bluuebunny/crossref_metadata_2025 huggingface dataset:
New Silicone Foam Enhances High-Performance Fabrics
Authors: Hartley Kathleen R.
Published: March 2008

A new room-temperature-curing, silicone-rubber foam can be used as the backing for high-performance composite fabrics. With its excellent adhesion characteristics to fiberglass, foils, silica cloth, silicone-treated fabrics, and wool/nylon blends, the foam is an economical alternative for applications where heat or moisture barrier proper ties are of concern, or where organic foams are unable to meet performance require ments.
Performance Standards for Improving Chemical Protective Suits
Authors: Stull Jeffrey O.
Published: March 2008

This paper describes the basis and requirements of various standards for the manufacture of chemical protective suits currently under development by the Ameri can Society for Testing and Materials (ASTM) and the National Fire Protection Association (NFPA). Standards of both groups are aimed at improving product doc umentation to allow end users to have better information for selecting chemical pro tective suits for their respective applications. NFPA standards will also establish minimum performance requirements judged necessary to provide acceptable levels of protection for end users involved in hazardous chemical response and operations. These standards cover the full range of chemical protective suits ranging from dis posable coveralls to totally-encapsulating protective ensembles. Documentation and performance requirements apply to suit materials and components as well as to the total suit. ASTM and NFPA expect to complete and promulgate each of the standards by late 1989
The Development of a Sound Insulation Package for Car Floor Coverings Using a Combination of Polyurethane Technologies
Authors: Berthevas P.R. , Fanget A. , Gatouillat G.
Published: March 2008

A patented process is used to produce barium sulphate filled polyurethane elastomers using a mechanical frothing technique. The frothed mixture is coated on the underside of the car carpet and cured in an oven. Cup densities ranging from 0,7 to 2 kg/l are used to apply typically 1,0 to 4,0 kg/m2 add-on weight.
Design Evolution of Automatic Dies in Extrusion Coating
Authors: Ferrante Michael A.
Published: March 2008

Slot fed die technology is now more than 40 years old. Today's state of the art die employs automatic bolt adjustment. This paper examines the basis for a good automatic die based on polymer rheology, die design, and practical apphca tions in the extrusion coating field.
New Metal-Coated Fibers and Fabric Lead to Novel, Practical Products
Authors: Orban Ralph
Published: March 2008

Heated garments, space tethers, EMI/RFI shielding, and infrared decoys are some of the current applications being developed for a series of metal- coated fibers and fabrics being produced by Fiber Materials, Inc. at their Space Tech nology Division in Columbus, Ohio Although the processing is proprietary, it does not involve vacuum, high temperature or pressure, and is amenable to both batch and continuous processing. Further, whereas this new process renders fibers and fabrics electrically and thermally conductive, it does not degrade the original properties of the substrate.
Endovascular Treatment of a “Fishy” Ulcer Caused by a Traumatic Arteriovenous Fistula
Authors: Tiwari Alok , Harrington Tim , Vicaretti Mauro
Published: March 2008

Arteriovenous fistula secondary to trauma is an uncommon cause of leg ulcers. In this article, an unusual case of a nonhealing leg ulcer caused by a stingray is described. This case highlights the difficulty in diagnosing and treating nonhealing ulcers secondary to arteriovenous fistula.
The roles of interest groups in US criminal justice policy making
Authors: Stolz Barbaraann
Published: March 2008

The sparse literature on interest groups in US criminal justice policy making has emphasized the importance of professional relative to lay groups. A review of these studies and more recent case studies of US federal criminal justice legislation suggests that lay groups affect criminal justice policy by keeping certain issues off the policy agenda, educating policy makers and the public about emerging issues, and maintaining support for policies. To provide a better understanding of what does or does not become US criminal justice policy, this article proposes a broader definition of the policy making process and a framework for analyzing interest groups in criminal justice.
Policy convergence and crime control in the USA and the UK
Authors: Jones Trevor , Newburn Tim
Published: March 2008

A number of authors have remarked upon growing similarities between the criminal justice systems of western industrialized countries, and in particular, the apparent spread of penal policies associated with the USA to other liberal democracies (Christie, 2000; Nellis, 2000; Garland, 2001; Jones and Newburn, 2002a). Two general approaches to describing and explaining such developments can be identified in the literature, which may be termed `structuralist' and `agency-led' respectively. The former approach links similar developments in crime control policy and discourse in different jurisdictions to deeper cultural and structural changes being experienced in all `late modern' capitalist societies. By contrast, the latter approach focuses more directly upon the arena of political decision making, and the incidence of policy transfer and imitation. This article argues that both these approaches would gain much from a more complex consideration of what `policy' is, and, in particular, where it comes from. More detailed empirical studies of the process of penal policy formation in different countries are a vital precondition to better understanding of how changes in social routines and cultural sensibilities are reflected in key political decisions. This is illustrated by consideration of three high-profile examples of British penal policy developments in recent years, all of which have been associated with similar changes in the USA. These are privatized corrections, `zero tolerance' policing strategies and the registration of sex offenders. We argue that these examples highlight the need for both broad generalizing studies of the structural and cultural preconditions for certain policy developments, and detailed studies of the process of criminal justice policy making.
Globalizing risk?
Authors: O'Malley Pat
Published: March 2008

