bluuebunny/crossref_metadata_2025 huggingface dataset:
Combined Tibial Tubercle Osteotomy With Medial Opening Wedge High Tibial Osteotomy Minimizes Changes in Patellar Height
Authors: Longino P. David , Birmingham Trevor B. , Schultz William J. , Moyer Rebecca F. , Giffin J. Robert
Published: September 2013

Background:

Medial opening wedge high tibial osteotomy (HTO) for the treatment of varus gonarthrosis can be associated with inadvertent decreases in patellar height.

Hypothesis:

Decreases in patellar height observed after medial opening wedge HTO can be minimized with the addition of a tibial tubercle osteotomy (TTO).

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Twenty-nine patients undergoing medial opening wedge HTO with a concurrent TTO were matched with 29 controls who previously underwent medial opening wedge HTO without a TTO. Both groups had substantial varus malalignment (mean mechanical axis angle, −10° ± 3°) requiring large corrections. Measurements of patellar height and posterior tibial slope were calculated from standing lateral radiographs and compared preoperatively and 6 months postoperatively. Patellar height measures included the Blackburne-Peel index, Caton-Deschamps index, Miura-Kawamura index, Insall-Salvati ratio, and modified Insall-Salvati ratio.

Results:

The changes in the Blackburne-Peel, Caton-Deschamps, and Miura-Kawamura indices were significantly less in the HTO/TTO group versus the HTO group. There were 3 of 29 (10%) new cases that met the radiographic criteria for patella infera in the HTO/TTO group versus 11 of 29 (38%) new cases of patella infera found postoperatively in the HTO group, suggesting an absolute risk reduction of 28% with TTO. The changes in the Blackburne-Peel and Caton-Deschamps indices were correlated to a larger preoperative varus deformity in the coronal plane ( r = 0.52 and r = 0.41, respectively).

Conclusion:

The addition of a TTO when performing a medial opening wedge HTO minimizes the decreases in patellar height associated with the procedure.
The Impact of National Culture on Informal Learning in the Workplace
Authors: Kim Sehoon , McLean Gary N.
Published: September 2013

The purpose of this article was to identify how differing cultural factors affect informal learning in the workplace. We have introduced concepts and reviewed studies on informal learning and national culture based on an extensive literature review on the factors influencing informal learning, particularly based on five Hofstede’s dimensions of national culture. Findings suggest that adult education and workplace learning professionals need to attend to cultural influences and efforts at indigenization when foreign theories or practices are adopted.
Comparative Analysis of Empiric Antimicrobial Treatments for Skin and Soft Tissue Infections in Newly Hospitalized Patients
Authors: Yazdani Cyrus , Hanna Nancy
Published: September 2013

Purpose:

Intravenous vancomycin is the standard empiric treatment for complicated skin and soft tissue infections (SSTIs) due to its coverage against methicillin-resistant Staphylococcus aureus (MRSA). The objective of this study was to compare the hospital length of stay (LOS) between vancomycin-treated patients and patients receiving newer anti-MRSA agents. The study also aimed to identify factors associated with therapy change in patients receiving vancomycin on admission.

Methods:

Electronic medical records were used to conduct this retrospective cohort study. The LOS was compared among 5 groups of adult patients with admission diagnoses for SSTI who were initiated on linezolid, daptomycin, ceftaroline, tigecycline, or vancomycin. Survival analysis was used to identify factors associated with therapy change from vancomycin to another study medication.

Results:

Vancomycin was prescribed in 1046 (92%) admissions. Although none of the between-group differences in LOS reached statistical significance, there was a trend toward shorter LOS in vancomycin-treated patients compared to linezolid-treated patients ( P = .059). Coagulopathy was independently associated with increased likelihood of therapy change from vancomycin (hazard ratio = 4.71; P <.001).

Conclusions:

In the treatment of SSTI, newer agents result in LOS comparable to vancomycin. In patients initiated on vancomycin, therapy change was associated with longer LOS. Coagulopathy was independently associated with increased probability of therapy change.
Dental application of novel finite element analysis software for three-dimensional finite element modeling of a dentulous mandible from its computed tomography images
Authors: Nakamura Keiko , Tajima Kiyoshi , Chen Ker-Kong , Nagamatsu Yuki , Kakigawa Hiroshi , Masumi Shin-ich
Published: September 2013

This study focused on the application of novel finite-element analysis software for constructing a finite-element model from the computed tomography data of a human dentulous mandible. The finite-element model is necessary for evaluating the mechanical response of the alveolar part of the mandible, resulting from occlusal force applied to the teeth during biting. Commercially available patient-specific general computed tomography–based finite-element analysis software was solely applied to the finite-element analysis for the extraction of computed tomography data. The mandibular bone with teeth was extracted from the original images. Both the enamel and the dentin were extracted after image processing, and the periodontal ligament was created from the segmented dentin. The constructed finite-element model was reasonably accurate using a total of 234,644 nodes and 1,268,784 tetrahedral and 40,665 shell elements. The elastic moduli of the heterogeneous mandibular bone were determined from the bone density data of the computed tomography images. The results suggested that the software applied in this study is both useful and powerful for creating a more accurate three-dimensional finite-element model of a dentulous mandible from the computed tomography data without the need for any other software.
Discovery of why acute lymphoblastic leukaemia cells are killed by asparaginase: Adventures of a young post-doctoral student, Bertha K Madras
Authors: Seeman Philip
Published: September 2013

