bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Model, Buckling Analysis and Ultimate Load Capacity of the Single-Double-Layer Reticulated Dome
Authors: Qing-Hua Han , Xi-Liang Liu
Published: April 2004

The advantages of two different structural types can be developed by combining the single layer spherical dome and the double layer square pyramid space grids. According to the different types of joints, three practicable numerical models are put forward, which are the pin-jointed model, rigid-jointed model and the rigid-pin-jointed model. The eigen-values and the eigen-vectors are analyzed using the Block Lanczos method with three different models. The equilibrium path is traced using the Cylindrical Arc Length Method. Based on the analysis of several factors including the single-layer-width-to-span ratio, the height-to-span ratio and the pipe types, the stability behaviors are summarized and the fitting formulae for critical load and ultimate load are obtained. The comparison between the simplified formula and the numerical analysis of an engineering project is given as well.
A New Catenary Cable Element
Authors: Chunjiang Wang , Renpeng Wang , Shilin Dong , Ruojun Qian
Published: April 2004

In this paper, a new explicit analytical solution of a single cable with two fixed points was presented by considering the equilibrium and geometric conditions of the cable mini-element. Combining the analytic solution and virtual work principle, the authors proposed a new two-node catenary cable element. By comparing the stiffness matrix of the new cable element and the two-node straight-line cable element, a simplified matrix form was presented and a nonlinear analysis procedure considering the influence of cable initial sag and force was given. This cable element has the advantage of high computing precision and simple expression compared with multi-node cable element and other cable elements. Two numerical examples illustrated the accuracy and reliability of the nonlinear element presented in this paper.
The Cocoon Method: A Physical Modelling Tool for Designing Tensegrity Systems
Authors: Sakantamis Konstantinos , Larsen Olga Popovic
Published: April 2004

Although the invention of Tensegrities dates back to the beginning of the twentieth century, applications of this structural form are scarce, due to the lack of analytical and practical tools required for the design and prediction of their performance. The Cocoon Method, presented in this paper, is a practical physical-modelling tool for designing tensegrity systems, which can easily be used by designers having a non-mathematical background in the creative formfinding of tensegrities. This tool is introduced through its application in three case studies and reports on a workshop that asked undergraduate architecture students at the University of Sheffield, UK, to test it and answer a brief questionnaire.
Guanxi Practices and Trust in Management: A Procedural Justice Perspective
Authors: Chen Chao C. , Chen Ya-Ru , Xin Katherine
Published: April 2004

Taking a procedural justice perspective, we examined the effect of guanxi practices in human resources management (i.e., making human resources management decisions on the basis of personal relationships) on employees' trust in management in Chinese organizations. Two studies were conducted. In the first, a survey study, we found a negative effect of guanxi practices on trust in management, which was mediated by perceived procedural justice. In the second, an experimental study, we found that the negative effect of guanxi practices varied as a function of guanxi bases: favoring a nephew or a hometown fellow lowered trust, but favoring a college schoolmate or a close friend did not. Theoretical and practical implications are discussed.
Rewards-Allocation Preferences of Chinese Employees in the New Millennium: The Effects of Ownership Reform, Collectivism, and Goal Priority
Authors: He Wei , Chen Chao C. , Zhang Lihua
Published: April 2004