In the criminal justice arena, the convergence of analyses of `actuarial justice' and the `risk society' thesis, has led many to assume that we will experience a global shift towards risk-based models of justice that are statistical, repressive and incapacitating. It is argued in this article that even where we focus on national jurisdictions sharing risk frameworks of justice and the adoption of neo-liberal politics, there is little evidence that actuarial justice has been successfully exported from the USA. By examining recent developments in Australia, it is shown that local political formations and social conditions have meant that models of justice that are both neo-liberal and risk-based in character diverge so much from US models—in form and function—that we cannot make useful global generalizations about the political character or correctional value of such regimes, or about their simple `transportability' across jurisdictional boundaries.
Continuity and change, convergence and divergence
Authors: Mawby Rob C.
Published: March 2008

Twenty-first century policing operates in a highly mediated environment that places an onus to communicate effectively on police personnel throughout ranks and grades and across roles, but especially on the staff of police force `press offices'. This article uses survey-based research to map out the current policy and practice of police—media relations. Drawing on the research data, I argue that threads of continuity run through police—media relations including police forces' stated intentions to work with media organizations as a means of demonstrating accountability and informing various publics. At the same time a concern with controlling the flow and content of information, and with promoting favourable images of policing is evident. Following consideration of diverging and converging aspects of police—media relations I highlight current trends that suggest future policy and practice will follow a trajectory which utilizes the service of specialist civilian communicators. I conclude that this trajectory will not necessarily support democratically accountable policing and, finally, I outline a possible trajectory which could.
Prevention without politics?
Authors: Sutton Adam , Cherney Adrian
Published: March 2008

The State of Victoria pioneered the late-modern `rediscovery' of community-based crime prevention in Australia when it implemented a Good Neighbourhood Programme in 1988. Loosely based on France's so-called Bonnemaison scheme, Good Neighbourhood was the first of a succession of strategies. The article summarizes the history of crime prevention in Victoria from 1988 to the present, and documents the strengths and weaknesses of each programme implemented. It argues that crime prevention and community safety has been a chameleon movement, capable of accommodating itself to a wide range of political and administrative regimes. Academic criminologists should give greater recognition to the expressive and political dimensions of community safety and crime prevention. Assessments that focus purely on whether initiatives have worked in a technical sense, or that strive simply to locate crime prevention and community safety within broader theories about power and governance, fail to understand key aspects of the Victorian experience.
Economic crime in Sweden
Authors: Lindgren Sven-Åke
Published: March 2008

This article describes and explains the conflicts surrounding economic crime in Sweden between 1975 and 1997. A theoretical approach is employed that views social problems as collective outcomes arising from a clash of interests between different actors. The empirical material comprises public documents and the method employed is a form of qualitative content analysis. The study focuses on the views and positions of the actors concerned in relation to central themes of conflict, such as the phenomenon's definition, extent, victims and harm, causes and countermeasures. Major changes over time have seen the welfare state experiencing competition from the market system as the most prominent category of victimization, and the regulation/control strategy giving way to a strategy of deregulation and self-regulation. The two dominant constellations of actors are an offensive leftist bloc and a more conservative centre-right bloc. These groups represent dominant frames—the social justice/solidarity frame and the deregulation/tax-cut frame—that have served as an ideological infrastructure giving meaning to the economic crime discourse. A clear politicization and polarization have incorporated the economic crime issue into one of 20th-century politics' most well-established conflict patterns. The article concludes with a few comparative impressions based on the limited international literature available in this area.
Legal requirements and nationally circulated materials against school bullying in European countries
Authors: Ananiadou Katerina , Smith Peter K.
Published: March 2008

School bullying has become the focus of attention in many countries in the last 20 years, in part as a result of systematic academic research on the problem, and sometimes extensive media publicity. One of the outcomes of this attention has been an effort on the part of governments and educational authorities in many countries to tackle the problem through various initiatives, including the setting up of anti-bullying legal guidelines that schools must observe. In this article we discuss definitional issues and summarize recent research on school bullying; and then present information on the legal guidelines/requirements against bullying produced by Ministries of Education or equivalent government departments in all EU member states and four associated or candidate states. In addition, we summarize information on anti-bullying materials distributed to schools on a large (national/regional) scale. Our findings show that only a few European countries have specific legal requirements against bullying, although more have requirements on the more general problem of violence at schools. Many countries have produced and distributed anti-bullying materials to schools, although the content and format of these vary considerably. A few European countries still have no anti-bullying actions at a national level. We discuss the policy implications of these findings.
Noninvasive positive pressure ventilation in the acute care setting: where are we?
Authors: Ambrosino N. , Vagheggini G.
Published: March 2008

Noninvasive positive pressure ventilation (NPPV) is a technique used to deliver mechanical ventilation that is increasingly utilised in acute and chronic conditions. The present review examines the evidence supporting the use of NPPV in acute respiratory failure (ARF) due to different conditions.