A surprising finding was made by JG Kidd (1909–1991) that guinea pig serum could make tumours disappear in mice. A later finding made by JD Broome (1939–) showed that asparaginase could suppress or kill tumour cells. However, the major mystery was why were only tumour cells but not normal cells affected by the asparaginase? The biology underlying this mechanism was unravelled by a young post-doctoral student, Bertha K Madras (1942–) who hypothesized that cells with low asparagine synthetase are those that die following treatment with asparaginase. To test her theory, Madras developed an assay for asparagine synthetase. The hypothesis was supported by the results that cells with normal asparagine synthetase were protected, while cells with low levels of this enzyme were killed by asparaginase. The findings provide a clinical guide for the use of asparaginase in acute lymphoblastic leukaemia in children and adults.
Determination of School-Related Problems in Children Treated for Cancer
Authors: Yilmaz Medine C. , Sari Hatice Yildirim , Cetingul Nazan , Kantar Mehmet , Erermis Serpil , Aksoylar Serap
Published: September 2013

This descriptive and case–control study was carried out in a pediatric oncology outpatient clinic to determine the school-related physical, social, and psychological problems and problems experienced in academic achievement of children treated for cancer. The sample of the study consisted of 56 Turkish patients with cancer, aged 7–18 years, who were in remission and attending school as well as their parents, a control group of patients who did not have cancer, and their teachers. A Child Information Form, a Child Health Questionnaire Parent’s Form of 50 questions, a Behavior Evaluation Scale for Children, and Young People and a Teacher’s Report Form were used as data collection tools in the study. Of the children, 30.3% experienced various physical difficulties stemming from cancer therapy that affected their school life. The number of late enrollments, the number of children repeating a grade, and the rates of school absenteeism were also found to be higher in the survivors than in the controls.
Witnessing terrorism
Authors: Howie Luke
Published: September 2013

Witnessing is never merely watching or seeing. Witnessing is never a passive practice. Witnessing is active, a performance, an embodied experience. Given the hypermediated nature of the contemporary social world witnessing is particularly common when practised large distances from events. Contemporary terrorists, and their counterparts waging the so-called global ‘war on terror’, depend on near and distant witnesses to spread their violent messages and influence target audiences. Witnessing, however, shows itself to be contradictory and unreliable just like the people who do it, all of whom endure disowned desires and fears. Drawing on the Smithsonian, the September 11 Digital Archive and the story of lower Manhattan graphic novelist Art Spiegelman, I argue that witnessing is what is most at stake in any attempt to understand the meanings and consequences of contemporary terrorism.
The Luhmannian approach to exclusion/inclusion and its relevance to Social Work
Authors: Schirmer Werner , Michailakis Dimitris
Published: September 2013

Although the concept of social exclusion is central to the academic discipline of social work, there is not much theoretical clarity about what it actually means. For instance, exclusion is used as a synonym for poverty, marginalization, detachment, unemployment, or solitude. We argue that the systems-theoretical framework developed by the German social theorist Niklas Luhmann (1927–1997) provides the conceptual tools to understand inclusion and exclusion in a theoretically adequate way that is highly relevant to Social Work. Since there is scarcely any literature on Luhmann's work in the field of social work not written in German, this article aims to provide a systematic introduction to the Luhmannian theory of society with respect to the distinction of inclusion/exclusion and its relation to social work to an English-speaking audience .

Findings

After a presentation of some basic concepts, it will be argued that exclusion is not a problem per se nor is inclusion always and per se unproblematic. The Luhmannian approach suggests that inclusion and exclusion are operations of social systems that treat human beings as relevant addresses for communication. Against that background, systems theory gives a clear and accurate description of what social work can (and cannot) do in terms of inclusion/exclusion.

