bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of the acaricide fenbutatin oxide in water samples by automated headspace‐SPME‐GC/MS
Authors: Devos Christophe , Moens Luc , Sandra Pat
Published: March 2005

The analysis of the acaricide fenbutatin oxide (FBTO) having a molecular weight of 1052.66 g mol–1 in water samples by capillary GC/MS after in‐situ derivatization with sodium tetraethylborate (NaBEt4) and headspace‐SPME enrichment is described. Automated SPME is performed at 80°C for 30 min. Detection is carried out in the ion monitoring mode with deuterated triphenyltin (TPhTd15) as internal standard. Good linearity (R 2 = 0.9993) was obtained in the dynamic range 20 to 1000 ng L–1 with a limit of detection of 16 ng L–1 (LOD at 3 S/N ) and a limit of quantitation of 50 ng L–1 (LOQ at 10 S/N ). Intra‐day RSD% for n = 6 was 8.9 at the LOQ level.
Coupling erosion, vegetation and grazing
Authors: Thornes J. B.
Published: March 2005

This paper argues for the replacement of the carrying capacity approach with an approach that emphasizes the stability conditions of the erosion–vegetation–grazing system. Using digital simulation, it is shown that the vegetation stability (temporal and spatial) is a function not only of rainfall, but also of the non‐linear behaviour of the system through its interactions and through the characteristics of the vegetation in determining response to rainfall. A by‐product is the emergence of erosional hot‐spots (bare patches in the vegetation cover). Some implications for grazing management are briefly discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Combining GIS and stochastic simulation to estimate spatial patterns of variation for lead at the Lousal mine, Portugal
Authors: Reis A. P. , Da Silva E. Ferreira , Sousa A. J. , Matos J. , Patinha C. , Abenta J. , Fonseca E. Cardoso
Published: March 2005

Lousal is one of the many massive sulphide deposits of the Iberian Pyrite Belt. The mine is closed at present, but the heavy metal enriched tailings remain at the surface in the open air. Applying geostatistics to the diagnosis of this potentially contaminated site we aim to assess the quality of the soil. The uncertainty attached to the unknown concentrations of the contaminant was first modelled by a non‐parametric predictor (indicator kriging), and then taken into account in the prediction of the concentrations at unsampled locations by a method of stochastic simulation (p‐field simulation). At each grid node, theNsimulated values resulting from theNequi‐probable simulations were transformed into probabilities of exceeding a regulatory threshold, which allowed assessment of the quality of the soil. The probability maps were then used to identify contaminated areas within the mining field. Copyright © 2005 John Wiley & Sons, Ltd.
Approaches to landcare—a century of soil conservation in Iceland
Authors: Arnalds A.
Published: March 2005

Organized soil conservation in Iceland began in 1907, as a response to severe land degradation and desertification that was threatening the existence of several communities. During the first 75 years, many of the most threatening areas of accelerated soil erosion were fenced and seeded with sand stabilizers. These projects had a high success rate, halting the advancement of sand dunes and other forms of highly accelerated erosion. However, they were limited in scope, and often concentrated on the symptoms of the problems rather than the underlying causes, such as improper grazing management. On a national scale, not enough was being achieved in mitigating the extensive ecosystem degradation. This period of soil conservation in Iceland was characterized by single‐issue, top‐down approaches, a lack of appropriate incentives for soil conservation and weak laws for protection of the rangelands. During the last two decades there has been a gradual shift to more participatory strategies, community involvement, and ecosystem management for multiple benefits. These changes have greatly increased community involvement in projects, stimulated conservation awareness and improved land use. The ties between agricultural policy and soil‐conservation issues are also being strengthened, especially by linking part of governmental subsidies for sheep production to land‐use factors. Copyright © 2005 John Wiley & Sons, Ltd.
Government policies and land degradation in the Middle East
Authors: Nielsen T. T. , Adriansen H. K.
Published: March 2005

The majority of the Middle East is characterized as arid or semiarid and thus susceptible to degradation or even desertification. This paper evaluates long‐term trends in vegetation productivity in the Middle East by means of satellite imagery and discusses the effects of government policies on these trends. Based on yearly estimates of vegetation productivity derived from NDVI, a temporal linear regression model is fitted, pixel by pixel, and the results express the temporal development of vegetation productivity in the region. The results indicate that large‐scale land degradation is not the overall impression in the study area. Approximately 3 per cent of the total area was found to be affected by a marked decline, but only approximately 1 per cent of the total area is affected by significant decreases in vegetation productivity. Three different areas are selected for an in‐depth analysis of the effect of government policies for the trends seen. The three cases—the newly claimed desert lands in Egypt, the marshes in Iraq, and the restructuring process in Israel—are all areas that have undergone significant changes in terms of vegetation productivity over the last twenty years. The results show that these changes are an outcome of government policies rather than local land use practices and these policies can increase or decrease degradation. Copyright © 2005 John Wiley & Sons, Ltd.
Causes and consequences of the Merriespruit and other tailings‐dam failures
Authors: Van Niekerk H. J. , Viljoen M. J.
Published: March 2005

On the night of 22 February 1994, the 31 m high northern wall of the number four tailings dam of the Harmony Gold mine collapsed. The tailings dam is situated 320 m up‐slope of Merriespruit, a suburb of Virginia in the Free State Goldfields of South Africa. More than 2·5 million tonnes of liquefied tailings ripped through the sleeping mining village. Eighty houses were largely swept away and 200 others were severely damaged. Seventeen people were killed.