Strong evidence supports the use of NPPV for ARF to prevent endotracheal intubation (ETI), as well as to facilitate extubation in patients with acute exacerbations of chronic obstructive pulmonary disease and to avoid ETI in acute cardiogenic pulmonary oedema, and in immunocompromised patients. Weaker evidence supports the use of NPPV for patients with ARF due to asthma exacerbations, with post-operative or post-extubation ARF, pneumonia, acute lung injury, acute respiratory distress syndrome, or during bronchoscopy. NPPV should be applied under close clinical and physiological monitoring for signs of treatment failure and, in such cases, ETI should be promptly available. A trained team, careful patient selection and optimal choice of devices can optimise outcome of NPPV.

Noninvasive positive pressure ventilation is increasingly being used in the management of acute respiratory failure but caregivers must respect evidence-supported indications and avoid contraidincations. Additionally, the technique must be applied in the appropriate location by a trained team in order to avoid disappointing results.
Spontaneous potential and redox responses over a forest ring
Authors: Hamilton Stewart M. , Hattori Keiko H.
Published: March 2008

Forest rings are large, circular features in boreal forests that commonly exceed [Formula: see text] in diameter and are visible on aerial photographs. A detailed study of redox conditions and spontaneous potential (SP) was carried out over a forest ring that overlies an [Formula: see text] accumulation. Studies included drilling, monitoring well installation, and downhole SP using both polarizing and nonpolarizing electrodes. Also measured were redox potential of groundwater and soils, concentrations of sulfur species in groundwater, and headspace concentrations of redox-sensitive gases in monitoring wells. The results show positive SP anomalies in the shallow subsurface and near-horizontal, negative-inward redox gradients in the water-saturated overburden at theedges of the ring. SP anomalies are spatially correlated with redox gradients, suggesting that the two are related. The SP anomalies may be produced in response to redox gradients as redox-active ions and polar molecules spontaneously align with the negative poles toward the oxidizing end of the gradient, i.e., toward their more electronegative neighbors. This orientation of dipoles imparts a macroscopic electrical polarity to the redox gradient and results in the observed positive electrical anomaly inside the forest ring. Ongoing oxidation reactions occurring around the periphery of the forest ring maintain strong [Formula: see text] concentration gradients, which result in an outward steady-state diffusive flux of [Formula: see text]. Electromigration of redox-active ions in the redox-induced electrical field may also contribute to maintenance of the redox gradient.
Redatuming through a salt canopy and target-oriented salt-flank imaging
Authors: Lu Rongrong , Willis Mark , Campman Xander , Ajo-Franklin Jonathan , Toksöz M. Nafi
Published: March 2008

We describe a new shortcut strategy for imaging the sediments and salt edge around a salt flank through an overburden salt canopy. We tested its performance and capabilities on 2D synthetic acoustic seismic data from a Gulf of Mexico style model. We first redatumed surface shots, using seismic interferometry, from a walkaway vertical seismic profile survey as if the source and receiver pairs had been located in the borehole at the positions of the receivers. This process creates effective downhole shot gathers by completely moving surface shots through the salt canopy, without any knowledge of overburden velocity structure. After redatuming, we can apply multiple passes of prestack migration from the reference datum of the bore-hole. In our example, first-pass migration, using only a simple vertical velocity gradient model, reveals the outline of the salt edge. A second pass of reverse-time, prestack depth migration using full two-way wave equation was performed with an updated velocity model that consisted of the velocity gradient and salt dome. The second-pass migration brings out dipping sediments abutting the salt flank because these reflectors were illuminated by energy that bounced off the salt flank, forming prismatic reflections. In this target-oriented strategy, the computationally fast redatuming process eliminates the need for the traditional complex process of velocity estimation, model building, and iterative depth migration to remove effects of the salt canopy and surrounding overburden. This might allow this strategy to be used in the field in near real time.
Longitudinal studies of cognition in schizophrenia: Meta-analysis
Authors: Szöke Andrei , Trandafir Anca , Dupont Marie-Estelle , Méary Alexandre , Schürhoff Franck , Leboyer Marion
Published: March 2008

Background

A wide range of cognitive deficits have been demonstrated in schizophrenia, but their longitudinal course remains unclear.

Aims

To bring together all the available information from longitudinal studies of cognitive performance in people with schizophrenia.

Method

We carried out a meta-analysis of 53 studies. Unlike previous reviewers, we included all studies (regardless of the type of medication), analysed each variable separately and compared results with data from controls.

Results

Participants with schizophrenia showed a significant improvement in most cognitive tasks. The available data for controls showed, with one exception (the Stroop test), a similar or greater improvement. Performance in semantic verbal fluency remained stable in both individuals with schizophrenia and controls.

