bluuebunny/crossref_metadata_2025 huggingface dataset:
Nursing intervention studies on patients and family members: a systematic literature review
Authors: Mattila Elina , Leino Kaija , Paavilainen Eija , Åstedt‐Kurki Päivi
Published: June 2009

The development of evidence‐based practice is a major current challenge in the fields of nursing practice and nursing research. A concerted effort is needed to develop and test interventions and to assess their impacts. The illness of one family member inevitably affects other family members and the whole family. Nursing interventions should be so designed that they support and enhance the life situation of both patients and their families. The aim of this study is to undertake a systematic review of nursing intervention studies on patients and family members published in international databases in 2001–2006. The main focus was on the targets, methods and impacts of interventions. The articles for the review were searched from Medline and Cinahl (n = 31) and analysed by content analysis and the RE‐AIM evaluation model. The results showed that the interventions were targeted at patients with chronic diseases and individual family members. In addition to support components, the interventions included elements of teaching, counselling and education. The preliminary evidence indicated that the interventions were effective in relieving the burden of care and depressive symptoms of family members of Alzheimer, cancer, stroke and schizophrenia patients as well as in promoting their quality of life and coping. Nursing interventions are still in the development and testing phase. The challenge for the future is to broaden the scope and application of interventions in different nursing environments. Assessments of the efficacy of interventions should also consider their adaptation, implementation and maintenance in practical nursing.
AN ASSESSMENT OF VARIABILITY IN THEROPOD DINOSAUR REMAINS FROM THE BATHONIAN (MIDDLE JURASSIC) OF STONESFIELD AND NEW PARK QUARRY, UK AND TAXONOMIC IMPLICATIONS FORMEGALOSAURUS BUCKLANDIIANDILIOSUCHUS INCOGNITUS
Authors: BENSON ROGER B. J.
Published: June 2009

Abstract: The assemblage of large‐bodied theropod remains from the Taynton Limestone Formation (middle Bathonian) of Stonesfield, Oxfordshire and the Chipping Norton Limestone Formation (lowest Bathonian) of New Park Quarry, Gloucestershire, UK is interpreted as monospecific. An assessment of morphological variation in theropod fossils from these localities reveals no taxonomically‐significant variation among remains representing large‐bodied individuals. Previous observations of anatomical variation among femora, ilia and scapulocoracoids are attributed topostmortemdamage and deformation. Referral of all such material to the first named dinosaur taxon,Megalosaurus bucklandiiMantell, is therefore justified. ‘Iliosuchus incognitus’ lacks autapomorphies and is anomen dubium. However, other remains of small‐bodied theropods from Stonesfield indicate a minimum of two small‐bodied taxa that are distinct fromM. bucklandii.
Provider Monitoring and Pay‐for‐Performance When Multiple Providers Affect Outcomes: An Application to Renal Dialysis
Authors: Hirth Richard A. , Turenne Marc N. , Wheeler John R.C. , Pan Qing , Ma Yu , Messana Joseph M.
Published: June 2009

Objective. To characterize the influence of dialysis facilities and nephrologists on resource use and patient outcomes in the dialysis population and to illustrate how such information can be used to inform payment system design.

Data Sources. Medicare claims for all hemodialysis patients for whom Medicare was the primary payer in 2004, combined with the Medicare Enrollment Database and the CMS Medical Evidence Form (CMS Form 2728), which is completed at onset of renal replacement therapy.

Study Design. Resource use (mainly drugs and laboratory tests) per dialysis session and two clinical outcomes (achieving targets for anemia management and dose of dialysis) were modeled at the patient level with random effects for nephrologist and dialysis facility, controlling for patient characteristics.

Results. For each measure, both the physician and the facility had significant effects. However, facilities were more influential than physicians, as measured by the standard deviation of the random effects.

Conclusions. The success of tools such as P4P and provider profiling relies upon the identification of providers most able to enhance efficiency and quality. This paper demonstrates a method for determining the extent to which variation in health care costs and quality of care can be attributed to physicians and institutional providers. Because variation in quality and cost attributable to facilities is consistently larger than that attributable to physicians, if provider profiling or financial incentives are targeted to only one type of provider, the facility appears to be the appropriate locus.
Collecting Patient Race/Ethnicity and Primary Language Data in Ambulatory Care Settings: A Case Study in Methodology
Authors: Palaniappan Latha P. , Wong Eric C. , Shin Jessica J. , Moreno Maria R. , Otero‐Sabogal Regina
Published: June 2009

Objective. To collect patient race/ethnicity and language (r/e/l) in an ambulatory care setting.

Data Sources/Study Setting. The Palo Alto Medical Foundation (PAMF), December 2006–May 2008.

Study Design. Three pilot studies: (1) Comparing mail versus telephone versus clinic visit questionnaire distribution; (2) comparing the front desk method (FDM) versus exam room method (ERM) in the clinic visit; and (3) determining resource allocation necessary for data entry.

Data Collection/Extraction Methods. Studies were planned and executed by PAMF's Quality and Planning division.

Principal Findings. Collecting r/e/l data during clinic visits elicited the highest response rate. The FDM yielded higher response rate than the ERM. One full‐time equivalent is initially necessary for data entry.