The ownership restructuring of Chinese state-owned enterprises, launched in 1992, has been one of the most radical and far-reaching market-oriented reforms in the Chinese economy. We studied the effects of ownership reform and individuals' collectivist values on rewards-allocation preferences of employees in Chinese state-owned enterprises, and how these relationships were mediated by employees' productivity goal orientation. We predicted the effects of ownership reform and collectivism on rewards-allocation preferences based on the model of allocation goal priority and the conceptual distinctions of vertical and horizontal collectivism. With data from four pairs of public state-owned enterprises (i.e., listed on the stock market) versus pure state-owned enterprises, we found the following results. First, employees of enterprises that had experienced a greater degree of ownership reform expressed stronger preferences for differential allocation rules (e.g., job position and performance) but weaker preferences for equalitarian allocation rules (e.g., group and individual equality). Second, vertical collectivism was positively related to preferences for differential allocation rules, but horizontal collectivism was positively related to preferences for equalitarian allocation rules. Third, the effects of both ownership reform and vertical collectivism on differential allocation preferences were mediated by productivity goal orientation. Research and practical implications for ownership reform and vertical-horizontal collectivism are discussed.
Rhabdomyolysis in Association with Simvastatin and Amiodarone
Authors: Roten Laurent , Schoenenberger Ronald A , Krähenbühl Stephan , Schlienger Raymond G
Published: April 2004

OBJECTIVE:

To report a case of severe myopathy associated with concomitant simvastatin and amiodarone therapy.

CASE SUMMARY:

A 63-year-old white man with underlying insulin-dependent diabetes, recent coronary artery bypass surgery, and postoperative hemiplegia was treated with aspirin, metoprolol, furosemide, nitroglycerin, and simvastatin. Due to recurrent atrial fibrillation, oral anticoagulation with phenprocoumon and antiarrhythmic treatment with amiodarone were initiated. Four weeks after starting simvastatin 40 mg/day and 2 weeks after initiating amiodarone 1 g/day for 10 days, then 200 mg/day, he developed diffuse muscle pain with generalized muscular weakness. Laboratory investigations revealed a significant increase of creatine kinase (CK) peaking at 40 392 U/L. Due to a suspected drug interaction of simvastatin with amiodarone, both drugs were stopped. CK normalized over the following 8 days, and the patient made an uneventful recovery. An objective causality assessment revealed that the myopathy was probably related to simvastatin.

DISCUSSION:

Myopathy is a rare but potentially severe adverse reaction associated with statins. Besides high statin doses, concomitant use of fibrates, defined comorbidities, and concurrent use of inhibitors of cytochrome P450 are important additional risk factors. This is especially relevant if statins predominantly metabolized by CYP3A4 are combined with inhibitors of this isoenzyme. Amiodarone is a potent inhibitor of several different CYP isoenzymes, including CYP3A4.

CONCLUSIONS:

Avoiding the concomitant use of drugs with the potential to inhibit CYP-dependent metabolism (eg, amiodarone) or elimination of statins may decrease the risk of statin-associated myopathy. Alternatively, if drug therapy with a potent CYP inhibitor is inevitable, choosing a statin without relevant CYP metabolism (eg, pravastatin) should be considered.
Disputed memories of twins: how ordinary are they?
Authors: Küntay Ayli̇n C. , Gülgöz Sami̇ , Tekcan Ali̇ İ.
Published: April 2004

Two studies reported that twins may dispute ownership of autobiographical experiences. One observation made in both studies was that the events that were disputed by the twins were rather ordinary events. In the present study, we tested the idea that the disputed memories are such ordinary and mundane events. A brief narrative description of disputed and nondisputed events that were provided by participants in the Ikier, Tekcan, Gülgöz, and Küntay (2003) study was given to an independent sample of participants who were asked to rate (a) the ordinariness of the event, given the age and sex of the protagonist of the event and (b) the likelihood that the event would have happened to them. Results showed that disputed memories were rated as more mundane than nondisputed personal memories. Moreover, a substantial portion of the disputed memories from the Ikier et al. study were for events that our subjects reported to have also experienced. These findings are discussed in the context of cognitive processes contributing to formation of false memories. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of verbalization on lineup face recognition in an interpolated inspection paradigm
Authors: Lyle Keith B. , Johnson Marcia K.
Published: April 2004