Conclusions

Participants with schizophrenia displayed improvement in most cognitive tasks, but practice was more likely than cognitive remediation to account for most of the improvements observed. Semantic verbal fluency may be the best candidate cognitive endophenotype.
Prevalence and correlates of non-fatal suicidal behaviour among
South Africans
Authors: Joe Sean , Stein Dan J. , Seedat Soraya , Herman Allen , Williams David R.
Published: March 2008

We examined nationally representative data from the 2002–2004 South Africa
Stress and Health Study, a national household probability sample of 4351
persons aged 18 years and older: 9.1% of respondents reported lifetime
suicide ideation, 3.8% a plan and 2.9% an attempt. Among four ethnic groups,
the Coloureda group had the highest lifetime prevalence for
attempts (7.1%). Those at higher risk of suicide attempts had one or more
DSM-IV disorders.
Attributional style and depression
Authors: Ball Harriet A. , McGuffin Peter , Farmer Anne E.
Published: March 2008

Background

Few studies have examined whether attributional style (an individual's explanation of why events happen) is a genetically influenced vulnerability factor for depression.

Aims

To investigate whether attributional style is an enduring vulnerability trait for recurrent depression.

Method

As part of the Cardiff Depression Study, we interviewed 108 people with depression and their siblings, and a control group of 105 healthy individuals and their siblings, using the Schedules for Clinical Assessment in Neuropsychiatry and the Life Events and Difficulties Schedule. Participants also completed the Attributional Style Questionnaire.

Results

Regression analyses showed that attributional style results from mood state and is not a familial risk factor for depression. However, the tendency to internalise negative events was related to having had a prior episode of depression, suggesting a ‘scarring’ effect. Also, non-severe events were associated with one subset of optimistic attributions.

Conclusions

Attributional style mainly measures current mood and does not reflect a familial risk factor for depression.
A ‘dual diagnosis’ community psychiatric nurse service in Lanarkshire: service innovation
Authors: Griffin Shay , Campbell Andy , McCaldin Hazel
Published: March 2008

Aims and Method

We established two ‘dual diagnosis’ community psychiatric nurse posts within community mental health teams in Lanarkshire to improve the service care for individuals with comorbidity. A questionnaire-based evaluation of the service over a 2-year period was conducted.

Results

Comorbidity was under-reported by community mental health teams and under-referred to specialist addiction services. The presence of new specialist nurses enhanced the detection of comorbidity, improved staff perceptions of working with patients that misuse substances, and was associated with a clinical and functional improvement in patients over 2 years.

Clinical Implications

Our findings support the recent trend to provide integrated care for comorbid service users within mainstream mental health services, and suggest a model of service delivery that might be more widely developed to address the concern that such users ‘fall through the gaps’ between services.
Back to basics – getting involved in public education
Authors: Freeman Mona , Stoddart James
Published: March 2008

Being a doctor nowadays is not a role which automatically raises one's status and brings one respect. Our treatment plans and advice are no longer accepted without discussion and/or often compromise. Our patients are now familiar with technical jargon and often come to appointments armed with the ‘latest research’ or up-to-date National Institute of Health and Clinical Excellence (NICE) guidance, which can make such consultations feel more like flashbacks to the Part 2 clinical exam. With an increasingly informed and sometimes critical public regarding all aspects of health and medicine, it is imperative that we, as psychiatrists, are at the forefront of providing information about the illnesses and conditions we treat. Essentially, such information for the public must be easy to understand, accurate and unbiased.
Tungsten, the Surprisingly Positively Acting Heavy Metal Element for Prokaryotes
Authors: Andreesen Jan R. , Makdessi Kathrin
Published: March 2008

The history and changing function of tungsten as the heaviest element in biological systems is given. It starts from an inhibitory element/anion, especially for the iron molybdenum‐cofactor (FeMoCo)–containing enzyme nitrogenase involved in dinitrogen fixation, as well as for the many “metal binding pterin” (MPT)‐, also known as tricyclic pyranopterin– containing classic molybdoenzymes, such as the sulfite oxidase and the xanthine dehydrogenase family of enzymes. They are generally involved in the transformation of a variety of carbon‐, nitrogen‐ and sulfur‐containing compounds. But tungstate can serve as a potential positively acting element for some enzymes of the dimethyl sulfoxide (DMSO) reductase family, especially for CO2‐reducing formate dehydrogenases (FDHs), formylmethanofuran dehydrogenases and acetylene hydratase (catalyzing only an addition of water, but no redox reaction). Tungsten even becomes an essential element for nearly all enzymes of the aldehyde oxidoreductase (AOR) family. Due to the close chemical and physical similarities between molybdate and tungstate, the latter was thought to be only unselectively cotransported or cometabolized with other tetrahedral anions, such as molybdate and also sulfate. However, it has now become clear that it can also be very selectively transported compared to molybdate into some prokaryotic cells by two very selective ABC‐type of transporters that contain a binding protein TupA or WtpA. Both proteins exhibit an extremely high affinity for tungstate (KD < 1 nM) and can even discriminate between tungstate and molybdate. By that process, tungsten finally becomes selectively incorporated into the few enzymes noted above.
Hydrogen and Nickel Metabolism inHelicobacterSpecies
Authors: Benoit Stéphane L. , Maier Robert J.
Published: March 2008