Applications

The main purpose of social work is exclusion management. Exclusion management involves working on the social addresses of individuals with the aim of improving their attractiveness for other social systems, a (re)orientation towards being includable. It appears in three forms: exclusion prevention, inclusion mediation, and exclusion administration.
Diabetes and nephropathy is not always equal to diabetic nephropathy
Authors: Swaminathan Krishnan , Rani Usha , Sridhar Rohini , Vidi Keerthiga
Published: October 2013

In a busy diabetes clinic, it is always easy for the diabetologist to equate nephropathy and diabetes to “diabetic nephropathy”. Certain clinical clues should arouse suspicion of non-diabetic renal disease as this may have important implications in patient management. We report a case of multiple myeloma in a patient with diabetes presenting as “diabetic nephropathy”.
On the Release of Players to National Teams
Authors: Gürtler Oliver , Lang Markus , Pawlowski Tim
Published: September 2013

The release of players from a club to the national team often leads to a conflict concerning the duration of the players’ stay with the national team. Based on a theoretical bargaining model, we examine whether intervention in this conflict by a governing body is desirable. We show that bargaining between the club and the national federation yields a socially inefficient outcome if financial compensation is either prohibited or limited. If, however, the national federation is allowed to pay unlimited financial compensation to the club, it is not necessary to intervene in the negotiations because the bargaining outcome will be socially optimal.
Giving Nonselective Downsizing a Performance Review
Authors: Bragger Jennifer D. , Kutcher Eugene J. , Menier Amanda , Sessa Valerie I. , Sumner Kenneth
Published: October 2013

The failures of performance management (PM) systems are well known, as is the popularity of downsizing as a corporate strategy. We suggest that the factors integral to the success of PM, such as employee–organization trust, manager–employee communication, goal setting, and reinforcement contingencies, are undermined by organizational downsizing. Broken PM systems increase the likelihood of future downsizing, yet make it difficult to conduct performance-based downsizing. With proper encouragement by HRD professionals and the correct use of employee-centered PM, which may include performance-based downsizing, organizations may break this cycle. Suggested practical implementations include the use of Daniels’s (1985) concept of Performance Management and of Pfeffer and Sutton’s (2006) concept of evidence-based management to (a) implement alternative cost reduction techniques (b) implement contingent PM, that may integrate performance-based downsizing (c) develop HRD specialists and managers to develop and evaluate these integrated systems and (d) reevaluate PM competencies and processes after downsizing has occurred.
Rural School Nurse Perception of Book Studies as an Effective Method for Professional Development
Authors: Gray Lorali
Published: September 2013

School nurses who serve public school districts in rural Northwest Washington face barriers in accessing Continuing Education (CE) for professional development as they often practice in remote, isolated school communities. Acknowledging these barriers, the author discusses the inclusion of book studies within an existing training structure as an innovative method of providing professional development. By utilizing training that is already attended by rural school nurses, CE can be enhanced without incurring additional travel, cost, or training time. The school nurse’s perception of the effectiveness of book studies as a CE method was examined per a descriptive, qualitative program evaluation. Over a period of 5 years, evaluation and feedback data from 12 rural school nurses were compiled from nine individual school nurse book study evaluations and one general satisfaction survey. Findings indicated overall school nurse satisfaction and belief that school nurse book studies are an effective and beneficial method for the delivery of professional development—a method that promotes collaborative learning and collegiality, informs practice, and provides insight into the broader health and social issues impacting today’s students.
Safe use of antithrombotics for stroke prevention in atrial fibrillation: consideration of risk assessment tools to support decision-making
Authors: Wang Yishen , Bajorek Beata
Published: September 2013

Clinical guidelines advocate stroke prevention therapy in atrial fibrillation (AF) patients, specifically anticoagulation. However, the decision to initiate treatment is based on the risk (bleeding) versus benefit (prevention of stroke) of therapy, which is often difficult to assess. This review identifies available risk assessment tools to facilitate the safe and optimal use of antithrombotic therapy for stroke prevention in AF. Using key databases and online clinical resources to search the literature (1992–2012), 19 tools have been identified and published to date: 11 addressing stroke risk, 7 addressing bleeding risk and 1 integrating both risk assessments. The stroke risk assessment tools (e.g. CHADS2, CHA2DS2-VASc) share common risk factors: age, hypertension, previous cerebrovascular attack. The bleeding risk assessment tools (e.g. HEMORR2HAGES, HAS-BLED) share common risk factors: age, previous bleeding, renal and liver impairment. In terms of their development, six of the stroke risk assessment tools have been derived from clinical studies, whilst five are based on refinement of existing tools or expert consensus. Many have been evaluated by prospective application to data from real patient cohorts. Bleeding risk assessment tools have been derived from trials, or generated from patient data and then validated via further studies. One identified tool (i.e. Computerised Antithrombotic Risk Assessment Tool [CARAT]) integrates both stroke and bleeding, and specifically considers other key factors in decision-making regarding antithrombotic therapy, particularly those increasing the risk of medication misadventure with treatment (e.g. function, drug interactions, medication adherence). This highlights that whilst separate tools are available to assess stroke and bleeding risk, they do not estimate the relative risk versus benefit of treatment in an individual patient nor consider key medication safety aspects. More effort is needed to synthesize these separate risk assessments and integrate key medication safety issues, particularly since the introduction of new anticoagulants into practice.
Patients’ attitudes and perceptions of two health-related quality-of-life questionnaires used to collect patient-reported outcome measures in the English National Health Service: A qualitative study of patients undergoing cardiac interventions
Authors: Matata Bashir M , Hinder Susan , Steele Sharon , Gibbons Elizabeth , Jackson Mark
Published: September 2013

Objectives:

To explore patients’ views on the EuroQol-5D and Coronary Revascularisation Outcome Questionnaire, tools currently used for collecting patient-reported outcome measures in the English National Health Service. The key questions were as follows: (1) whether patients consider them sensitive enough to detect change in their health after cardiovascular disease interventions and (2) whether they consider the health-related quality-of-life questions as meaningful.