We examined the effects of describing a target face on face memory in a procedure in which subjects either did or did not inspect a single distractor face to determine if it matched the target face before attempting lineup identification of both the target and the distractor. Verbalization did not affect accuracy of identification of the target face; however, it increased accuracy during inspection of the distractor face and improved subsequent lineup identification of the distractor face. The absence of description‐related impairment of memory for the target face (i.e. the failure to find verbal overshadowing), and the fact that verbalization has the potential positive effect of reducing false alarms to the distractor, points to the complex relation between verbalization and memory for faces. Copyright © 2004 John Wiley & Sons, Ltd.
Hydrogenation of Citral using Monometallic Pt and Bimetallic Pt‐Ru Catalysts on a Mesoporous Support in Supercritical Carbon Dioxide Medium
Authors: Chatterjee M. , Zhao F. Y. , Ikushima Y.
Published: April 2004

Supercritical carbon dioxide was shown to be a suitable reaction medium for the highly efficient hydrogenation of citral using monometallic Pt and bimetallic Pt‐Ru supported on a mesoporous material, MCM‐48, as catalyst. A remarkable change in the product distribution was observed after the addition of Ru to the monometallic Pt catalyst in supercritical carbon dioxide. The monometallic Pt catalyst was found to be highly selective to the unsaturated alcohol (geraniol+nerol) at a temperature of 323 K within 2 h whereas the bimetallic catalyst becomes selective to the partially saturated aldehyde (citronellal) under the same reaction conditions. Phase behavior plays an important role in the product distribution. Highest conversion and high selectivity to citronellal were achieved in the homogeneous phase for the Pt‐Ru catalyst while on the other hand the unsaturated alcohol (geraniol+nerol) was produced in the heterogeneous phase for the monometallic Pt catalyst. An XPS study offers strong evidence of the electronic modification of Pt after the addition of Ru in the bimetallic catalyst. The change in product distribution on the Pt‐Ru bimetallic catalyst may be explained by the appreciable interaction between the medium and the metal particles promoted by the presence of metallic Ru.
Synthesis of Thiiranes from Oxiranes in the Presence of β‐Cyclodextrin in Water
Authors: Srilakshmi Krishnaveni N. , Surendra K. , Somi Reddy M. , Nageswar Y. V. D. , Rama Rao K.
Published: April 2004

A mild and highly efficient, user‐friendly procedure has been developed for the conversion of oxiranes to thiiranes under supramolecular catalysis in the presence of β‐cyclodextrin in water at ambient temperature in excellent yields. The use of β‐cyclodextrin in this transformation overcomes the use of heavy metal halides as promoters and chlorinated hydrocarbons and other hazardous organic solvents.
The Absolute Configuration of the Products of the Enantioselective Rhodium(I)/BINAP‐Catalyzed Enyne Cyclization
Authors: Hashmi A. Stephen K. , Haufe Patrick , Rivas Nass Andreas , Bats Jan W.
Published: April 2004

The absolute configuration of the product 7 obtained from a rhodium‐catalyzed enyne cyclization of 6 with the (R)‐BINAP ligand was determined by anomalous diffraction in the X‐ray crystal structure analysis.
Model of adsorption–reaction–desorption in a swarm of spheroidal particles
Authors: Coutelieris F. A. , Burganos V. N. , Payatakes A. C.
Published: April 2004

The mass transport problem from a Newtonian fluid to a swarm of prolate or oblate spheroidal adsorbing particles under creeping flow conditions is considered here. The spheroidal‐in‐cell model is used for the analytical description of the flow field within the swarm. A realistic adsorption–reaction–desorption mechanism is used to describe the adsorption of mass on the particle surface, instead of the assumption of instantaneous adsorption that has been adopted previously. The convective diffusion equation accompanied by the appropriate boundary conditions is solved analytically for the case of high Peclet numbers and numerically for the low ones. In both cases, analytical expressions for the overall Sherwood number, the adsorption rate, and the mass transport coefficient were obtained. It was found that the adsorption rate is higher for oblate shapes and for diffusional, instead of convectional, environments. Finally, the assumption of instantaneous adsorption leads to values for the overall Sherwood number and the adsorption efficiency that are 15–50% lower and 10–35% higher, respectively, than those obtained by using the more realistic adsorption–reaction–desorption model. © 2004 American Institute of Chemical Engineers AIChE J, 50: 779–785, 2004
New sorbents for desulfurization of diesel fuels via π‐complexation
Authors: Hernández‐Maldonado Arturo J. , Yang Ralph T.
Published: April 2004