The failure of this tailings dam shocked everybody who followed the unfolding drama of loss of life and destruction of property in the press. At the inquest following the disaster, the judge called this tailings dam a time bomb that was waiting to explode. For the first time in South African history, processed satellite images were allowed as scientific evidence in court. Together with eyewitness reports, all the evidence pointed overwhelmingly to the cause of the failure as being overtopping. The owner, the operator and six of their employees were subsequently found guilty of negligence and heavy fines were imposed.

The Merriespruit disaster provided the State and the mining industry with the impetus to ensure the safe disposal of tailings. It also made the mining industry and all those involved with the design and operation of tailings dams take stock of their management and tailing disposal methods. Copyright © 2005 John Wiley & Sons, Ltd.
TiN‐Particle reinforced alumina for unlubricated tribological applications mated with metallic counterbodies
Authors: Poser K. , Rohde M. , Schneider J. , Zum Gahr K.‐H.
Published: March 2005

With respect to the application in unlubricated friction systems like dry clutches a commercially available, slightly porous monolithic alumina was modified using laser irradiation by embedding TiN particles. The materials development was carried out by experimental studies and numerical simulation. Temperature and velocity profiles of the molten alumina and the dispersed TiN particles during laser processing were calculated using a finite volume program (PHOENICS). Tribological properties of the modified ceramics were characterized in unlubricated sliding contact with the grey cast iron GJL‐250 and the steel 100Cr6 using a pin‐on‐disc tribometer. Frictional and wear behaviour were analysed at varied sliding speeds. Commercial alumina and silicon carbide ceramics were used as reference materials.

The friction and wear behaviour were determined by mechanical interactions, mainly abrasive processes, material transfer and formation of surface layers from densified wear particles, combined with tribochemical reactions. Sliding pairs with the lasermodified multiphase ceramics showed a greater wear resistance and a greater constancy of the friction coefficient with increasing sliding speed compared to the commercial Al2O3 ceramic.
Influence of surface finish and speed on reciprocating sliding wear of laser modified oxide ceramics in aqueous media
Authors: Peter E. , Zum Gahr K.‐H.
Published: March 2005

Alumina and zirconia toughened alumina ceramic were surface modified by alloying with a powder mixture consisting of 3Y‐ZrO2 and SiO2 using a CO2 laser. Tribological properties of the obtained multiphase microstructures were studied using a ring‐on‐plate laboratory tribometer under reciprocating sliding contact in the presence of distilled water, aqueous hydrochloric solution (HCl) and caustic soda (NaOH). Commercially available monolithic alumina ceramic (F99.7) and ZTA ceramic (SN80) were used as reference materials. The results showed a strong effect of surface finish and average sliding speed as well as the different media used on friction and wear. The occurrence of temporary friction peaks was connected with tribochemical reactions and initial surface cavities. Laser surface treatment resulted in ceramics of improved machinability and lower wear intensity compared with the commercial ceramics.
Failure assessment of alumina in unlubricated unidirectional sliding contact
Authors: Tyulyukovskiy E. , Huber N. , Kraft O.
Published: March 2005

Usual strength and fatigue experiments for ceramic materials determine the failure behaviour at simple stress states with small stress gradients. Recently, ceramics have been also used in applications like gears and pumps because of their outstanding tribological properties compared to metals. The resulting contact loading causes a multi‐axial inhomogeneous stress state with high stress gradients, which have to be considered in the experimental characterisation and failure prediction. A new method for prediction of the contact strength and contact fatigue behaviour of ceramic components under normal, sliding, and cyclic contact loading has been developed [1]. The method is implemented in a fast Contact Design‐Tool (CDT), that works independent from FEM methods and can be used to assess the lifetime and the failure probability of the loaded ceramic. Results obtained from the Contact Design‐Tool for the friction contact of a continuous variable transmission gear [2] show an exponential dependency of the maximum allowed normal pressure in dependency of the friction coefficient of the system. The results indicate, that contact fatigue under spherical loading of alumina is expected only for radii lower than 15 mm.
Interaction between residual stresses and surface defects in alumina ceramics under tribological loading
Authors: Erbacher T. , Beck T. , Vöhringer O.
Published: March 2005

In the presented research work Al2O3 ceramic plates were subjected to frictional and thermal loadings with the main purpose to investigate typical failure mechanisms of ceramic friction components under such loading conditions. This was done by calculating the local temperatures and stresses using the finite element method and subsequently verifying the model developed using experimental results. By conducting residual stress analyses, 4‐point bending tests, ceramographic analyses and fractographic observations on the ceramic components, a detailed interpretation of the crack initiation and propagation was possible.
Investigation of Al2O3‐ and SSiC‐ceramic under lubricated, reciprocating sliding contact and cavitation erosion
Authors: Dulias U. , Zum Gahr K.‐H.
Published: March 2005

Tribological performance of alumina and silicon carbide ceramics as well as of the hardened steel 100Cr6 for reference was studied during reciprocating sliding and cavitation erosion in isooctane as substitute of gasoline and in distilled water. It was the aim to characterize effects of surface finish of the specimens and the liquid media on friction, resistance to sliding wear and cavitation erosion. Sliding wear tests were run on the self‐mated ceramics and ceramic/steel pairs under conditions of boundary lubrication using a laboratory tribometer with cylinder‐on‐plate geometry. Vibratory cavitation erosion tests were conducted according to ASTM G 32‐92.