Methods:

Data were collected on patients’ views using focus groups. We held four focus groups selecting participants on the basis of their baseline and follow-up EuroQol-5D scores. Data were analysed using framework analysis and grounded theory.

Results:

Focus group participants confirmed that they had derived substantial health benefits from their cardiac interventions despite the lack of measurable effects on the EuroQol-5D scores. Participants felt that the EuroQol-5D questionnaire was limited because of the following reasons: Their health fluctuates from day to day. They had difficulty assessing their general health status on the visual analogue scale. They felt that the Coronary Revascularisation Outcome Questionnaire was limited because of the following reasons: They did not understand the clinical terms used. The impact of tiredness on their quality of life was not captured. They were unable to distinguish between the effects of their heart condition and other health issues. Additionally, neither questionnaire considers the adjustments people have made to their domestic arrangements to improve their health-related quality of life.

Conclusion:

This study provides evidence that the two questionnaires do not capture some aspects of health that patients consider important. Furthermore, the presence of co-morbidities masks the symptoms relating to the heart disease and the effect of their cardiac interventions. Future work on patient-reported outcome measures should consider developing new questionnaires that address these major concerns.
Microstructure and properties of ultrasonic assisted copper coated graphite foams
Authors: Song J L , Zhao Y L , He X J , Zhang D S , Tao Z C , Guo Q G , Gao X Q , Shi J L , Liu L , Xia H H , Zhou X T
Published: October 2013

Mesophase pitch based graphite foams were electroplated with copper to obtain the improved mechanical and thermal properties and to extend their applications in heat sinks. A nickel interlayer was electroplated prior to copper to improve the wettability and bonding between copper and the graphite foams. An ultrasonic oscillation device and a rotary cathode were applied to enhance the mass transfer and to ensure the more even coatings throughout the foams from inside. Microstructure and properties of the copper coated foams were studied. Results indicated the copper coatings greatly improved the mechanical and thermal properties of the foams. With the prolonged timescale of plating, the foams possessed enhanced mechanical and thermal properties. After 16 min. of plating, the bending strength of the foams increased from 1·1 to 7·6 MPa, and the thermal conductivity of the foams reached 100·2 from 81·6 W m−1 K−1, while the porosity was reduced only by 4·2.
Using small punch test data to determine creep strain and strength reduction properties for heat affected zones
Authors: Holmström S. , Auerkari P. , Hurst R. , Blagoeva D.
Published: October 2013

The small punch (SP) test is a miniature technique that can provide information on creep performance of local features in welded components. However, the multiaxial stress and deformation history in SP test means that it can be a challenge to interpret the test results in a way that is comparable to uniaxial standard creep testing. This work aimed to compare SP test results from as new and service exposed P91 (9Cr–1Mo–V–Nb) base material (BM) and heat affected zones (HAZ) to uniaxial creep testing results from welded new and service exposed material. Two methods are proposed for predicting the uniaxial strain response for any zone of the weld: one alternative is to apply the SP rupture data and to accommodate the shape of the uniaxial base material creep curve to that of the zone of interest in the SP test. The other alternative is to use the SP deflection data and an appropriate translation function to the uniaxial creep curve. In both cases, the Wilshire creep equations have been used as the rupture model. The approach will also predict the stress reduction factors of welds and its constituent parts (including the subzones of HAZ). It is proposed that the approach is used to provide the local constitutive creep models for component assessment by finite element analysis (FEA).
Effects of reheating temperature and time on microstructure and tensile properties of thixoforged AZ63 magnesium alloy
Authors: Chen T. J. , Huang L. K. , Huang X. F. , Ma Y. , Hao Y.
Published: October 2013

The effects of two main processing parameters such as reheating temperature and reheating time on microstructure and tensile properties of thixoforged AZ63 magnesium alloy have been investigated. The results indicate that these two parameters all have large effects on the microstructure and tensile properties. However, in contrast, the effects of the reheating temperature on liquid fraction and liquid composition of semisolid ingot, and thus the subsequent solidification behaviour and plastic deformation during thixoforging, are larger than those of the reheating time. Therefore, the effects of the former parameter on the microstructure and tensile properties are relatively larger than those of the latter parameter. It is also just this reason that the fracture regime during tensile testing varies as the reheating temperature rises, while the regime always maintains transgranular mode with the variation of the reheating time. Stress concentration that results from the plastic deformation obviously affects the tensile properties, while the primary particle size or grain size only has small effect. The appropriate reheating technique is the heating for 60 min at 595°C when mould temperature is maintained at 350°C. The ultimate tensile strength and elongation of the resulting alloy are up to 310 MPa and 10·7 respectively.
Effects of heat treatment on microstructure and mechanical properties of Mg–2·6Sm–1·3Gd–0·6Zn–0·5Zr alloy
Authors: Yuan M. , Zheng Z. Q.
Published: October 2013