Anaerobic microorganisms (such as clostridia) present in the large intestine of animals generate molecular hydrogen (H2) by fermentation using “H2‐evolving” hydrogenases. The gas can also be detected in other tissues in mice, including the stomach, liver, spleen, or small intestine. It is established that this available H2 can in turn be used as a source of energy by some pathogenic bacteria, including Helicobacter species like H. pylori and H. hepaticus. Both species possess one hydrogenase, which has been studied for H2 oxidation characteristics and for its role in conferring animal colonization. On the basis of available annotated gene sequences, other Helicobacter species also appear to have one well‐conserved respiratory, membrane‐bound, nickel‐iron‐containing [NiFe] hydrogenase. Although H. pylori has been well‐studied, many other (poorly studied) Helicobacter species likely represent a spectrum of emerging pathogens. The important role of hydrogenases in Helicobacter species is discussed, and the hydrogenases, their maturation/accessory factors, their regulation, as well as nickel transport and metabolism among the different species are compared.
Metabolic, Phylogenetic, and Ecological Diversity of the Methanogenic Archaea
Authors: Liu Yuchen , Whitman William B.
Published: March 2008

Although of limited metabolic diversity, methanogenic archaea or methanogens possess great phylogenetic and ecological diversity. Only three types of methanogenic pathways are known: CO2‐reduction, methyl‐group reduction, and the aceticlastic reaction. Cultured methanogens are grouped into five orders based upon their phylogeny and phenotypic properties. In addition, uncultured methanogens that may represent new orders are present in many environments. The ecology of methanogens highlights their complex interactions with other anaerobes and the physical and chemical factors controlling their function.
Life at Extreme Limits
Authors: Mesbah Noha M. , Wiegel Juergen
Published: March 2008

The ability of anaerobic microorganisms to proliferate under extreme conditions is of widespread importance for microbial physiology, remediation, industry, and evolution. The halophilic alkalithermophiles are a novel group of polyextremophiles. Tolerance to alkaline pH, elevated NaCl concentrations, and high temperatures necessitates mechanisms for cytoplasmic pH acidification; permeability control of the cell membrane; and stability of proteins, the cell wall, and other cellular constituents to multiple extreme conditions. Although it is generally assumed that extremophiles growing at more than one extreme combine adaptive mechanisms for each individual extreme, adaptations for individual extremes often counteract each other. However, in alkaline, hypersaline niches heated via intense solar irradiation, culture‐independent analyses have revealed the presence of an extensive diversity of aerobic and anaerobic microorganisms belonging to Bacteria and Archaea that survive and grow under multiple harsh conditions. Thus, polyextremophiles must have developed novel adaptive strategies enabling them to grow and proliferate under multiple extreme conditions. The recent isolation of two novel anaerobic, halophilic alkalithermophiles, Natranaerobius thermophilus and Halonatronum saccharophilum, will provide a platform for detailed biochemical, genomic, and proteomic experiments, allowing a greater understanding of the novel adaptive mechanisms undoubtedly employed by polyextremophiles. In this review, we highlight growth characteristics, ecology, and phylogeny of the anaerobic halophilic alkalithermophiles isolated. We also describe the bioenergetic and physiological problems posed by growth at the multiple extreme conditions of alkaline pH, high NaCl concentration, and elevated temperature under anoxic conditions and highlight recent findings and unresolved problems regarding adaptation to multiple extreme conditions.
The Cellulase/Hemicellulase System of the Anaerobic FungusOrpinomycesPC‐2 and Aspects of Its Applied Use
Authors: Ljungdahl Lars G.
Published: March 2008

Anaerobic fungi, first described in 1975 by Orpin, live in close contact with bacteria and other microorganisms in the rumen and caecum of herbivorous animals, where they digest ingested plant food. Seventeen distinct anaerobic fungi belonging to five different genera have been described. They have been found in at least 50 different herbivorous animals. Anaerobic fungi do not possess mitochondria, but instead have hydrogenosomes, which form hydrogen and carbon dioxide from pyruvate and malate during fermentation of carbohydrates. In addition, they are very oxygen‐ and temperature‐sensitive, and their DNA has an unusually high AT content of from 72 to 87 mol%. My initial reason for studying anaerobic fungi was because they solubilize lignocellulose and produce all enzymes needed to efficiently hydrolyze cellulose and hemicelluloses. Although some of these enzymes are found free in the medium, most of them are associated with cellulosomal and polycellulosomal complexes, in which the enzymes are attached through fungal dockerins to scaffolding proteins; this is similar to what has been found for cellulosomes from anaerobic bacteria. Although cellulosomes from anaerobic fungi share many properties with cellulosomes of anaerobic cellulolytic bacteria and have comparable structures, their structures differ in their amino acid sequences. I discuss some features of the cellulosome of the anaerobic fungus Orpinomyces sp. PC‐2 and some possible uses of its enzymes in industrial settings.
Light-directed Dynamic Structure Formation and Alignment in Photoresponsive Thin Films
Authors: Seki Takahiro , Nagano Shusaku
Published: March 2008