Conclusions. Conducting sequential studies can help guide r/e/l collection in a short time frame.
Potential Effects of the United States‐Mexico Border Fence on Wildlife
Authors: FLESCH AARON D. , EPPS CLINTON W. , CAIN III JAMES W. , CLARK MATT , KRAUSMAN PAUL R. , MORGART JOHN R.
Published: June 2009

Abstract: Security infrastructure along international boundaries threatens to degrade connectivity for wildlife. To explore potential effects of a fence under construction along the U.S.–Mexico border on wildlife, we assessed movement behavior of two species with different life histories whose regional persistence may depend on transboundary movements. We used radiotelemetry to assess how vegetation and landscape structure affect flight and natal dispersal behaviors of Ferruginous Pygmy‐Owls (Glaucidium brasilianum), and satellite telemetry, gene‐flow estimates, and least‐cost path models to assess movement behavior and interpopulation connectivity of desert bighorn sheep (Ovis canadensis mexicana). Flight height of Pygmy‐Owls averaged only 1.4 m (SE 0.1) above ground, and only 23% of flights exceeded 4 m. Juvenile Pygmy‐Owls dispersed at slower speeds, changed direction more, and had lower colonization success in landscapes with larger vegetation openings or higher levels of disturbance (p≤ 0.047), which suggests large vegetation gaps coupled with tall fences may limit transboundary movements. Female bighorn sheep crossed valleys up to 4.9 km wide, and microsatellite analyses indicated relatively high levels of gene flow and migration (95% CI forFST=0.010–0.115, Nm = 1.9–24.8,M =10.4–15.4) between populations divided by an 11‐km valley. Models of gene flow based on regional topography and movement barriers suggested that nine populations of bighorn sheep in northwestern Sonora are linked by dispersal with those in neighboring Arizona. Disruption of transboundary movement corridors by impermeable fencing would isolate some populations on the Arizona side. Connectivity for other species with similar movement abilities and spatial distributions may be affected by border development, yet mitigation strategies could address needs of wildlife and humans.
Testing platelet mass versus platelet count to guide platelet transfusions in the neonatal intensive care unit
Authors: Gerday Erick , Baer Vickie L. , Lambert Diane K. , Paul David A. , Sola‐Visner Martha C. , Pysher Theodore J. , Christensen Robert D.
Published: June 2009

BACKGROUND: Platelet (PLT) transfusions can bestow significant benefits but they also carry risks. This study sought a safe means of reducing PLT transfusions to neonatal intensive care unit (NICU) patients with thrombocytopenia by comparing two transfusion guidelines, one based on PLT count and the other on PLT mass (PLT count times mean PLT volume).

STUDY DESIGN AND METHODS: Using a prospective, two‐centered, before versus after design, PLT transfusion usage and hemorrhagic events were contrasted during a period when PLT count–based transfusion guidelines were in use (Period 1) versus a period when PLT mass–based guidelines were in use (Period 2).

RESULTS: No differences were observed between Periods 1 and 2 in NICU admissions, sex, race/ethnicity, percentage of inborn patients, or percentage of patients with a PLT count less than 50 × 109 or 51 × 109 to 99 × 109/L. In the first period 3.6% of NICU admissions received one or more PLT transfusions. This fell to 1.9% during the second period (p < 0.002). The number of PLT transfusions administered per transfused patient was the same in both periods: 2.0 (1‐23) (median [range]) in Period 1 and 2.0 (1‐17) in Period 2 (p > 0.40). Significantly fewer PLT transfusions were given in Period 2 for prophylaxis (patient not bleeding; p < 0.001 vs. Period 1). The number given for bleeding did not change between the two periods. In Period 2 no increases were seen in rate of intraventricular hemorrhage (IVH); Grade 3 or 4 IVH; or pulmonary, gastrointestinal, or cutaneous bleeding.

CONCLUSIONS: The use of PLT mass–based NICU transfusion guidelines was associated with fewer PLT transfusions and no recognized increase in hemorrhagic problems.
Trehalose inhibited the phagocytosis of refrigerated platelets in vitro via preventing apoptosis
Authors: Liu Qi , Xu Lin , Jiao Shu‐xian , Wang Tong‐xian , Song Yi , Wen Zhen‐ke
Published: June 2009

BACKGROUND: The sole reason that platelets (PLTs) are currently stored at room temperature is that refrigeration of PLTs results in their rapid clearance after transfusion. Recent data have suggested that trehalose was an effective cryoprotective reagent for human PLTs. This study evaluated the effect of trehalose on the phagocytosis of refrigerated PLTs.

STUDY DESIGN AND METHODS: Phagocytosis of PLTs was evaluated with THP‐1 cells. Phosphatidylserine exposure and caspase‐3 activity in PLTs were measured with flow cytometry. PLT mitochondrial transmembrane potentials were studied by staining PLTs with JC‐1. Expression of Bcl‐XL and Bax was determined by Western blot. PLT aggregation was studied in vitro with a PLT aggregation profiler.

RESULTS: It was demonstrated that trehalose significantly inhibited the phagocytosis of refrigerated PLTs by showing that the phagocytotic ratio of PLTs refrigerated with trehalose for 9 days was generally comparable with that of PLTs stored at room temperature for 5 days, which was significantly lower than that of PLTs refrigerated without trehalose. Further studies revealed that trehalose could prevent the apoptosis of refrigerated PLTs, which was determined by the phosphatidylserine exposure, caspase‐3 activities, mitochondrial transmembrane potentials, and expression of Bcl‐XL and Bax. Finally, it was shown that PLTs refrigerated with trehalose for 9 days also maintained their activity to aggregate when exposed to agonists in a standard aggregometry assay.