The microstructure and mechanical properties of as cast and different heat treated Mg–2·6Sm–1·3Gd–0·6Zn–0·5Zr (wt-) alloy were investigated. The alloy in the as cast state is mainly composed of α-Mg matrix and (Mg,Zn)3(Sm,Gd)1 eutectic compounds. After solution treatment at 510°C for 4 h, the eutectic compound dissolved into the matrix completely. A good combination of tensile strength and ductility was obtained when the alloy was aged at 200°C for 32 h; the ultimate tensile strength, yield strength and elongation are 282 MPa, 185 MPa and 6·1 respectively. Precipitation strengthening is the largest contributor to strength (∼67) in 200°C peak aged alloy, which is related to plate shaped precipitate phases formed on prismatic planes of the α-Mg matrix.
Variation of microstructure by Ru additions in a single crystal Ni based superalloy
Authors: Tan X. P. , Liu J. L. , Jin T. , Hu Z. Q. , Hong H. U. , Choi B. G. , Kim I. S. , Jo C. Y. , Mangelinck D.
Published: October 2013

The microstructural variation of three single crystal Ni based superalloys with various Ru contents has been investigated. The as cast, solid solution and fully heat treated microstructures were quantitatively analysed. The size of γ′ phase was decreased both in dendrite core and interdendritic regions with Ru additions after a solid solution heat treatment. Appropriate heat treatment schemes of three alloys were determined in terms of quantitative and qualitative microstructural characterisation. It was found that the size and volume fraction of γ′ phase were decreased, and the width of γ matrix channels was reduced in the dendrite core regions of fully heat treated microstructure with the additions of Ru. Moreover, the well known reverse partitioning occurred with increasing Ru content. The γ/ γ′ lattice misfits changed from positive to negative and became more negative with Ru additions. The variation of γ/ γ′ lattice misfit was caused by the changes of partitioning ratios of alloying elements via Ru additions.
Softening behaviour of alumina reinforced copper processed by equal channel angular pressing
Authors: Ranjbar Motlagh S. , Maghsoudi M. H. , Serajzadeh S.
Published: October 2013

In this present work, the softening behaviour of Cu–1·1 wt-Al2O3 alloy containing nanometric alumina particles was investigated. Single pass equal channel angular pressing was first applied on cylindrical specimens, and then, the deformed samples were subjected to annealing treatments in the temperature range of 700–1000°C. Afterwards, finite element analysis, microstructural observations, Vickers hardness and shear punch testing were employed to study strain distribution as well as the recrystallisation behaviour of the examined alloy. It was found that the alloy is softened at 800°C or above, which shows its high thermal stability. Furthermore, a very fine completely recrystallised microstructure was obtained via a continuous mechanism of recrystallisation at 1000°C. The activation energy of recrystallisation was measured to be ∼181 kJ mol−1, which offers a high thermal stability in high temperature applications of this alloy.
Effect of Co substitution for La on hydrogen storage properties and thermal stabilities of amorphous Mg60Ni30La10−xCox (x = 0, 2 and 4) alloys prepared by melt spinning
Authors: Lv P. , Wang Z. , Zhou H. , Deng J. , Yao Q. , Zhang H.
Published: October 2013

A comparison of the hydrogen storage properties and thermal properties of amorphous Mg60Ni30La10−xCox hydrogen storage alloys prepared by melt spinning has been investigated. A, B and C were used to represent each alloy composition when x = 0, 2 and 4 respectively. Their microstructures, the hydrogen storage properties and the thermal stabilities were analysed by X-ray diffraction (XRD), PCTPro2000 and differential scanning calorimetry (DSC) respectively. After hydrogenation of Mg60Ni30La10−xCox (A, B and C) samples at 573 K under 2 MPa hydrogen pressure, XRD pattern results indicate the formation of new phases of MgH2 (A, B, C), Mg2NiH4 (A, B, C), La4H12·19 (A, B, C), Mg2Ni0·9Co0·1H4 (B), Mg2NiH0·26 (C) and Mg2CoH2 (C). It is observed that the experimental data of hydrogen desorption kinetics at 523, 573 and 623 K are well fitted through Avrami–Erofeev equation, and the hydrogen desorption kinetics is in the order of C>B>A. In addition, with increasing Co content, alloy C has the maximum hydrogen absorption capacity of 3·05 wt- and the maximum hydrogen desorption capacity of 2·85 wt-. Based on the results of DSC analysis, dehydrogenation activation energies of these alloys are determined to be 98·31±2·82 kJ mol−1 (A), 96·33±5·61 kJ mol−1 (B) and 78·99±2·98 kJ mol−1 (C), which are in accordance with the results of hydrogen desorption kinetics.
Constitutive model for describing flow behaviour of Fe–18Cr–10Mn–0·39N austenitic stainless steel
Authors: Behjati P. , Araghchi M. , Kermanpur A. , Najafizadeh A.
Published: October 2013