Desulfurization of a commercial diesel fuel by different adsorbents was studied in a fixed‐bed adsorber operated at ambient temperature and pressure. In general, the adsorbents tested for total sulfur adsorption capacity at breakthrough followed the order: AC/Cu(I)‐Y > Cu(I)‐Y > Selexsorb® CDX (alumina) > CuCl/γ‐Al2O3 > activated carbon > Cu(I)‐ZSM‐5. The best adsorbent, AC/Cu(I)‐Y (layered bed of 15 wt % activated carbon followed by Cu(I)Y), is capable of producing 30 cm3 of diesel fuel per gram of adsorbent with a weighted average content of 0.15 ppmw‐S, and about 20 cm3 of diesel fuel per gram of adsorbent with a weighted average content of 0.06 ppmw‐S. These low‐sulfur fuels are suitable for fuel cell applications. The added layer of carbon not only delayed the sulfur breakthrough significantly but also sharpened the sulfur wavefronts. GC‐FPD results showed that the π‐complexation sorbents selectively adsorbed highly substituted thiophenes, benzothiophenes, and dibenzothiophenes from diesel, which is not possible with conventional hydrodesulfurization (HDS) reactors. The high sulfur selectivity and high sulfur capacity of Cu(I)Y were because of π‐complexation. © 2004 American Institute of Chemical Engineers AIChE J, 50: 791–801, 2004
Chlorophenol exposure in harbor workers exposed to river silt aerosols
Authors: Radon Katja , Wegner Ralf , Heinrich‐Ramm Regine , Baur Xaver , Poschadel Bernd , Szadkowski Dieter
Published: April 2004

Objectives

While dredging the river Elbe in the harbor of Hamburg, workers are potentially exposed to river silt aerosols containing organic compounds. The aim of this cross‐sectional study was to determine the internal load of chlorophenols in exposed workers.

Methods

Eighty‐four exposed workers and eighty‐four unexposed office workers were examined. Urinary samples were analyzed for dichlorophenols, trichlorophenols, tetrachlorophenols, and pentachlorophenol (PCP).

Results

For exposed workers, more than 2/3 of the urinary samples were above detection limit for 2,5‐dichlorophenol, 2,4/3,4‐dichlorophenol, 2,4,6‐trichlorophenol, and PCP. Harbor workers had significantly higher median levels of 2,5‐dichlorophenol (0.6 vs. 0.4 µg/g creatinine) and PCP (1.4 vs. 1.0 µg/g creatinine) as compared to unexposed subjects. These differences remained statistically significant after adjustment for age, smoking habits, and fish consumption.

Conclusion

Harbor workers in the harbor of Hamburg have a statistically significant higher internal load of chlorophenols than the general population. However, the internal load is within the range of exposure reported from the general population. Therefore, even though chlorophenols are found in the river silt these exposures do not seem to be the major source of the internal load among workers in the harbor of Hamburg. Am. J. Ind. Med. 45:440–445, 2004. © 2004 Wiley‐Liss, Inc.
Involuntary job loss as a risk factor for subsequent myocardial infarction and stroke: Findings from The Health and Retirement Survey
Authors: Gallo William T. , Bradley Elizabeth H. , Falba Tracy A. , Dubin Joel A. , Cramer Laura D. , Bogardus Sidney T. , Kasl Stanislav V.
Published: April 2004

Background

The role of stress in the development of cardiovascular disease is well established. Previous research has demonstrated that involuntary job loss in the years immediately preceding retirement can be a stressful life event shown to produce adverse changes in physical and affective health. The objective of this study was to estimate the risk of myocardial infarction (MI) and stroke associated with involuntary job loss among workers nearing retirement in the United States.