CONCLUSION: Our results suggest that trehalose could inhibit the phagocytosis of refrigerated PLTs in vitro through preventing apoptosis, implying that trehalose is a promising candidate to optimize the refrigeration of human PLTs.
Easy identification of antibodies to high‐prevalence Scianna antigens and detection of admixed alloantibodies using soluble recombinant Scianna protein
Authors: Seltsam Axel , Grueger Daniela , Blasczyk Rainer , Flegel Willy A.
Published: June 2009

BACKGROUND: Identification of antibodies against high‐prevalence Scianna (Sc; ERMAP) antigens, like Sc1 and Sc5, is difficult and may incur delays in blood procurement and costs. The detection of additional clinically significant alloantibodies is hampered in the presence of anti‐Scianna. Soluble recombinant Scianna protein is demonstrated to facilitate antibody diagnostics in both cases.

STUDY DESIGN AND METHODS: Soluble recombinant Scianna protein (Sc:1,‐2,3,‐4,5,6,7) was produced comprising the antigenic extracellular domain fused to a V5‐His tag. The protein was isolated from eukaryotic cell culture supernatants of stably transfected HEK293 cells. Seven serum samples with anti‐Sc1, anti‐Sc2, and anti‐Sc5 and 30 serum samples with antibodies to other blood group antigens were evaluated in hemagglutination inhibition assays. Antisera with mixed antibody specificities and autoantibodies were also tested.

RESULTS: Soluble Scianna protein inhibited specifically antibodies to the high‐prevalence Scianna antigens Sc1 and Sc5. No antibodies were neutralized that were directed to the low‐prevalence Sc2 antigen or to a large representative set of antigens from other blood group systems. Clinically relevant antibodies could be identified despite being masked by anti‐Sc1 and anti‐Sc5. A mixture of Scianna and JMH proteins allowed detecting a common antibody despite the presence of antibodies to high‐prevalence antigens of the Scianna or JMH blood group systems.

CONCLUSION: Antibody detection systems comprising soluble recombinant Scianna protein provide an easy single‐step method for detection and identification of antibodies to high‐prevalence Scianna antigens. Reagents with Scianna and other recombinant blood group proteins and mixtures of such proteins would be useful routine reagents in immunohematology.
Blood salvage use in gynecologic oncology
Authors: Nagarsheth Nimesh P. , Sharma Tarun , Shander Aryeh , Awan Ahsan
Published: June 2009

BACKGROUND: Blood salvage allows for collection and processing of surgical blood loss with the eventual reinfusion of washed red blood cells (RBCs) back to the patient. The use of blood salvage in patients undergoing surgery for malignancy is off‐label. Controversy exists as to the risk of potential cancer dissemination resulting from the reinfusion of the processed blood, but no data are available to confirm this risk. Recent studies have demonstrated that filtering the salvaged blood using a leukoreduction filter (LRF) significantly decreases the number of cancer cells in the recovered RBC aliquot in a variety of cancer types.

STUDY DESIGN AND METHODS: Patients on the gynecologic oncology service as part of the bloodless surgery program at Englewood Hospital and Medical Center from April 1998 to April 2007 were identified. Three patients that had reinfusion of cell salvage blood (all reinfusions were performed after filtration with a LRF) were studied further with emphasis placed on long‐term outcomes.

RESULTS: Two of the three patients did not show any evidence of metastases after surgery. The only patient that developed evidence of hematogenous progression had known liver metastases at the time of her initial diagnosis and therefore had hematogenous dissemination before her index surgery.

CONCLUSION: In this series of patients undergoing surgery for malignancies on the gynecologic oncology service, blood salvage with LRF was not definitively associated with hematogenous dissemination. Further large controlled studies are needed to demonstrate the clinical safety of the use of blood salvage in this setting.
Minority and foreign‐born representation among US blood donors: demographics and donation frequency for 2006
Authors: Murphy Edward L. , Shaz Beth , Hillyer Christopher D. , Carey Patricia , Custer Brian S. , Hirschler Nora , Fang Junyong , Schreiber George B.
Published: June 2009

BACKGROUND: Historically, minority populations have represented only a small proportion of US blood donors, but recent trends in immigration and potential blood shortages emphasize the need for recruitment strategies to increase minority donations.

STUDY DESIGN AND METHODS: Donation data from a network of six US blood centers for 2006 were analyzed. Race/ethnicity, country of birth, and educational attainment data were collected specifically for the study and assessed for their influence on donation behavior. Logistic regression was used to determine independent associations with repeat donors status and annual donation frequency.

RESULTS: A total of 1,288,998 donations from 729,068 donors were studied; most donors had data on race/ethnicity (97.1%) and country of birth (93.1%). The proportion of minority donors differed by blood center, with African American donors (16%) most common at the Southeastern blood center and Asian (12%), Hispanic (13%), and foreign‐born donors (13%) most common at the Northern California blood center. Minority donors and those born in Mexico or Latin America were younger than white donors. Minority and non–US‐born donors were less likely than white and US‐born donors to be repeat donors (odds ratio [OR], 0.60‐0.78), and most were less likely to give two or more annual donations (OR, 0.82‐1.11).