Light provides practical and versatile tools for structure formation and its tuning of soft materials. This article briefly overviews recent developments of photoalignment and phototuning of nanostructured materials focusing onto the 2D material systems. Two topics are involved; i) phototuning and alignment of microphase-separated nanostructures in block copolymers containing a photoisomerizable unit and ii) photoalignment of organic/silica nanohybrids prepared on a polymer film with photocrosslinkable unit.
The First Experimental Demonstration of Benzoporphyrin Formation from Sedimentary Porphyrins
Authors: Nomoto Shinya , Satou Mitsuru , Yoshida Takahiro , Mita Hajime , Kumagai Gen , Nomoto Kouichi , Kigoshi Hideo , Kashiyama Yuichiro
Published: March 2008

Etioporphyrin, one of the most common sedimentary porphyrins, was heated at 300 to 450 °C to investigate the diagenetic formation of benzoporphyrins. Chromic acid oxidation of the resulting products afforded maleimides, as well as phthalimides, indicating the formation of benzopyrrole units in the substrate. Isomer ratios of dimethylphthalimides formed during heating were in accordance with those obtained by chromic acid oxidation of the Cretaceous/Tertiary sediments at Rumoi, Hokkaido, which suggests that alkylporphyrins could be transformed into benzoporphyrins in sediments.
A Facile Method for Preparation of Hollow Polyphenylsilsesquioxane Microspheres
Authors: Jiang Kun , Chi Fangting , Li Bo , Jiang Bo
Published: March 2008

Hollow polyphenylsilsesquioxane microspheres were fabricated under mild conditions from a mixture of water and phenyltriethoxysilane (PTES) with ammonia as catalyst. The pH value and the temperature of the reaction mixture are the crucial factors contributing to the formation of stable and regular polyphenylsilsesquioxane hollow spheres. A possible mechanism for the formation of hollow structure was proposed.
Changes in the four-strand hamstring graft in anterior cruciate ligament reconstruction in the skeletally-immature knee
Authors: Bollen S. , Pease F. , Ehrenraich A. , Church S. , Skinner J. , Williams A.
Published: March 2008

The potential harm to the growth plate following reconstruction of the anterior cruciate ligament in skeletally-immature patients is well documented, but we are not aware of literature on the subject of the fate of the graft itself. We have reviewed five adolescent males who underwent reconstruction of the ligament with four-strand hamstring grafts using MR images taken at a mean of 34.6 months (18 to 58) from the time of operation. The changes in dimension of the graft were measured and compared with those taken at the original operation. No growth arrest was seen on radiological or clinical measurement of leg-length discrepancy, nor was there any soft-tissue contracture. All the patients regained their pre-injury level of activity, including elite-level sport in three. The patients grew by a mean of 17.3 cm (14 to 24). The diameter of the grafts did not change despite large increases in length (mean 42%; 33% to 57%). Most of the gain in length was on the femoral side. Large changes in the length of the grafts were seen.

There is a considerable increase in the size of the graft, so some neogenesis must occur; the graft must grow.
The five-year results of the Birmingham Hip Resurfacing arthroplasty
Authors: Steffen R. T. , Pandit H. P. , Palan J. , Beard D. J. , Gundle R. , McLardy-Smith P. , Murray D. W. , Gill H. S.
Published: March 2008

Few independent studies have reported the outcome of resurfacing arthroplasty of the hip. The aim of this study was to report the five-year clinical outcome and seven-year survival of an independent series.

A total of 610 Birmingham Hip Resurfacing arthroplasties were performed in 532 patients with a mean age of 51.8 years (16.5 to 81.6). They were followed for between two and eight years; 107 patients (120 hips) had been followed up for more than five years. Two patients were lost to follow-up. At a minimum of five years’ follow-up, 79 of 85 hips (93%) had an excellent or good outcome according to the Harris hip score. The mean Oxford hip score was 16.1 points (sd 7.7) and the mean University of California Los Angeles activity score was 6.6 points (sd 1.9). There were no patients with definite radiological evidence of loosening or of narrowing of the femoral neck exceeding 10% of its width. There were 23 revisions (3.8%), giving an overall survival of 95% (95% confidence interval 85.3 to 99.2) at seven years. Fractured neck of femur in 12 hips was the most common indication for revision, followed by aseptic loosening in four. In three hips (three patients) (0.5%), failure was possibly related to metal debris.

Considering that these patients are young and active these results are good, and support the use of resurfacing. Further study is needed to address the early failures, particularly those related to fracture and metal debris.
Segmental vessel ligation in patients undergoing surgery for anterior spinal deformity
Authors: Tsirikos A. I. , Howitt S. P. , McMaster M. J.
Published: March 2008

Segmental vessel ligation during anterior spinal surgery has been associated with paraplegia. However, the incidence and risk factors for this devastating complication are debated.

We reviewed 346 consecutive paediatric and adolescent patients ranging in age from three to 18 years who underwent surgery for anterior spinal deformity through a thoracic or thoracoabdominal approach, during which 2651 segmental vessels were ligated. There were 173 patients with idiopathic scoliosis, 80 with congenital scoliosis or kyphosis, 43 with neuromuscular and 31 with syndromic scoliosis, 12 with a scoliosis associated with intraspinal abnormalities, and seven with a kyphosis.