In the present work, a constitutive model is developed to describe the flow behaviour of metastable Fe–18Cr–10Mn–0·39N (wt-) austenitic stainless steel, considering deformed microstructure of the alloy as a composite material (mixture of austenite/ α′-martensite). The results of previous studies are used to validate the model. It is shown that the developed model is more appropriate to predict flow behaviour of the metastable alloy undergoing considerable martensitic transformation during deformation when compared with the modified Ludwik equation suggested in some earlier works.
Comparative study on dissimilar welding of Inconel 718 and Udimet 500 precipitation strengthened nickel based superalloys
Authors: Moosavy H. Naffakh , Aboutalebi M.-R. , Seyedein S. H. , Goodarzi M. , Mapelli C.
Published: October 2013

Microstructural, mechanical and weldability aspects in the similar and dissimilar welds of alloy 718 and alloy 500 nickel based superalloys have been investigated. Alloy 500 weld metal showed high tendency of titanium to the segregation. Coalescence of the microvoids led to propagation of hot solidification microfissures. The alloy 718 weld metal displayed the formation of Nb rich low melting eutectic type morphologies, which can reduce the weldability. The microstructure of dissimilar weld metal with dilution of 65 wt- displayed semideveloped dendritic boundaries. The less segregation and decrease in the low melting eutectics caused less susceptibility of dissimilar weld to solidification cracking. The segregation elimination phenomenon has occurred in the heat affected zone of alloy 500. In the partially melted zone, remelted and resolidified regions have been observed. These locations provided sites for nucleation of liquation cracks. For the alloy 718 heat affected zone, dissolution of γ″-Ni3Nb needle-like precipitations has taken place. It was the chief reason for sharp decline of the microhardness. The heat affected zone of alloy 500 revealed intense liquation cracking, in which the crack is initiated at the partially melted zone. The hot liquation cracking in the heat affected zone of Alloy 718 was observed as a result of γ″-Ni3Nb dissolution.
Structure and properties of solid state diffusion bonding of 17-4PH stainless steel and titanium
Authors: Kundu S. , Bhola S. M. , Mishra B. , Chatterjee S.
Published: October 2013

Solid state diffusion bonded joint between titanium and 17-4 precipitation hardening stainless steel was carried out in the temperature range of 800–1050°C in steps of 50°C for 30 min and also at 950°C for 30–180 min in steps of 30 min under a uniaxial pressure of 3·5 MPa in vacuum. Bonded samples were characterised using light microscopy, field emission scanning electron microscopy and X-ray diffraction technique. Up to 850°C for 30 min, FeTi phase was formed at the diffusion interface; however, α-Fe+ λ, χ, Fe2Ti and FeTi phases and phase mixtures were formed above 850°C for 30 min and at 950°C for all bonding times. Maximum tensile strength of ∼326 MPa, shear strength of ∼254 MPa and impact toughness of ∼24 J were obtained for the diffusion couple processed at 1000°C for 30 min and 30–180 min time interval at 950°C, and maximum tensile strength ∼323 MPa, shear strength ∼243 MPa and impact toughness of ∼22 J were achieved when bonding was processed for 120 min. The residual stress of the bonded joints increases with the increase in bonding temperatures and times.
Austenite grain growth modelling in weld heat affected zone of Nb/Ti microalloyed linepipe steel
Authors: Khalaj G. , Yoozbashizadeh H. , Khodabandeh A. , Tamizifar M.
Published: October 2013

A model to predict the austenite grain size in an Nb/Ti microalloyed steel weld heat affected zone (HAZ) was developed. The present work investigates grain growth behaviour under the influence of pinning carbonitrides. The steel has been subjected to austenitising heat treatments to selected peak temperatures at various heating rates that are typical for thermal cycles in the HAZ. The effect of temperature and heating rate on the grain size is studied. A model is proposed for the dissolution of NbCN precipitates. This model has been coupled to an austenite grain growth model in the presence of pinning particles. This coupling leads to accurate prediction of the austenite grain size along the heating path simulating selected thermal profiles of the HAZ.
Precipitation evolution in duplex stainless steel during isothermal aging at 700°C
Authors: Zhang Z. , Zhang H. , He L. , Han D. , Jiang Y. , Li J.
Published: October 2013