CONCLUSION: Minority and Mexico/Latin America–born donors represent a younger and often first‐time donor population compared to white and US‐born donors, but their annual donation frequency was only slightly lower than white and US‐born donors. Increasing the retention and donation frequency of minorities will be important for supplementing the blood supply.
The Democratic Domino Theory: An Empirical Investigation
Authors: Leeson Peter T. , Dean Andrea M.
Published: June 2009

According to the democratic domino theory, increases or decreases in democracy in one country spread and “infect” neighboring countries, increasing or decreasing their democracy in turn. Using spatial econometrics and panel data that cover over 130 countries between 1850 and 2000, this article empirically investigates the democratic domino theory. We find that democratic dominoes do in fact fall as the theory contends. However, these dominoes fall significantly “lighter” than the importance of this model suggests. Countries “catch” only about 11% of the increases or decreases in their average geographic neighbors’ increases or decreases in democracy. This finding has potentially important foreign policy implications. The “lightness” with which democratic dominoes fall suggests that even if foreign military intervention aimed at promoting democracy in undemocratic countries succeeds in democratizing these nations, intervention is likely to have only a small effect on democracy in their broader regions.
Learning to Cooperate: Learning Networks and the Problem of Altruism
Authors: Scholz John T. , Wang Cheng‐Lung
Published: June 2009

We explore how two populations learn to cooperate with each other in the absence of institutional support. Individuals play iterated prisoner's dilemmas with the other population, but learn about successful strategies from their own population. Our agent‐based evolutionary models reconfirm that cooperation can emerge rapidly as long as payoffs provide a selective advantage for nice, retaliatory strategies like tit‐for‐tat, although attainable levels of cooperation are limited by the persistence of nonretaliatory altruists. Learning processes that adopt the current best response strategy do well only when initial conditions are very favorable to cooperation, while more adaptive learning processes can achieve high levels of cooperation under a wider range of initial conditions. When combined with adaptive learning, populations having larger, better connected learning relationships outperform populations with smaller, less connected ones. Clustered relationships can also enhance cooperation, particularly in these smaller, less connected populations.
Bargaining in the Shadow of War: When Is a Peaceful Resolution Most Likely?
Authors: Wittman Donald
Published: June 2009

This article derives the optimal bargaining strategies of the belligerents when each side has private but incomplete information about the expected outcome of a war, should it take place. I show that the aggressor's demand curve can be below the defender's offer curve, that wars are possible even when both sides are jointly pessimistic, and that the relative cost of a war can radically alter the types of disputes that end in war. A simple diagram provides the intuition for most of the major propositions.
Punctuated Equilibrium in Comparative Perspective
Authors: Baumgartner Frank R. , Breunig Christian , Green‐Pedersen Christoffer , Jones Bryan D. , Mortensen Peter B. , Nuytemans Michiel , Walgrave Stefaan
Published: June 2009

We explore the impact of institutional design on the distribution of changes in outputs of governmental processes in the United States, Belgium, and Denmark. Using comprehensive indicators of governmental actions over several decades, we show that in each country the level of institutional friction increases as we look at processes further along the policy cycle. Assessing multiple policymaking institutions in each country allows us to control for the nature of the policy inputs, as all the institutions we consider cover the full range of social and political issues in the country. We find that all distributions exhibit high kurtosis values, significantly higher than the Normal distribution which would be expected if changes in government attention and activities were proportionate to changes in social inputs. Further, in each country, those institutions that impose higher decision‐making costs show progressively higher kurtosis values. The results suggest general patterns that we hypothesize to be related to boundedly rational behavior in a complex social environment.
China's Local Political Budget Cycles
Authors: Guo Gang
Published: June 2009

This article examines the political budget cycles in Chinese counties. The shift to a more performance‐based cadre evaluation and mobility system during the reform era has created an incentive structure for local leaders to increase government spending at strategically important time points during their tenure to enhance the prospect of official promotion. Such expenditures help local leaders to impress their superiors with economic and political achievements, especially those visible and quantifiable large‐scale development projects. At the same time, economic and fiscal decentralization increased the capacity of local leaders to influence government budget expenditures as the need rises. The hypothesized curvilinear relationship between a leader's time in office and increased spending was tested using a comprehensive data set of all Chinese counties from 1997 through 2002. The panel data analysis shows that growth in local government spending per capita is the fastest during a leader's third and fourth years in office.
Balancing Regionalism and Localism: How Institutions and Incentives Shape American Transportation Policy
Authors: Gerber Elisabeth R. , Gibson Clark C.
Published: June 2009

Public policy decisions are increasingly made byregional governance effortsthat involve diverse decision makers from multiple government units within a geographic region. These decision‐making bodies face competing pressures to represent regional and local interests. We study how decision makers balance preferences for regionalism and localism withinmetropolitan planning organizations(MPOs), the policymaking entities that are responsible for implementing U.S. federal surface transportation policy at the regional level. Our model of regional governance relates variation in regional policy outcomes to the incentives of MPO decision makers and the institutional environments in which they interact. Analyzing data from a sample of the nation's largest metropolitan areas, we find that MPOs dominated by elected officials produce more locally focused policies, holding other factors constant, while MPOs dominated by nonelected public managers produce more regionally oriented policies. Contextual factors, as well as the regional governance institutions themselves, further shape the balance between regionalism and localism.
Does Gerrymandering Cause Polarization?
Authors: McCarty Nolan , Poole Keith T. , Rosenthal Howard
Published: June 2009