Methods

We used multivariable survival analysis to analyze data from the first four waves of the Health and Retirement Survey (HRS), a nationally representative sample of older individuals in the US. The analytic sample includes 457 workers who experienced job loss and a comparison group of 3,763 employed individuals.

Results

The results indicate that involuntary job loss is not associated with subsequent risk of MI (adjusted HR = 1.89; 95% CI = 0.91, 3.93); the risk of subsequent stroke associated with involuntary job loss is more than double (adjusted HR = 2.64; 95% CI = 1.01, 6.94).

Conclusions

Our findings present new data to suggest that involuntary job loss should be considered as a plausible risk factor for subsequent cardiovascular and cerebrovascular illness among older workers. Am. J. Ind. Med. 45:408–416, 2004. © 2004 Wiley‐Liss, Inc.
An assessment of the effects of increased regulatory enforcement and legislative reform on occupational hearing loss workers' compensation claims: Oregon 1984–1998
Authors: McCall Brian P. , Horwitz Irwin B.
Published: April 2004

Background

Hearing loss from occupational exposures is a serious and widespread problem. This study measured the outcomes that increased enforcement of regulations and legislative interventions had on hearing loss workers' compensation claims.

Methods

Workers' compensation claim data from Oregon was analyzed for the period of 1984–1998 to examine trends and severity of hearing loss claims. In 1987 and 1990, Oregon enacted legislative reforms to improve enforcement and promulgation of safety standards in the state. This study examined hearing loss claims between the periods of pre‐ and post‐legislative reforms.

Results

It was found that hearing loss claims decreased significantly following the legislative reforms, although the average cost per claim increased. Age and tenure effects, and evidence of moral hazard were also discovered.

Conclusions

Increased enforcement of regulations and legislative interventions by Oregon improved working conditions leading to occupational hearing loss. Nevertheless, hearing loss remains problematic, and continued efforts are required to improve worker safety. Am. J. Ind. Med. 45:417–427, 2004. © 2004 Wiley‐Liss, Inc.
Duplication of the distal long arm of chromosome 15: Report of three new patients and review of the literature
Authors: Roggenbuck Jennifer A. , Mendelsohn Nancy J. , Tenenholz Beverly , Ladda Roger L. , Fink James M.
Published: April 2004

Patients with trisomies or duplications of distal 15q have rarely been reported in the literature. Previous authors [Zollino et al., 1999: Am J Med Genet 87:391–394] have described a distal 15q trisomy syndrome, including the unusual features of prenatal overgrowth, tall stature, macrocephaly, and craniosynostosis. We report three new patients with a duplication of 15q24‐q26.3; features common to the two surviving patients include ptosis, small size, and developmental delay. None of these patients had craniosynostosis or overgrowth. We propose that the previously described distal 15q trisomy syndrome [Zollino et al., 1999: Am J Med Genet 87:391–394] may result from specific disruption of a gene linked to 15q25, rather than partial trisomy for the region. © 2003 Wiley‐Liss, Inc.
Does autosomal dominant pseudoxanthoma elasticum exist?
Authors: Plomp Astrid S. , Hu Xiaofeng , de Jong Paulus T.V.M. , Bergen Arthur A.B.
Published: April 2004