High initial surface roughness of coarse ground specimens led to a distinct running‐in period during sliding contact with a transition from high to low values of friction coefficient and wear intensity. Incubation time was reduced with increasing surface roughness in the cavitation tests. Depending on the materials investigated, the type of liquid media showed strong effects both during reciprocating sliding and cavitation erosion.
Advanced probabilistic tools for the uncertainty assessment in failure and lifetime prediction of ceramic components
Authors: Roudi S. , Riesch‐Oppermann H. , Kraft O.
Published: March 2005

Reliability analysis of ceramic components under stationary or transient loading is generally performed on the basis of a Finite Element stress analysis from which the failure probability according to the multi‐axial Weakest Link theory is calculated with the help of a suitable post‐processing routine. We use the STAU post‐processing routine and the general purpose Finite Element code ABAQUS. Due to scatter in the material parameters, the resulting failure probability is also prone to statistical uncertainties. We present a method of assessing this scatter using so‐called resampling simulation methods. We obtain confidence intervals for the failure probability. For demonstration, the effect of pooling (i.e. grouping of results from different experiments by suitable scaling procedures) on numerical result and scatter of failure probability is shown for fracture of four‐point‐bending specimens. A more applied example deals with a ceramic component in a clutch test bench under thermo‐mechanical frictional loading. For the assessment of the underlying data base uncertainties, Bayesian credibility intervals based on the posterior distribution are presented and provide advantages compared to a conventional maximum likelihood analysis.
Clutches using engineering ceramics as friction material
Authors: Albers A. , Arslan A. , Mitariu M.
Published: March 2005

The experimental and constructive results illustrate that engineering ceramic materials have a high potential in the field of dry running friction systems. According to first estimations, it is possible to build the vehicle clutch 53 % smaller or to transmit up to 180 % higher torque with the same size by an appropriate selection of the system friction pairing and an adequate ceramic design [1, 2]. The friction coefficient characteristic (decreasing friction coefficient above sliding speed) is unfavourable with regard to comfort (self‐induced grab oscillations [3]) of the vehicle clutch. Furthermore, it is important to select the test procedure of the experimental analyses to be as close to the system as possible in order to obtain exact information concerning the target system.
Ceramic components for high pressure gasoline fuel injection pumps
Authors: Häntsche J. P. , Spicher U.
Published: March 2005

In the present project the use of ceramic materials in piston‐cylinder‐systems of high pressure pumps for gasoline direct injection is investigated. The aim is to generate injection pressures of 300 bar with low friction and wear despite of gasoline's poor lubricity and low viscosity. The high resistance of ceramic materials against wear is used to realise these aims.
Continuously variable transmission (CVT) with ceramic components
Authors: Albers A. , Stuffer A. , Bernhardt J.
Published: March 2005

Continuously Variable Transmissions (CVTs) are a powerful alternative to automatic gearboxes for passenger cars. Some of these CVTs transmit the power via traction forces through highly loaded lubricated contacts. The aim of the presented work is to increase the capability of this system by means of appropriate engineering ceramics. The modifications are investigated on a machine element test bench. The necessary new tools for the design process and the configuration of the test bench are presented. Measurements show that the desired improvements can be achieved by using engineering ceramics but lifetime requirements have not been met yet.
Development of sialon ceramics for lubricated sliding applications
Authors: Holzer S. , Häntsche J.P. , Spicher U. , Badenheim D. , Oberacker R. , Hoffmann M. J.
Published: March 2005

Microstructural design and characterization of mechanical as well as tribological properties of sialon ceramics are the aim of this work. A potential application for these materials are fuel injection pumps for gasoline engines. The currently used metal parts face severe tribological damage with increasing pumping pressures and thus a replacement is needed. Sialon ceramics offer a wide variety of compositional parameters which allow to tailor microstructure and mechanical properties in order to meet the tribological requirements. Since phase boundaries in the sialon system shift depending on the additive elements used, investigations of the phase relations have been performed for two different sintering additives in order to gain informations about reasonable starting compositions. Then, the ratio of the sialon modifications, the amount of grain boundary phase and the grain morphologies have been correlated with the initial composition and the amount of sintering additives. For high hardness values an increase of the fraction of the α‐sialon modification in mixed α/β‐sialon materials is beneficial. The fracture toughness can be raised by promoting growth of elongated grains. It can be done either by achieving higher β‐sialon fractions in mixed α/β‐sialon ceramics or by sintering with an excess of additive in pure α‐sialon materials. Under lubricated sliding with isooctane, sialon ceramics showed a more advantageous behaviour with regard to friction coefficients and wear than commercial silicon nitride and coarse‐grained alumina.
Nutritional inadequacy in adults with muscular dystrophy
Authors: Motlagh Bahareh , MacDonald Jay R. , Tarnopolsky Mark A.
Published: March 2005