Both pundits and scholars have blamed increasing levels of partisan conflict and polarization in Congress on the effects of partisan gerrymandering. We assess whether there is a strong causal relationship between congressional districting and polarization. We find very little evidence for such a link. First, we show that congressional polarization is primarily a function of the differences in how Democrats and Republicans represent the same districts rather than a function of which districts each party represents or the distribution of constituency preferences. Second, we conduct simulations to gauge the level of polarization under various “neutral” districting procedures. We find that the actual levels of polarization are not much higher than those produced by the simulations. We do find that gerrymandering has increased the Republican seat share in the House; however, this increase is not an important source of polarization.
Presidential Saber Rattling and the Economy
Authors: Wood B. Dan
Published: June 2009

Saber rattling is a prominent tool of the U.S. president's foreign policy leadership. Yet there has been no study of how presidential saber rattling affects international or domestic political outcomes. This study evaluates how presidential saber rattling affects U.S. economic behavior and performance. Theoretically, the study demonstrates that presidential rhetoric affects the risks that economic actors are willing to take, as well as the consequences of these resulting behaviors for U.S. economic performance. Using monthly time series running from January 1978 through January 2005, vector autoregression methods are applied to show that increased presidential saber rattling produces increased perceptions of negative economic news, declining consumer confidence, lower personal consumption expenditures, less demand for money, and slower economic growth. More broadly, the study demonstrates an important linkage between the president's two most important roles: foreign and economic policy leadership. The president's foreign policy pronouncements not only impact other nations, but also affect domestic economic outcomes.
What Small Spatial Scales Are Relevant as Electoral Contexts for Individual Voters? The Importance of the Household on Turnout at the 2001 General Election
Authors: Cutts David , Fieldhouse Edward
Published: June 2009

For many years, scholars of voting behavior have been thwarted in their attempts to identify micro spatial variations in turnout by data limitations. This has meant that most analyses have been ecological, which has implications for valid inference. Here, for the first time, a hierarchical approach is used to show the relative importance of several micro spatial scales, including the household, on voter participation. The findings highlight the importance of the household context. While those who live together often turn out together, the relative level of clustering within households as opposed to between geographical areas is found to be more important for two‐person households compared to other households. Even after taking account of whether individuals are likely to self‐select others from similar social backgrounds or with similar political attitudes, there is strong evidence of large and significant household effects on voter participation.
Linearization of Master Sintering Curve
Authors: Blaine Deborah C. , Park Seong‐Jin , German Randall M.
Published: June 2009

The master sintering curve (MSC) is a simple and functional sinter model that is used to describe the densification of a particulate material during sintering when one sintering mechanism is dominant. Usually the MSC is expressed mathematically by a sigmoid relationship between the natural logarithm of the work of sintering and the relative density. The work of sintering is an integral term that includes the time and temperature path followed by the material during sintering as well as the apparent activation energy for densification of the material. In this work, the sigmoid form of the MSC is linearized by relating the natural logarithm of the work of sintering to the densification parameter. Linearization of the MSC simplifies the characterization of the model parameters. This is illustrated by example of different powder metal systems, showing how the linearized MSC model parameters can be easily determined directly from the plotted experimental data.
Evolution of Sintering Anisotropy Using a 2D Finite Difference Method
Authors: Cannon W. Roger , Raj P. Markondeya
Published: June 2009

A 2D finite difference method was applied to a model of aligned elliptical particles to determine why experimentally the percentage anisotropy varied with sintering strain. The results of the model showed the percentage anisotropy versus sintering shrinkage followed the trends of experimental results. The shape of the curve was affected both by the eccentricity of the ellipses and by the ratio of the grain‐boundary diffusion coefficient to the surface diffusion coefficient. The shape of the curves were dominated by the ratio of the length of grain boundary in the direction of the major axis of the ellipse to that the grain‐boundary length in the direction of the minor axis of the ellipse. The change in curvature profile near the triple point had some influence but was not as effective in explaining this trend.
Effect of Initial Particle and Agglomerate Size on the Elastic Moduli of Porous Yttria (Y2O3)
Authors: Yeheskel Ori , Shokhat Menashe , Salhov Shai , Tevet Ofer
Published: June 2009

The present study shows the effect of porosity on the dynamic elastic moduli of partially dense yttria (Y2O3). This article reveals that the sound velocities and the elastic moduli of the porous samples depend not only on density, but also upon the reciprocal of the initial particle and agglomerate size. These findings explain some of the variation in the elastic moduli found especially, but not only, for highly porous yttria.
Microstructural Evolution During Sintering with Control of the Interface Structure
Authors: Kang Suk‐Joong L. , Lee Min‐Gon , An Se‐Min
Published: June 2009

This paper reports recent theoretical perspectives and experimental results on microstructural evolution during sintering in terms of the interface structure, which is either rough (atomically disordered) or faceted (atomically ordered). The paper presents theoretical predictions and calculations of grain growth during liquid‐phase sintering based on crystal growth theories. It is shown that various types of grain growth behavior, which may be normal, abnormal, or stagnant, can appear as a result of the coupling effects of the maximum driving force for growth and the critical driving force for appreciable growth. The predictions are also shown to be valid in the case of solid‐state sintering. A number of experimental observations showing the effect of some critical processing parameters have been found to be in excellent agreement with the predictions. Principles of microstructure development (grain growth control) during sintering are suggested. In addition, the effect of the interface structure on densification is briefly described and discussed.
Synthesis, Sintering, and Microwave Dielectric Properties of KTaO3 Ceramics
Authors: Axelsson Anna‐Karin , Pan Yuya , Valant Matjaz , Alford Neil
Published: June 2009