There was only one neurological complication, which occurred in a patient with a 127° congenital thoracic scoliosis due to a unilateral unsegmented bar with contralateral hemivertebrae at the same level associated with a thoracic diastematomyelia and tethered cord. This patient was operated upon early in the series, when intra-operative spinal cord monitoring was not available.

Intra-operative spinal cord monitoring with the use of somatosensory evoked potentials alone or with motor evoked potentials was performed in 331 patients. This showed no evidence of signal change after ligation of the segmental vessels.

In our experience, unilateral segmental vessel ligation carries no risk of neurological damage to the spinal cord unless performed in patients with complex congenital spinal deformities occurring primarily in the thoracic spine and associated with intraspinal anomalies at the same level, where the vascular supply to the cord may be abnormal.
Idiopathic osteonecrosis of the humeral capitellum
Authors: Nicoletti S. , Salama A. , Stanley D.
Published: March 2008

We present a case of idiopathic osteonecrosis of the humeral capitellum in a 44-year-old female in the absence of any associated risk factors. Arthroscopy was undertaken to remove the loose bodies and debride the capitellum, with a satisfactory outcome.
Hip pain many years after fusion
Authors: Wong K. , Ng T. P. , Chiu K. Y.
Published: March 2008

Arthrodesis of the hip has been employed since the late 19th century. Late complications can arise decades after fusion in patients who were previously asymptomatic. We describe two patients who developed pain in the hip many years after a successful fusion. There was no infection or loosening of the implants. After careful investigation, including oblique radiographs and diagnostic injections of local anaesthetic, the pain was found to be caused by protrusion of the implant. Subsequent removal of the device resulted in complete resolution of the symptoms.
Situation Awareness and the Decision-Making Process in a Dynamic Situation: Avoiding Collisions at Sea
Authors: Chauvin Christine , Clostermann J. P. , Hoc Jean-Michel
Published: March 2008

In this study, the authors aim to determine the impact of situation awareness (SA) in the decision-making process of “young” watch officers of a Merchant Marine training facility. The trainees were shown an ambiguous interaction situation in which they could choose among several actions. The results show that Level 1 SA (perception of the elements in the environment) tends to be of secondary importance in decision making. The major variables of the decision-making process are the interpretation of the rules and anticipation of the other vessel's intentions. Moreover, four different trainee “profiles” emerged. The main difference between them lies in the distance at which they decided to change course, the direction of this maneuver (port or starboard), the way in which they interpreted the other vessel's intentions (is it going to change course?), and whether the trainees referred to the rules. Of the trainees, 55% performed a maneuver that was against regulations, and 34% did so in an unsafe manner. This result provides an incentive to rethink the training course to put more stress on recognizing prototypical situations and choosing which actions to take in situations such as the one presented here.
The Effect of Uncertainty Visualizations on Decision Making in Weather Forecasting
Authors: Nadav-Greenberg Limor , Joslyn Susan L. , Taing Meng U.
Published: March 2008

People's reasoning with uncertainty information is often flawed. Visual representations can help, but little is known about what is the best way to present such information. Two studies investigated the effect of visualizations on the understanding and use of wind speed forecast uncertainty. Participants varied in expertise from novices in weather forecasting (Experiment 1) to professional forecasters (Experiment 2). The authors investigated three visualizations: (a) a chart showing the amount of uncertainty, (b) a chart showing the worst-case scenario, and (c) a box plot of likely wind speeds. Participants were asked to determine the relative uncertainty in the forecast, predict wind speed, and decide whether to post a high-wind warning advisory. The results for novices and professional forecasters were similar. The uncertainty chart enhanced awareness of the degree of uncertainty associated with the forecast, box plots improved reading accuracy, and presenting a visualization of the worst-case scenario introduced bias in the deterministic wind speed forecast. An interactive display (e.g., a combination of an uncertainty chart with a box plot display) may be optimal to convey uncertainty information.
Simultaneously increasing the strength and ductility of the modified casting Al–Cu alloy
Authors: Zhao Wengui , Wang Huiyuan , Wang Jinguo , Li Yong , Jiang Qichuan
Published: March 2008

A modified casting Al–Cu alloy with ultrahigh tensile strength and ductility of about 520 MPa and 13.5% was obtained by PrxOy addition. PrxOy was decomposed to form AlPrO3, which acted as the effective heterogeneous nuclei for the crystallization of the primary α–Al phase. The main reason for the simultaneous increase in the strength and ductility of the modified alloy may be attributed to the effect of a large number of regular, network, and homogeneous nanoscale θ′ phase precipitates and more crystal grain and dendrite boundaries formed by their refinement on restricting and impeding the dislocation actuation and movement.
Hot isostatic pressing synthesis and mechanical properties of Al/Al–Cu–Fe composite materials
Authors: El Kabir T. , Joulain A. , Gauthier V. , Dubois S. , Bonneville J. , Bertheau D.
Published: March 2008