Patients with muscular dystrophy may be prone to nutrient deficiency due to mobility limitations or oropharyngeal weakness. Patients with myotonic muscular dystrophy (DM1) may be particularly prone to nutritional deficiencies from associated dysmotility of the entire gastrointestinal tract. We prospectively evaluated nutritional intake, body composition, and muscle strength in adult patients with DM1 (n = 29) and other muscular dystrophies (n = 22) on two occasions separated by ∼6 months. Handgrip was significantly lower and knee extension higher for DM1 compared to other dystrophies, with no between‐group differences in nutritional intakes. Many patients in both groups demonstrated inadequate nutrient intake of protein, energy, vitamins (water and fat soluble), and minerals (calcium and magnesium). Significant correlations were found between measures of strength and certain individual nutrients (e.g., copper and water‐soluble vitamins). These data indicate that a substantial number of adults with muscular dystrophy do not meet current dietary intake recommendations. The potential clinical implications of these findings are discussed. Muscle Nerve, 2005
Discrete stochastic optimization using variants of the stochastic ruler method
Authors: Alrefaei Mahmoud H. , Andradóttir Sigrún
Published: March 2005

We present two random search methods for solving discrete stochastic optimization problems. Both of these methods are variants of the stochastic ruler algorithm. They differ from our earlier modification of the stochastic ruler algorithm in that they use different approaches for estimating the optimal solution. Our new methods are guaranteed to converge almost surely to the set of global optimal solutions under mild conditions. We discuss under what conditions these new methods are expected to converge faster than the modified stochastic ruler algorithm. We also discuss how these methods can be used for solving discrete optimization problems when the values of the objective function are estimated using either transient or steady‐state simulation. Finally, we present numerical results that compare the performance of our new methods with that of the modified stochastic ruler algorithm when applied to solve buffer allocation problems. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.
Single machine scheduling with a restricted rate‐modifying activity
Authors: He Yong , Ji Min , Cheng T. C. E.
Published: March 2005

In this paper we consider the problem of scheduling a set of jobs on a single machine on which a rate‐modifying activity may be performed. The rate‐modifying activity is an activity that changes the production rate of the machine. So the processing time of a job is a variable, which depends on whether it is scheduled before or after the rate‐modifying activity. We assume that the rate‐modifying activity can take place only at certain predetermined time points, which is a constrained case of a similar problem discussed in the literature. The decisions under consideration are whether and when to schedule the rate‐modifying activity, and how to sequence the jobs in order to minimize some objectives. We study the problems of minimizing makespan and total completion time. We first analyze the computational complexity of both problems for most of the possible versions. The analysis shows that the problems are NP‐hard even for some special cases. Furthermore, for the NP‐hard cases of the makespan problem, we present a pseudo‐polynomial time optimal algorithm and a fully polynomial time approximation scheme. For the total completion time problem, we provide a pseudo‐polynomial time optimal algorithm for the case with agreeable modifying rates. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005
A globally convergent numerical algorithm for damaging elasto‐plasticity based on the Multiplier method
Authors: Contrafatto L. , Cuomo M.
Published: March 2005

In the paper it is proposed a new method for the solution of equilibrium problems based on a F.E. displacement formulation, that, at least in principle, is globally convergent as opposed to the classical Lagrangian method that presents only local convergence. The method, which appears to be particularly useful for plasticity models characterized by yield surfaces with regions of sharp curvature or corner points, is based on the Multiplier method. The structure of the procedure is presented and the consequent constrained optimization scheme is implemented for the case of associated plasticity coupled with damage. The main aspect of originality of the proposal is that it is not applied to the ‘return algorithm’, but to entire equilibrium iteration.

At first, the local convergence properties of the constitutive equations are examined at the Gauss point level. It is proved that, also for involved constitutive models (a generalized Ottosen yield surface including isotropic hardening and damage is used in the applications), the convergence of a classical Newton's scheme is always reached with few iterations, ensuring a quadratic rate of convergence in the solution, provided a conversion of the inequality plastic constraint into an equality one is introduced, using an augmented Lagrangian functional for exactly evaluating the slack constraints. However, it is observed that the converged stresses are often attracted far from the initial trial point, towards regions with sharper curvature, and the main reason for the lack of convergence of the procedure is found in a divergence of the solution of the non‐linear equilibrium equations. It is shown that the Multiplier method allows to enlarge the radius of convergence with respect to classical iterations based on the Lagrangian method. The price for the enlargement of the convergence radius is a higher number of iterations, since the Multiplier method presents only a linear rate of convergence. Indeed, the exact fulfilment of the compatibility and admissibility equations is not attained simultaneously, once an equilibrated solution is reached, but it is iterative. In the closure of the paper a convergence analysis of an elastic–plastic problem characterized by a yield criterion resulting from the convex hull of crises surfaces, and as a consequence, presenting regions of non‐differentiability, is presented. It is shown how the ability of the Multiplier method in finding the solution of the structural problem for large loading step with respect to the classical Lagrangian technique compensate its slower convergence rate. Copyright © 2005 John Wiley & Sons, Ltd.
High‐order Higdon‐like boundary conditions for exterior transient wave problems
Authors: van Joolen Vince J. , Neta Beny , Givoli Dan
Published: March 2005