Studies of a synthesis of KTaO3 displayed a two‐step reaction path with the intermediate formation of K2Ta4O11. Thermal and X‐ray diffraction analysis showed that the synthesis is completed at 900°C. Sintering studies showed that KTaO3 powder can produce single phase ceramics with 85% of relative density with the addition of 5% of potassium excess when sintered at 1330°C for 1 h. Longer sintering times or higher temperatures result in enhanced potassium loss and consequent formation of K6Ta10.8O30 secondary phase with tetragonal tungsten bronze structure. Room‐ and low‐temperature microwave dielectric properties of KTaO3 ceramics compare well with measurements performed on single crystals. We evaluated the influence of microstructural features (porosity, structural defects, secondary phases) on the dielectric properties of the ceramic samples.
Reducing the Photocatalytic Activity of Zinc Oxide Quantum Dots by Surface Modification
Authors: Wang Jinfeng , Tsuzuki Takuya , Sun Lu , Wang Xungai
Published: June 2009

The use of zinc oxide (ZnO) nanoparticles as ultraviolet (UV) absorbers for many organic substrates is limited because of the high photocatalytic activity of ZnO. In this study, a facile and efficient technique for the preparation of a hybrid material of silica‐coated ZnO nanoparticles was used to reduce the photocatalytic activity of ZnO. Monodispersed ZnO nanopartcles were prepared by wet chemistry and the particle surface was modified by tetraethylorthosilicate to form a silica coating via the Stöber method. ZnO samples, both before and after the coating process, were investigated by transmission electron microscopy, X‐ray diffraction, dynamic light scanning, infrared, and UV‐Vis absorption spectroscopy. The effect of the surface modification on the photocatalytic activity of ZnO was studied by monitoring the degradation of Rhodamine B caused by photo‐generated free radicals. The results implied that the photo‐generation of free‐radicals was strongly quenched by the presence of silica on the particle surface.
Melting and Interface Reaction of Mn–Si–O Glass on BaTiO3
Authors: Lin Jerry C. C. , Wei W. C. J.
Published: June 2009

A glass with the eutectic composition 3MnO1.5–2SiO2 was used to simulate the formation of a liquid phase during sintering of BaTiO3. Two oxide additives (Mn2O3 and SiO2) performing various functions of the properties of BaTiO3 were investigated for their crystallization and thermal characteristics at temperatures ≤1400°C. The wetting behavior of the glass, the dissolution of BaTiO3 in glass melt, the identification of newly formed phases, and the sequential reaction kinetics of the glass/BaTiO3 system, especially when isothermally treated at 1150°C, were investigated by electron microscopy with quantitative X‐ray energy dispersive spectroscopic (Q‐EDS) analysis. The evolution of the interfacial reaction of the glass/BaTiO3 at 1150°C is reported and discussed.
Processing and Properties of Eu3+:LiTaO3 TransparentGlass–Ceramic Nanocomposites
Authors: Tarafder Anal , Annapurna Kalyandurg , Chaliha Reenamoni Saikia , Tiwari Vidya Sagar , Gupta Pradeep Kumar , Karmakar Basudeb
Published: June 2009

We report here the processing and properties of transparent glass and glass–ceramic nanocomposites in the Li2O–Ta2O5–SiO2–Al2O3 system in the presence of Eu2O3 as luminescent probe. The formation of the LiTaO3 crystal phase, the crystallite size, and the morphology with the progression of heat treatment have been examined by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transformed infrared reflectance spectroscopy measurements. The crystallite sizes obtained from XRD and TEM are found to increase with heat‐treatment time and vary in the range of 2–20 nm. The measured photoluminescence spectra exhibit emission transitions of 5D0,1→7Fj (j=0, 1, 2, 3, and 4) of Eu3+ ions. From the nature of the emission transitions, the site symmetry in the vicinity of Eu3+ ions has been found to be near C3v in the glass–ceramic nanocomposites. An inverse correlation has been observed between the asymmetric ratio (IED/IMD) of Eu3+ ions and the dielectric constant (ɛr), with an increase in the heat‐treatment time of glass, which is caused by the dipole–dipole interaction.
Reaction Processing of Ultra‐High Temperature W/Ta2C‐Based Cermets
Authors: Teague Melissa C. , Hilmas Gregory E. , Fahrenholtz William G.
Published: June 2009

A reactive processing method was used to produce dense (>99.5% relative density) W/Ta2C/Ta2WO8 cermets from Ta2O5, WC, TaC, and phenolic resin. The powder compacts were reacted under vacuum at 1450°C and then densified at 1850°C. The microstructure of the cermets was examined using scanning electron microscopy and found to contain fine grains on the order of 1–3 μm in diameter. X‐ray diffraction, transmission electron microscopy, and parallel energy electron loss spectroscopy were used to identify the composition and structure of the phases in the composites. The composites were found to contain approximately 47.5 wt% W, 47.3 wt% Ta2C, and 5.2 wt% Ta2WO8. Crack‐free and dense W/Ta2C‐based cermets were prepared by an in situ reactive sintering process without the application of pressure during densification.
Variation in In‐Plane Stress during Densification and Crystallization of Titania Gel Coatings Deposited on Different Substrate Surfaces
Authors: Akase Takatoshi , Ryoke Takuya , Kozuka Hiromitsu
Published: June 2009