Metal-matrix composites are produced from Al powder and 30 vol% of icosahedral Al–Cu–Fe quasi-crystalline particles using a hot isostatic pressing technique. It is demonstrated that the initial icosahedral phase is transformed into the ω-Al70Cu20Fe10 tetragonal phase during the hot isostatic pressing (HIP) process. The mechanical properties of the composite were evaluated over the temperature range 293 to 773 K by performing compression tests at constant strain rate. The temperature dependence of the yield stress gives evidence of two temperature regimes with a transition temperature at approximately 423 K. Strain-rate sensitivity measurements support the change in rate-controlling deformation mechanisms at this temperature. It is proposed that cross-slip and/or climb mechanism control plastic flow. Finally, it is suggested that the phase transformation of the particle contributes positively to the improvement of the mechanical properties.
Ionic conductivity enhancement in Gd2Zr2O7 pyrochlore by Nd doping
Authors: Mandal B.P. , Deshpande S.K. , Tyagi A.K.
Published: March 2008

The pyrochlore compositions Gd2–yNdyZr2O7 (y = 0.0, 0.1, 0.4, 0.6, 1.0, 1.4, 1.6, and 2.0) were synthesized, and their ionic conductivity was determined (100 Hz–15 MHz, 622–696 K). The direct-current (dc) conductivity (σdc) varies upon Nd substitution at the Gd site, and a peaking effect in σdc was observed around y = 1.0. This indicates that a significant increase in conductivity can be obtained at moderately high temperatures by suitable doping at the Gd site with isovalent rare-earth ions like Nd. The extent of oxygen ion disorder determined from x-ray diffraction was found to decrease with increasing Nd content. The dc conductivity obeys the Arrhenius relation σdcT = σ0 exp(−E/kBT). The activation energy E and the preexponential factor σ0, which is a measure of the concentration of the mobile species, increase while going from the ordered Nd2Zr2O7 to the least ordered Gd2Zr2O7. These two processes presumably lead to the peaking of σdc at an intermediate Nd content. Our results also suggest that the cooperative motion of mobile ions does not contribute much to the increase in activation energy in this compound.
Fabrication of gold nanoparticles in intense optical field by femtosecond laser irradiation of aqueous solution
Authors: Nakamura Takahiro , Mochidzuki Yuzuru , Sato Shunichi
Published: March 2008

Gold particles were fabricated by the high-intensity femtosecond laser irradiation of gold (III) chloride trihydrate (HAuCl4) aqueous solution. The structure and size distribution of the prepared particles were evaluated by transmission electron microscopy. The configuration of the gold particles varied with the concentration of the HAuCl4 aqueous solution. The mean particle size and size distribution were changed by the addition of polyvinylpyrrolidone (PVP), which acted as a dispersant, and monodispersed gold nanoparticles with a diameter of about 3 nm were successfully fabricated. The formation process of the nanoparticles is discussed in terms of the optical decomposition of molecules in the highly intense optical field generated by femtosecond laser irradiation.
Pulsed-laser-induced nc-Si and nc-Si/SiOx core–shell structures on Si substrates
Authors: Ma Y. , Zeng X.T. , Yu T. , Zhu Y. , Shen Z.X.
Published: March 2008

Pulsed-laser-induced Si nanostructures on Si substrates were investigated using third harmonic Nd3+:yttrium aluminum garnet (355nm) laser irradiation under ambient conditions. Nanostructures were found in the laser-irradiated areas as well as in their surrounding areas. The laser-irradiated areas contained Si nanoparticles with an average size of about 50 nm. In the vicinity of the laser-irradiated areas, uniform nc-Si/SiOx core–shell structures were observed. Scanning electron microscopy images indicate that the core–shell structures had an average size of 500 nm while Raman data show that the Si cores were made of a large number of much smaller Si nanocrystals (nc-Si). The photoluminescence (PL) measurement of nc-Si/SiOx core–shells exhibited a broad visible emission centered at 640 nm, which can be assigned as due to defects at the interface between nc-Si and SiOx as well as oxygen-related defects.
High-strain-rate dynamic mechanical behavior of a bulk metallic glass composite
Authors: Martin Morgana , Kecskes Laszlo , Thadhani Naresh N.
Published: March 2008

The high-strain-rate mechanical properties, deformation mechanisms, and fracture characteristics of a bulk metallic glass (BMG)-matrix composite, consisting of an amorphous Zr57Nb5Cu15.4Ni12.6Al10 (LM106) matrix with crystalline tungsten reinforcement particles, were investigated using gas gun anvil-on-rod impact experiments instrumented with velocity interferometry (VISAR) and high-speed digital photography. The time-resolved elastic-plastic wave propagation response obtained through VISAR and the transient deformation states captured with the camera provided information about dynamic strength and deformation modes of the composite. Comparison of experimental measurements with AUTODYN-simulated transient deformation profiles and free surface velocity traces allowed for validation of the pressure-hardening Drucker–Prager model, which was used to describe the deformation response of the composite. The impacted specimens recovered for post-impact microstructural analysis provided further information about the mechanisms of dynamic deformation and fracture characteristics. The overall results from experiments and modeling revealed a strain to failure of ∼45% along the length and ∼7% in area, and the fracture initiation stress was found to decrease with increasing impact velocity because of the negative strain-rate sensitivity of the BMG.