Recently developed non‐reflecting boundary conditions are applied for exterior time‐dependent wave problems in unbounded domains. The linear time‐dependent wave equation, with or without a dispersive term, is considered in an infinite domain. The infinite domain is truncated via an artificial boundary ℬ︁, and a high‐order non‐reflecting boundary condition (NRBC) is imposed on ℬ︁. Then the problem is solved numerically in the finite domain bounded by ℬ︁. The new boundary scheme is based on a reformulation of the sequence of NRBCs proposed by Higdon. We consider here two reformulations: one that involves high‐order derivatives with a special discretization scheme, and another that does not involve any high derivatives beyond second order. The latter formulation is made possible by introducing special auxiliary variables on ℬ︁. In both formulations the new NRBCs can easily be used up to any desired order. They can be incorporated in a finite element or a finite difference scheme; in the present paper the latter is used. In contrast to previous papers using similar formulations, here the method is applied to a fully exterior two‐dimensional problem, with a rectangular boundary. Numerical examples in infinite domains are used to demonstrate the performance and advantages of the new method. In the auxiliary‐variable formulation long‐time corner instability is observed, that requires special treatment of the corners (not addressed in this paper). No such difficulties arise in the high‐derivative formulation. Published in 2005 by John Wiley & Sons, Ltd.
A new positivity‐preserving nonstandard finite difference scheme for the DWE
Authors: Mickens Ronald E. , Jordan P. M.
Published: March 2005

An improved positivity‐preserving nonstandard finite difference scheme for the linear damped wave equation is presented. Unlike an earlier such scheme developed by the authors, the new scheme involves three time levels and is therefore able to include the effects of the equation's relaxation coefficient. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential, 2005
Catheter‐related bacteremia due to Roseomonas species in pediatric hematology/oncology patients
Authors: McLean Thomas W. , Rouster‐Stevens Kelly , Woods Charles R. , Shetty Avinash K.
Published: March 2005

Roseomonas is a newly described genus of pink‐pigmented, gram‐negative bacteria. Human infections caused by Roseomonas species are very rare. We report two cases of central venous catheter‐related bacteremia associated with Roseomonas species (one case with R. gilardii and one with R. fauriae), and review the clinical spectrum of previously reported cases in the literature. Clinicals should be aware that Roseomonas species may cause serious infections in children. Pediatr Blood Cancer 2006, 46:514–516. © 2005 Wiley‐Liss, Inc.
Drug utilization pattern of Chinese herbal medicines in a general hospital in Taiwan
Authors: Chen L. C. , Wang B. R. , Chou Y. C. , Tien J. H.
Published: March 2005

Purpose

Drug utilization studies are important for the optimization of drug therapy and have received a great attention in recent years. Most of the information on drug use patterns has been derived from studies in modern Western medicines; however, studies regarding the drug utilization of traditional Chinese medicine (CM) are few. The present study was the first clinical research to evaluate the drug utilization patterns of Chinese herbal medicines in a general hospital in Taiwan.

Methods

Data were collected prospectively from the patients attending the Traditional Medicine Center of Taipei Veteran General Hospital under CM drug treatments. The study was carried out over a period of 1 year, from January 2002 to December 2002. Core drug use indicators, such as the average number of drugs per prescriptions, the dosing frequency of prescriptions, and the most common prescribed CM herbs and formulae were evaluated. The primary diagnosis and the CM drugs prescribed for were also revealed. All data were analyzed by descriptive statistics.

Results

A total of 10 737 patients, representing 52 255 CM drugs, were screened during the study period. Regarding the prescriptions, the average number of drugs per prescription was 4.87 and 37.21% of prescriptions were composed by five drugs. Most of prescriptions (91.38%) were prescribed for three times a day. The most often prescribed Chinese herb was Hong‐Hwa (5.76%) and the most common Chinese herbal formula was Jia‐Wey‐Shiau‐Yau‐San (3.80%). The most frequent main diagnosis was insomnia (15.58%), followed by menopause (5.22%) and constipation (5.09%).

Conclusion

The survey revealed the drug use pattern of CMs in a general hospital. The majority of CM prescriptions were composed by 3–6 drugs and often prescribed for three times a day. Generally, the rational drug uses of CM drugs were provided with respect to the various diagnoses. Copyright © 2005 John Wiley & Sons, Ltd.
Antipsychotic exposure and type 2 diabetes among patients with schizophrenia: a matched case‐control study of California Medicaid claims
Authors: Lambert Bruce L. , Chou Chia‐Hung , Chang Ken‐Yu , Tafesse Eskinder , Carson William
Published: March 2005

Purpose

To examine the risk of developing type 2 diabetes mellitus among people with schizophrenia exposed to atypical antipsychotics (clozapine, olanzapine, quetiapine, risperidone) compared to those exposed to conventional antipsychotics.