Titania gel films were prepared from a coating solution with a starting mole ratio of Ti(OC3H7i)4:H2O:HNO3:C2H5OH=1:1:0.2:30 on Si(100) wafers by spin coating, with and without sol–gel‐derived, fired silica, and titania underlayers. In situ measurement was conducted on the in‐plane stress in the titania gel films during heating up to 500°C at 5°C/min. Basically, for all the gel films, the in‐plane, tensile stress increases once with increasing temperature, and then decreases around the temperature of crystallization. The increase in stress was thought to result from the capillary pressure due to solvent evaporation and from the densification of the coatings. The reduction in stress around the temperature of crystallization was ascribed to the accelerated atomic diffusion in the coatings and to the difference in thermal expansion coefficient between the coatings and the Si wafer. However, when the stress–temperature curves were examined more in detail, differences were found in the variation in stress, depending on the underlayers. Then, the question of how the underlayers could induce the crystallization and relax the strain in the coatings was discussed.
The Crystallization of Ba‐Substituted CsTiSi2O6.5 Pollucite Using CsTiSi2O6.5 Seed Crystals
Authors: Garino Terry J. , Nenoff Tina M. , Park Tae‐Jin , Navrotsky Alexandra
Published: June 2009

Barium (Ba)‐substituted CsTiSi2O6.5 materials of two types, CsxBa1−xTiSi2O(7−x/2) and CsxBa(1−x)/2TiSi2O6.5 were synthesized with the pollucite structure with 1≥x≥0.6. When the Ba‐substituted precursor materials were heat treated to 850°C for 4 h, a mixture of amorphous and unidentifiable phases formed. However, with the addition of 10 wt% of crystalline CsTiSi2O6.5 to the Ba‐containing precursors, nearly single‐phase pollucite was obtained after 20 h at 750°C for x≥0.6. The added crystalline CsTiSi2O6.5 particles act as nuclei that allow the Ba‐containing materials to crystallize into the pollucite phase and to avoid the formation of unwanted phases that would otherwise nucleate and grow. These new materials can be used to study the stability of CsTiSi2O6.5 as a durable ceramic waste form, which could accommodate with time both Cs and its decay product, Ba.
Sintering Behavior of Lead‐Free (K,Na)NbO3‐BasedPiezoelectric Ceramics
Authors: Ahn Cheol‐Woo , Park Chee‐Sung , Choi Chang‐Hak , Nahm Sahn , Yoo Myong‐Jae , Lee Hyeung‐Gyu , Priya Shashank
Published: June 2009

In this manuscript, we investigate the sintering behavior of (K,Na)NbO3 (KNN)‐based ceramics covering unmodified KNN, (K,Na,Li)NbO3 (KNLN), and KNLN–xBaTiO3 (KNLN–BT) systems. Three stages of sintering were identified using detailed temperature and time dependent microscopy. The first stage corresponds to rearrangement of random shape particle to form stack of plate type particles. The second stage is characterized by rapid grain growth promoted by formation of liquid phase. The liquid phase was identified to be Na‐deficient composition. In the final stage of sintering, densification slows and microstructural coarsening becomes the dominant process. The fraction control of liquid phase was an important factor to obtain dense and uniform microstructure by completely filling the voids between the plate‐shaped particle stacks.
Nanosized PbZrO3 Powder from Oxalate Precursor: Microwave‐Aided Synthesis and Thermal Characterization
Authors: Malghe Yuvraj S.
Published: June 2009

Nanosized lead zirconate (PbZrO3) powder was synthesized from its oxalate precursor, namely lead zirconyl oxalate (LZO). LZO heated in a microwave heating system for 1 h yielded the PbZrO3 at 600°C. The same precursor (LZO), when heated in a resistance‐heated furnace at 850°C for 3 h, does not give a pure product. Thermogravimetry, differential thermal analysis, and X‐ray diffraction techniques were used to characterize the precursor and optimize the conditions for microwave processing. The particle size of PbZrO3 powder prepared at 600°C using microwave heating was measured using transmission electron microscopy (TEM). The TEM images show that the particles of PbZrO3 are spherical in shape and that the particle size varies between 20 and 22 nm.
Construction of PbZr0.4Ti0.6O3‐ and Ba0.9Sr0.1TiO3‐Based Optical Microcavities by Chemical Solution Deposition
Authors: Shang Jing L. , Hu Gujin , Zhang Ting , Sun Yan , Wu Jie , Chu Jun H. , Dai Ning
Published: June 2009

Herein we report on a simple, low cost, and feasible route for the construction of PbZr0.4Ti0.6O3 (PZT)‐ or Ba0.9Sr0.1TiO3 (BST)‐based optical microcavities using a single chemical solution containing polymer polyvinylpyrrolidone. The obtained multilayer systems not only exhibit good ferroelectric performance, but also display well‐defined resonant modes with a quality factor of no <66. Compared with PZT microcavities, the optical properties of the BST microcavities appear to be superior.
Hollow Spherical Ti–Al–C Clusters Prepared by Combustion Synthesis
Authors: Liu Guanghua , Li Jiangtao , Yang Yun , Chen Kexin
Published: June 2009