The precipitation evolution in UNS S82441 duplex stainless steel during isothermal aging at 700°C was investigated using scanning electron microscopy and transmission electron microscopy. The image analysis results revealed that nitrides, carbides and σ and χ phases nucleate simultaneously, and the growth of the intermetallic phases lags behind that of nitrides and carbides. Nitrides and carbides precipitated at the ferrite/ferrite interfaces are dissolved, and the χ phase transforms to the σ phase with prolonged aging. In the initial aging stages, the granular σ and χ phases grow and coalesce according to Ostwald ripening. With a treatment time exceeding 4 h, intermetallic grains having a size larger than those of the adjacent ferrite phase grow following a normal grain growth law, while those small in size keep ripening. The grain growth process of the intermetallic phases has been verified theoretically.
Stability and structure prediction of cubic phase in as cast high entropy alloys
Authors: Nong Z.-S. , Zhu J.-C. , Cao Y. , Yang X.-W. , Lai Z.-H. , Liu Y.
Published: October 2013

According to the experimental dataset on the as cast high entropy alloys with cubic structure, the relationship between the stability and physical parameters of cubic structure has been investigated from the view of the atomic size difference, mixing enthalpy, electronegativity difference and valence electron concentration in the present work to reveal the stability and structure formation in as cast high entropy alloys. The results indicated that the mixing enthalpy is the effective parameter that can predict the stability of solid solutions in as cast high entropy alloys. The atomic size difference, electronegativity difference and valence electron concentration also play important roles in the formation of body centred cubic and face centred cubic crystals. Moreover, the back propagation artificial neural network was established using data collected from the calculated solid solution physical parameters and the structure characteristic of as cast high entropy alloys, and the structure of alloys was predicted using this network. The results showed that this model can be used to predict the structure of as cast high entropy alloy accurately, and it can also serve as a guide for the design and application of as cast high entropy alloy.
Characteristics of ultrahigh electrical conductivity for Cu–Sn alloys
Authors: Zhang J. , Cui X. , Wang Y. , Yang Y. , Lin J.
Published: October 2013

The resistivity and mechanical properties of Cu–Sn alloys with different compositions were explored by casting, normalising, cold work and subsequent annealing treatment. Results indicated that the Cu–Sn alloy had the characteristics of ultrahigh electrical conductivity, when the Sn content was ∼0·5 wt-. Note that the resistivity of the as cast and annealed Cu–0·5 wt-Sn alloys is 1·55 and 1·26 μΩ cm respectively.
Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element
Authors: Fischer Anne , Liljander Anne , Kaspar Heike , Muriuki Cecilia , Fuxelius Hans-Henrik , Bongcam-Rudloff Erik , de Villiers Etienne P , Huber Charlotte A , Frey Joachim , Daubenberger Claudia , Bishop Richard , Younan Mario , Jores Joerg
Published: October 2013

Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa.
Obstacles to the prevention of overweight and obesity in the context of child health care in Sweden
Authors: Isma Gabriella E , Bramhagen Ann-Cathrine , Ahlstrom Gerd , Östman Margareta , Dykes Anna-Karin
Published: October 2013

Background

Overweight and obesity in younger children could better be brought in focus through a deeper understanding of how Child Health Care nurses (CHC-nurses) perceive their work with the problems of overweight at the CHC Centers. The aim of this study was to elucidate the CHC-nurses conceptions of their preventive work with childhood overweight and obesity in Child Health Care.

Method

A qualitative study, based on open-ended interviews, involving 18 CHC-nurses strategically selected from 17 CHC Centres in the southern part of Sweden using a phenomenographic approach.

Results

Two categories of description emerged from the data: (i)Internalobstacles to the CHC- nurses’ work with overweight in children and (ii)Externalobstacles to the management of overweight in children. The CHC-nurses conceived their work with overweight in Child Health Care to be complicated and constrained by several obstacles depending on the nurses’ personal priorities, knowledge, responsibility and the absence of resources and cooperation, as well as the lack of uniform guidelines for preventing and managing childhood overweight and further a deficient management organisation.

Conclusion

Nurses’ attention to monitoring overweight in children, and their initiative for prevention, is based on their conceptions of the obstacles that hinder them in their efforts. An increased awareness of the CHC-nurses conceptions of the priorities, their sense of responsibility and prevention practices is warranted. If measures in this direction are not taken there is a growing risk that overweight children will pass through the CHC without any formal recognition of their situation. There is an indication that the present level of the CHC-nurses’ preventive work with childhood overweight has room for improvement in several areas. It is suggested that the specialist education of these health care professionals should be supplemented and that organisation of the management of childhood overweight should be also revised at the primary health care level.
Structural and cognitive deficits in chronic carbon monoxide intoxication: a voxel-based morphometry study
Authors: Chen Hsiu-Ling , Chen Pei-Chin , Lu Cheng-Hsien , Hsu Nai-Wen , Chou Kun-Hsien , Lin Ching-Po , Wu Re-Wen , Li Shau-Hsuan , Cheng Yu-Fan , Lin Wei-Che
Published: October 2013

Background

Patients with carbon monoxide (CO) intoxication may develop ongoing neurological and psychiatric symptoms that ebb and flow, a condition often called delayed encephalopathy (DE). The association between morphologic changes in the brain and neuropsychological deficits in DE is poorly understood.