Methods

A matched case‐control design was used to examine California Medicaid beneficiaries. Cases developed diabetes subsequent to being diagnosed with schizophrenia (ICD‐9295), were 18 years or older, and were exposed to at least one antipsychotic medication at some point during the 12 weeks preceding diabetes diagnosis. Diabetes was defined by diagnostic claim (ICD‐9250) or prescription for antidiabetic agents. A total of 3663 cases were matched to 14 523 non‐diabetic controls (people with schizophrenia matched on gender and age ±5 years). All had to be continuously eligible for benefits during the 12‐week period preceding diabetes onset in the case. Conditional logistic regression modeled the risk of exposure, controlling for age, ethnicity, and exposure to selected concomitant medications. Analyses were repeated with 24‐ and 52‐week exposure windows.

Results

Using a 12‐week exposure window, olanzapine (OR = 1.36, 95%CI 1.20–1.53), clozapine (OR = 1.34, 95%CI 1.16–1.55), and combination atypical therapy (OR = 1.58, 95%CI 1.33–1.88), but not risperidone or quetiapine, were associated with increased odds of developing diabetes compared to conventional antipsychotics. Changing to a 24‐week exposure window, the risks were: olanzapine (OR = 1.38, 95%CI 1.22–1.56), clozapine (OR = 1.32, 95%CI 1.14–1.53), or combinations (OR = 1.54, 95%CI 1.29–1.84). With a 52‐week exposure window, the risks were: olanzapine (OR = 1.41, 95%CI 1.24–1.60), clozapine (OR = 1.41, 95%CI 1.21–1.65), combinations (OR = 1.58, 95%CI 1.31–1.90). Risk for olanzapine increased with dose. Hispanic, African American, and unknown ethnicity were significant risks for development of type 2 diabetes as was exposure to selected concomitant medications.

Conclusions

Exposure to olanzapine or clozapine is associated with a 34–41% increase in the developing of type 2 diabetes among California Medicaid recipients with schizophrenia. Prospective, randomized trials are needed to confirm these retrospective, observational findings. Copyright © 2005 John Wiley & Sons, Ltd.
Exploring the risk of diabetes mellitus and dyslipidemia among ambulatory users of atypical antipsychotics: a population‐based comparison of risperidone and olanzapine
Authors: Moisan Jocelyne , Grégoire Jean‐Pierre , Gaudet Michel , Cooper Dan
Published: March 2005

Purpose

To compare the incidence rates of diabetes mellitus and dyslipidemia in ambulatory first‐time users of risperidone and olanzapine.

Methods

The database for the Prescription Drug Insurance Plan in the province of Quebec was used as the data source for a population‐based cohort study. Denominalized data were extracted for all ambulatory patients who first received an atypical antipsychotic between 1 January 1997 and 31 August 1999. Eligible patients were categorized as taking: no antidiabetic medication; no lipid reducing medication; neither type of medication. Those who started to use an outcome drug (an antidiabetic or lipid‐lowering medication) before the end of the follow‐up period (31 August 2000) were considered to have developed the corresponding outcome disease. Incidence rate ratios (IRR) (and 95% confidence intervals) for initiating antihyperglycemic or lipid‐lowering drug treatment, or both were calculated. Outcomes on risperidone were compared to those on olanzapine.

Results

A total of 19 582 eligible patients were included in the analysis. Relative to risperidone, olanzapine was associated with a higher risk of initiating a pharmacologic treatment for diabetes [IRR: 1.33 (1.03–1.74)], dyslipidemia [IRR: 1.49 (1.22–1.83)], or either condition [1.47 (1.23–1.76)].

Conclusions

Olanzapine seems to be associated with a higher risk of developing diabetes and/or dyslipidemia than risperidone. Further prospective studies are needed to rigorously assess the safety of olanzapine. Copyright © 2005 John Wiley & Sons, Ltd.
Overview of recent developments in the flame retardancy of polycarbonates
Authors: Levchik Sergei V , Weil Edward D
Published: March 2005

This paper presents an overview of the recent literature on flame retardancy of polycarbonate (PC) and polycarbonate‐based resins. A brief survey of the major mechanisms of thermal decomposition of PC is also presented because it gives insight in the mechanisms of flame retardant action. Mostly industrial laboratories are involved in the development of new flame retardants for PC and, to a much lesser extent, academic laboratories are doing research on the mechanistic aspects of flame retardancy. The number of patents published annually on the flame retardancy of PC and its blends significantly exceeds the number of patents on flame retardancy of any other polymer. Because PC is a naturally high charring polymer, the condensed phase active flame retardants, in particular phosphorus‐based ones, are widely used in PC‐based blends. Plain PC can pass stringent flame retardant tests with very low additions of some sulfur‐ or silicone‐based flame retardants. Copyright © 2005 Society of Chemical Industry
Free radical activity in gamma‐irradiated polyethylene film, drawn tape and ultra‐high‐modulus fibres determined by grafting performance
Authors: Busfield W Ken , Watson Gregory S
Published: March 2005