Hollow spherical Ti–Al–C clusters have been prepared by combustion synthesis in air with the assistance of mechanical activation. The clusters have a two‐layered shell structure, where the outer layer consists of Ti–Al–C ternary phases and the inner layer is composed of TiC grains. The reaction procedure and microstructure evolution during the combustion reaction is discussed. It is proposed that the presence of a Ti–Al melt is important for the formation of the hollow spherical clusters.
Deformation Microstructure in (001) Single Crystal Strontium Titanate by Vickers Indentation
Authors: Yang Kai‐Hsun , Ho New‐Jin , Lu Hong‐Yang
Published: June 2009

Recent interests on the plastic deformation of strontium titanate (SrTiO3) are derived from its unusual ductile‐to‐brittle‐to‐ductile transition (DBDT). The transition is divided into three regimes (A, B, and C) corresponding to the temperature range of 113–1053 K (−160° to 780°C), 1053 to ∼1503 K (780° to ∼1230°C), and ∼1503–1873 K (∼1230° to 1600°C), discovered by Sigle and colleagues in the MPI‐Stuttgart. We report the dislocation substructures in (001) single crystal SrTiO3 deformed by Vickers indentation at room temperature, studied by scanning and transmission electron microscopy. Dislocation dipoles of screw and edge character are observed and confirmed by inside–outside contrast using ±g‐vector by weak‐beam dark field imaging. They are formed by edge trapping, jog dragging, and cross slip pinching‐off. Similar to dipole breaking off in deformed sapphire (α‐Al2O3) at 1200°C and γ‐TiAl intermetallic at room temperature, the dipoles pinch off at one end, and emit a string of loops at trail. Two sets of slip systems {110}〈

〉 and {100}〈011〉 are activated under both 100 g and 1 kg load. The suggestion is that plastic deformation has reached the stage II work hardening, which is characterized by multiplication of dislocations through cross slip, interactions between dislocations, and operating of multiple slip systems.
Chemical and Structural Microanalysis of Aluminosilicate Geopolymers Synthesized by Sodium Silicate Activation of Metakaolinite
Authors: Rowles Matthew R. , O'Connor Brian H.
Published: June 2009

An earlier study by the authors on the chemical optimization of compressive strength in aluminosilicate inorganic polymers (geopolymers), produced by sodium silicate activation of metakaolinite (MK), has been extended to provide chemical analysis of the principal microstructural features using scanning electron microscopy/energy dispersive spectrometer (SEM/EDS) measurements. SEM imaging reveals the presence of a two‐phase microstructure; the matrix phase being the fully formed inorganic polymer, while the grain phase is reminiscent of, but chemically dissimilar to, the MK precursor. The current study has provided the following insights into microchemical optimization of compressive strength:

(1) The overall chemical composition of the starting materials does not accurately predict the chemical composition of the geopolymer matrix due to incomplete dissolution of the starting material.

(2) The ideal Na:Al molar ratio of 1.0 required for charge balance in the bonding network has been observed for the matrix.

(3) As the nominal Si:Al molar ratio for the final material increases, the grain Si:Al ratio increases steadily from the MK value, without resulting in the full dissolution of the grain.

These results underline the importance of using SEM/EDS microchemical analysis for designing chemical processing conditions for strength‐optimum geopolymers, rather than relying on imaging or bulk chemistry in isolation, which may provide misleading results.
First‐Principles Study of Elastic Constants and Interlayer Interactions of Complex Hydrated Oxides: Case Study of Tobermorite and Jennite
Authors: Shahsavari Rouzbeh , Buehler Markus J. , Pellenq Roland J.‐M. , Ulm Franz‐Josef
Published: June 2009

It is a common perception that layered materials are soft in the interlayer direction. Herein, we present results of first‐principles calculations of the structure and elastic constants of a class for hydrated oxides, tobermorite, and jennite, which illustrate that this is not the case, if (1) the interlayer distance is such that coulombic interlayer interactions become comparable to the iono‐covalent intralayer interactions and (2) the existence of interlayer ions and water molecules do not shield the coulombic interlayer interactions. In this case, the mechanically softest directions are two inclined regions that form a hinge mechanism. The investigated class of materials and results are relevant to chemically complex hydrated oxides such as layered calcium–silicate–hydrates (C–S–H), the binding phase of all concrete materials, and the principle source of their strength and stiffness. In addition, the first‐principles results may serve as a benchmark for validating empirical force fields required for the analysis of complex calcio–silicate oxides.
Homicides with Mutilation of the Victim’s Body
Authors: Häkkänen‐Nyholm Helinä , Weizmann‐Henelius Ghitta , Salenius Stephan , Lindberg Nina , Repo‐Tiihonen Eila
Published: June 2009

Abstract:  Information on homicide offenders guilty of mutilation is sparse. The current study estimates the rate of mutilation of the victim’s body in Finnish homicides and compares sociodemographic characteristics, crime history, life course development, psychopathy, and psychopathology of these and other homicide offenders. Crime reports and forensic examination reports of all offenders subjected to forensic examination and convicted for a homicide in 1995–2004 (n = 676) were retrospectively analyzed for offense and offender variables and scored with the Psychopathy Check List Revised. Thirteen homicides (2.2%) involved mutilation. Educational and mental health problems in childhood, inpatient mental health contacts, self‐destructiveness, and schizophrenia were significantly more frequent in offenders guilty of mutilation. Mutilation bore no significant association with psychopathy or substance abuse. The higher than usual prevalence of developmental difficulties and mental disorder of this subsample of offenders needs to be recognized.