Methods

Magnetic resonance imaging and neuropsychological tests were conducted on 11 CO patients with DE, 11 patients without DE, and 15 age-, sex-, and education-matched healthy subjects. Differences in gray matter volume (GMV) between the subgroups were assessed and further correlated with diminished cognitive functioning.

Results

As a group, the patients had lower regional GMV compared to controls in the following regions: basal ganglia, left claustrum, right amygdala, left hippocampus, parietal lobes, and left frontal lobe. The reduced GMV in the bilateral basal ganglia, left post-central gyrus, and left hippocampus correlated with decreased perceptual organization and processing speed function. Those CO patients characterized by DE patients had a lower GMV in the left anterior cingulate and right amygdala, as well as lower levels of cognitive function, than the non-DE patients.

Conclusions

Patients with CO intoxication in the chronic stage showed a worse cognitive and morphologic outcome, especially those with DE. This study provides additional evidence of gray matter structural abnormalities in the pathophysiology of DE in chronic CO intoxicated patients.
Non-high altitude methods for rapid screening of susceptibility to acute mountain sickness
Authors: Song Han , Ke Tao , Luo Wen-Jing , Chen Jing-Yuan
Published: October 2013

Background

Acute mountain sickness (AMS) refers to the cerebral abnormalities typically triggered by exposure to hypobaric hypoxia at high altitude. Although AMS is not often life threatening, it can seriously impact health quality and decrease productivity. Thus, detection of potential susceptibility to AMS has become important for people arriving at high-altitude plateaus for the first time, including laborers and military staff. The aim of this review was to examine techniques which efficiently assess the susceptibility to AMS prior to exposure to high altitude.

Methods

By searching online databases, we retrieved studies with associations between AMS and methods to detect the susceptible people who were not exposed to high altitudes. Studies reporting significant correlation coefficients between screening methods and AMS scores were included.

Results

Several screening techniques of AMS susceptibility were found including cold pressor test, heart rate variability, and lung functions. Of these markers, heart rate variability was positively associated with AMS scores, while the rest were negatively associated with AMS scores.

Conclusions

We identified three physiological markers that were significantly associated with the risk of AMS. Although it is well known that simple sea level tests are not really helpful in predicting AMS currently, these markers, to some degree, may be employed as references in predicting susceptibility.
Economic evaluation alongside a single RCT of an integrative psychotherapeutic nursing home programme
Authors: Hakkaart-van Roijen Leona , Bakker Ton JEM , Al Maiwenn , van der Lee Jacqueline , Duivenvoorden Hugo J , Ribbe Miel W , Huijsman Robbert
Published: October 2013

Background

There is an 80% prevalence of two or more psychiatric symptoms in psychogeriatric patients. Multiple psychiatric symptoms (MPS) have many negative effects on quality of life of the patient as well as on caregiver burden and competence. Irrespective of the effectiveness of an intervention programme, it is important to take into account its economic aspects.

Methods

The economic evaluation was performed alongside a single open RCT and conducted between 2001 and 2006. The patients who met the selection criteria were asked to participate in the RCT. After the patient or his caregiver signed a written informed consent form, he was then randomly assigned to either IRR or UC.

The costs and effects of IRR were compared to those of UC. We assessed the cost-utility of IRR as well as the cost-effectiveness of both conditions. Primary outcome variable: severity of MPS (NPI) of patients; secondary outcome variables: general caregiver burden (CB) and caregiver competence (CCL), quality of life (EQ5D) of the patient, and total medical costs per patient (TiC-P). Cost-utility was evaluated on the basis of differences in total medical costs). Cost-effectiveness was evaluated by comparing differences of total medical costs and effects on NPI, CB and CCL (Incremental Cost-Effectiveness Ratio: ICER). CEAC-analyses were performed for QALY and NPI-severity. All significant testing was fixed at p<0.05 (two-tailed). The data were analyzed according to the intention-to-treat (ITT)-principle. A complete cases approach (CC) was used.

Results

IRR turned out to be non-significantly, 10.5% more expensive than UC (€ 36 per day). The number of QALYs was 0.01 higher (non-significant) in IRR, resulting in € 276,290 per QALY. According to the ICER-method, IRR was significantly more cost-effective on NPI-sum-severity of the patient (up to 34%), CB and CCL (up to 50%), with ICERs varying from € 130 to € 540 per additional point of improvement.

Conclusions

No significant differences were found on QALYs. In IRR patients improved significantly more on severity of MPS, and caregivers on general burden and competence, with incremental costs varying from € 130 to € 540 per additional point of improvement. The surplus costs of IRR are considered acceptable, taking into account the high societal costs of suffering from MPS of psychogeriatric patients and the high burden of caregivers. The large discrepancy in economic evaluation between QALYs (based on EQ5D) and ICERs (based on clinically relevant outcomes) demands further research on the validity of EQ5D in psychogeriatric cost-utility studies. (Trial registration nr.: ISRCTN 38916563; December 2004).