help us to undertake rational vaccine research.
Parent and child perspectives on physician communication in pediatric palliative care
Authors: Hsiao Jennifer L. , Evan Elana E. , Zeltzer Lonnie K. 
Published: October 2007

ABSTRACTObjective:Despite growing recognition of the importance of communication with children with life-limiting illnesses and their families, there has been limited research that includes the child's perspective. The purpose of the current study was to identify the aspects of physician communication that children with life-limiting illnesses and their parents perceived to be facilitative or obstructive in pediatric palliative care.Methods:This qualitative study reports on the first 20 parent and child pairs of pediatric oncology and cardiology patients (mean age 14.25 years, range 9-21 years) with a poor prognosis (physician reported likely <20% chance of survival beyond 3 years) from two children's hospitals and one pediatric hospice in Los Angeles, California. Perspectives on physician communication were elicited from children's and parents' individual narratives, recorded, coded, and analyzed using qualitative grounded theory methodology.Results:Both children and parents identified five domains of physician communication deemed to be highly salient and influential in quality of care. These included relationship building, demonstration of effort and competence, information exchange, availability, and appropriate level of child and parent involvement. Parents identified coordination of care as another important communication domain. The characteristics of physicians that were deemed most harmful to satisfying communication included having a disrespectful or arrogant attitude, not establishing a relationship with the family, breaking bad news in an insensitive manner, withholding information from parents and losing their trust, and changing a treatment course without preparing the patient and family.Significance of results:The six positive communication domains are areas for clinicians to recognize and monitor in communicating with children and families in the pediatric palliative care setting. Knowledge of the qualities of communication that are satisfying to and valued by children and their parents have the potential to lead to more effective communication around the difficult decisions faced by physicians, parents, and children with life-threatening conditions.
Facing uncertainty: The lived experience of palliative care
Authors: Mckechnie Roz , Macleod Rod , Keeling Sally 
Published: October 2007

ABSTRACTObjective:This qualitative research study listens to the narratives of people experiencing the dying process who attended the Otago Community Hospice, Dunedin, New Zealand.Methods:Ten people, aged between 51 and 65, were approached; two declined and one died sooner than expected. All were women (although this was not part of the original design) and all had carcinoma. Data for the study was sought through qualitative research interviews, considering the development of each participant's illness in relation to her perception of her embodiment in the palliative care setting, and concluding with questions about what she wants the people who care for and about her to learn from her experience. Consistent with this phenomenological approach, the method of analysis was thematic and interpretive.Results:The main theme was the uncertainty that all participants felt throughout the diagnostic process and during treatment. Uncertainty, too, was a factor in how they managed their day, whether they would be able to sustain an outing or an activity or not and whether they would be pain free. None were afraid of dying but hoped that when they did die, they would do so comfortably. The relationship with their general practitioners varied. Where fatigue or the effects of medication were not an issue, they could think clearly, but their bodies were experienced as letting them down and limiting their activities. The ideal of “living until you die” was not able to be fulfilled. The increasing approach of social death as they withdrew from their employment and social responsibilities affected them.Significance of results:Whether one has a “good death” or not is determined not only by the progression and management of the disease process by health professionals, but also by the way in which one is perceived, by self and others. There are no guidelines for the dying role; everybody dies differently and individually.