Grafting rates of gaseous butadiene to a range of morphological forms of gamma‐irradiated polyethylene, including ultra‐high‐modulus fibres (UHMPE), have been measured in order to determine the availability of active free radicals over time at various temperatures. Blank experiments on unirradiated samples showed that monomer diffusion is not rate‐controlling with film and natural draw ratio tapes, but is likely to be a major factor in the control of grafting rates in UHMPE fibres. Grafting rates from monomer loss/time experiments with irradiated samples indicate that grafting is always in competition with free radical self‐annihilation, the extent being influenced by temperature, dose and morphology, including prior sample annealing. At lower temperatures, graft‐active radicals are produced over long periods of time, eg close to linear grafting rates were monitored over 20 hours for PE tape at 0 °C (50 kGy) and for gel‐spun UHMPE at 40 °C (100 kGy). At higher temperatures, grafting rates steadily decrease with time. Grafting rates are almost independent of irradiation dose in the early stages, however, the dose has an increasing positive influence as the reaction proceeds. At any given temperature and irradiation dose, the rates decrease in the series undrawn film; natural draw ratio tape; high draw ratio gel‐spun fibre; high draw ratio melt‐spun fibre. An analogy is drawn between these results and the optimum conditions required for improving the creep properties of PE tape and UHMPE fibres by acetylene‐sensitized irradiation crosslinking. Copyright © 2005 Society of Chemical Industry
Chemical sensing materials based on electrically‐conductive immiscible polymer blends
Authors: Segal Ester , Tchoudakov Roza , Mironi‐Harpaz Iris , Narkis Moshe , Siegmann Arnon
Published: March 2005

Two families of electrically‐conductive immiscible polymer blends were studied as liquid sensing materials for an homologous series of alcohols. The systems studied include: multiphase matrices [containing carbon black (CB)] consisting of either polypropylene or high‐impact polystyrene as the major phase and thermoplastic polyurethane as the minor dispersed phase; and polyaniline (PANI) dispersed within a polystyrene matrix. Extruded filaments, produced by a capillary rheometer at various shear‐rate levels were used in the sensing experiments. The electrical resistance of these filaments was selectively sensitive to the various alcohols. Moreover, the responses displayed by these filaments are reproducible and reversible. The sensing behaviour of these blends is determined by the nature of the blend components, the blend composition and the processing conditions. An attempt is made to identify the dominant mechanisms controlling the sensing process in CB‐containing immiscible polymer blends and PANI‐containing blends. In addition, the sensing performances of these blends are compared in the light of their sensing mechanisms. Copyright © 2005 Society of Chemical Industry
Catalytic effect of dimethyl sulfoxide in the Cu(0)/tris(2‐dimethylaminoethyl)amine‐catalyzed living radical polymerization of methyl methacrylate at 0–90 °C initiated with CH3CHClI as a model compound for α,ω‐di(iodo)poly(vinyl chloride) chain ends
Authors: Percec Virgil , Guliashvili Tamaz , Popov Anatoliy V. , Ramirez‐Castillo Ernesto
Published: March 2005

A variety of conditions, including catalysts [CuCl, CuI, Cu2O, and Cu(0)], ligands [2,2′‐bipyridine (bpy), tris(2‐dimethylaminoethyl)amine (Me6‐TREN), polyethyleneimine, and hexamethyl triethylenetetramine], initiators [CH3CHClI, CH2I2, CHI3, and F(CF2)8I], solvents [diphenyl ether, toluene, tetrahydrofuran, dimethyl sulfoxide (DMSO), dimethylformamide, ethylene carbonate, dimethylacetamide, and cyclohexanone], and temperatures [90, 25, and 0 °C] were studied to assess previous methods for poly(methyl methacrylate)‐b‐poly(vinyl chloride)‐b‐poly(methyl methacrylate) (PMMA‐b‐PVC‐b‐PMMA) synthesis by the living radical block copolymerization of methyl methacrylate (MMA) initiated with α,ω‐di(iodo)poly(vinyl chloride). CH3CHClI was used as a model for α,ω‐di(iodo)poly(vinyl chloride) employed as a macroinitiator in the living radical block copolymerization of MMA. Two groups of methods evolved. The first involved CuCl/bpy or Me6‐TREN at 90 °C, whereas the second involved Cu(0)/Me6‐TREN in DMSO at 25 or 0 °C. Related ligands were used in both methods. The highest initiator efficiency and rate of polymerization were obtained with Cu(0)/Me6‐TREN in DMSO at 25 °C. This demonstrated that the ultrafast block copolymerization reported previously is the most efficient with respect to the rate of polymerization and precision of the PMMA‐b‐PVC‐b‐PMMA architecture. Moreover, Cu(0)/Me6‐TREN‐catalyzed polymerization exhibits an external first order of reaction in DMSO, and so this solvent has a catalytic effect in this living radical polymerization (LRP). This polymerization can be performed between 90 and 0 °C and provides access to controlled poly(methyl methacrylate) tacticity by LRP and block copolymerization. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1935–1947, 2005
Growth of polystyrene films via gas‐phase polymerization with [Pd(CH3CN)4][BF4]2 thin film catalyst
Authors: Wain Kimberly S. , Sen Ayusman , Kim Seong Han
Published: March 2005

The heterogeneous catalytic polymerization of styrene vapor with a tetrakis(acetonitrile)palladium(II) tetrafluoroborate, [Pd(CH3CN)4][BF4]2, thin film has been demonstrated. The catalyst is deposited by nebulization of dilute solutions onto a quartz crystal microbalance (QCM) and then exposed to styrene vapor in controlled environments. The use of QCM allows in situ monitoring of catalyst deposition and polymer growth kinetics. The polymerization process appears to involve the entire catalyst film rather than polymerization only at the catalyst film surface. The styrene vapor polymerization occurs rapidly after a short induction time needed for monomer dissolution and catalyst activation. The narrow molecular weight distribution of the produced polymer suggests that the deposited film acts as a single site catalyst. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1930–1934, 2005
The psychological impact of mammographic screening. A systematic review
Authors: Brett J. , Bankhead C. , Henderson B. , Watson E. , Austoker J.
Published: March 2005

Concerns have been raised regarding the possible negative psychological impact of the cancer screening programmes offered in the UK. This review aims to assess the extent of and factors associated with the adverse psychological consequences of mammographic screening. Fifty‐four papers from 13 countries were identified, a majority of which were published after 1990, coinciding more or less with the onset of routine mammographic screening. The results report that mammographic screening does not appear to create anxiety in women who are given a clear result after a mammogram and are subsequently placed on routine recall. However, women who have further investigations following their routine mammogram experience significant anxiety in the short term, and possibly in the long term. The nature and extent of the further investigation that women are exposed to during mammographic screening determines the intensity of the psychological impact. Factors associated with the adverse psychological impact of mammographic screening included: social demographic factors of younger age, lower education, living in urban areas, manual occupation, and one or no children; cancer screening factors of dissatisfaction with information and communication during screening process, waiting time between recall letter and recall appointment, pain experienced during the mammographic screening procedures, and previous false positive result; and cancer worry factors including fear of cancer and greater perceived risk of breast cancer. Difficulties in measuring the psychological impact of screening are discussed, and methods of alleviating the negative psychological outcomes are suggested. Copyright © 2005 John Wiley & Sons, Ltd.
Magnetically soft and high‐saturation‐magnetization FeCo films fabricated by co‐sputtering
Authors: Fu Yu , Cheng Xiaofeng , Yang Zheng
Published: March 2005

Magnetically soft FeCo films with high saturation magnetization were successfully obtained by co‐sputtering Fe65Co35films onto a very thin Co93Fe7seed layer. The coercivity of single FeCo films on the substrate was markedly reduced by increasing the deposition temperature and appropriately selecting the composition. The effect of composition and thickness of a high‐Co‐concentration Co100–yFey(0 ≤y≤ 11) seed layer on the magnetic properties and structure of Co100–yFey(0–10 nm)/Fe65Co35(100 nm) films was studied. It was observed that the texture of Fe65Co35films changed from (110) to (200) on using a Co100–yFeyseed layer. The appearance of (200) texture and film growth with less lattice strain improved the soft magnetic properties of FeCo films. A double‐layer Co93Fe7(1 nm)/Fe65Co35(100 nm) film was obtained with saturation magnetizationμ0Ms= 2.4 T, easy‐axis coercivityHce= 1 kA/m, hard‐axis coercivityHch= 0.2 kA/m and anisotropy fieldHK= 6.4 kA/m. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Shot noise as a probe of electron transport via localised states in sub‐micrometer barriers
Authors: Savchenko A. K. , Safonov S. S. , Roshko S. H. , Bagrets D. A. , Jouravlev O. N. , Nazarov Y. V. , Linfield E. H. , Ritchie D. A.
Published: March 2005

We show that shot noise is a useful tool in studies of electron transport in hopping and resonant tunnelling between localised states. In resonant tunnelling through a single impurity we observe an enhancement of shot noise caused by Coulomb interaction between two resonant channels. In hopping along chains of localised states, shot noise is shown to be sensitive to the distribution of the barriers between the states and the Coulomb interaction between hopping electrons. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin polarization and annihilation for radicals and diradicals
Authors: Davidson Ernest R. , Clark Aurora E.
Published: March 2005

The extent of spin polarization in unrestricted Hartree–Fock and density functional B3LYP calculations has been determined for a few monoradicals as well as the corresponding diradicals containing these monoradicals as functional groups. Simple relations are found that explain the very high value for the average spin after projecting out the triplet component from a broken‐spin calculation on the singlet state. The implications of these results for estimating the energy of the low‐spin diradical by spin projection or by the Heisenberg Hamiltonian are discussed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
On the original proof by reductio ad absurdum of the Hohenberg–Kohn theorem for many‐electron Coulomb systems
Authors: Kryachko Eugene S.
Published: March 2005

It is shown that, for isolated many‐electron Coulomb systems with Coulombic external potentials, the usual reductio ad absurdum proof of the Hohenberg–Kohn theorem is unsatisfactory since the to‐be‐refuted assumption made about the one‐electron densities and the assumption about the external potentials are not compatible with the Kato cusp condition. The theorem is, however, provable by more sophisticated means, and it is shown here that the Kato cusp condition actually leads to a satisfactory proof. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005