Pseudoxanthoma elasticum (PXE) is a progressive disorder of elastic fibers in skin, eyes, and arterial walls. It is caused by mutations in the ABCC6 gene. Most patients are sporadic cases. The majority of familial cases show autosomal recessive (AR) inheritance, but autosomal dominant (AD) inheritance has also been reported. We reviewed the literature on AD PXE and we studied in detail, both clinically and by DNA studies, a selection of potentially AD pedigrees from our patient population consisting of 59 probands and their family members. Individuals were considered to have definite PXE if they had two of the following three criteria: characteristic ophthalmologic signs, characteristic dermatologic signs, and a positive skin biopsy. In the literature we found only three families with definite PXE in two successive generations and no families with definite PXE in three or more generations. Our own data set comprised three putative AD families. Extensive DNA studies revealed a mutation in only one ABCC6 allele in the patients of these families. Only one of our families showed definite PXE in two generations. Linkage studies revealed that pseudodominance was unlikely in this family. In the other two families AD PXE could not be confirmed after extensive clinical examinations and application of our criteria, since definite PXE was not present in two or more generations. Conclusion: the inheritance pattern in PXE usually is AR. Part of the phenotype in family members of PXE patients might be due to expression in heterozygous carriers of an AR disease. AD inheritance in PXE may exist, but is both after careful literature study and in our patient material much rarer than previously thought. © 2003 Wiley‐Liss, Inc.
Cerebellum—small brain but large confusion: A review of selected cerebellar malformations and disruptions
Authors: Boltshauser Eugen
Published: April 2004

Defining and classifying congenital disorders of the cerebellum can be difficult and confusing. One reason is that some abnormalities called “malformations” are not truly (primary) developmental malformations. This applies to Chiari I “malformations” as well as to Chiari II “malformations.” The latter results mainly from a prenatal cerebrospinal fluid (CSF) leak. Also disruptive cerebellar lesions are not uncommon, examples being the “vanishing cerebellum” in myelomeningocele, cerebellar lesions in very low birth weight prematurely born infants, unilateral cerebellar hypoplasia/aplasia, and probably some instances of cerebellar agenesis (CA). The cerebellar hypoplasias consist of a heterogeneous group of inherited and prenatally acquired conditions. The concept of pontocerebellar hypoplasias will need to be expanded beyond the two main types (PCH‐1 and PCH‐2), and demonstrate that a classification system of cerebellar malformations cannot be based on neuroimaging criteria only. Additional studies are expected to show that this also applies to the molar tooth sign, which was initially described in Joubert syndrome (JS). The JS is the prototype of midhindbrain malformation, but its delineation is still unsolved. JS may well be an overdiagnosed entity; many cases likely not having JS are on record. Rhombencephalosynapsis (RS) has been increasingly diagnosed with the advent of neuroimaging. No familial cases have been observed. Although many affected individuals have variable impairments, RS can be found in children with normal cognitive function. In this review, some of the cerebellar anomalies are briefly discussed. © 2004 Wiley‐Liss, Inc.
Cost of fetal alcohol spectrum disorders
Authors: Lupton Chuck , Burd Larry , Harwood Rick
Published: April 2004

Fetal alcohol syndrome (FAS) is a common identifiable teratogenic cause of mental retardation, neurological deficit, mental disorders, and developmental disabilities. Accurate estimates of the cost of care for persons with FAS are essential for appropriate funding of health care, developmental disabilities services, special education, and other service systems, as well as prioritizing funding of public health prevention efforts. The cost of care for individuals with FAS can be conceptualized as the annual cost of care for one person or a population, or as the lifetime cost of care for an individual. Annual cost estimates for the United States range from $75 million in 1984 to $4.0 billion in 1998. Estimates of lifetime cost vary from $596,000 in 1980 to $1.4 million in 1988. After adjustments for changes in inflation and population, 2002 estimates of total annual cost and lifetime cost are higher. FAS is increasingly being recognized as a large public health problem with high potential for the prevention of future cases and for the prevention of excess disability and premature mortality in persons who are affected. Each day, from 6–22 infants with FAS are born in the United States, and as many as 87–103 more are born with other impairments resulting from prenatal alcohol exposure. Updated and improved cost data on FAS should be a research priority. © 2004 Wiley‐Liss, Inc.
Axonal protection using flecainide in experimental autoimmune encephalomyelitis
Authors: Bechtold David A. , Kapoor Raju , Smith Kenneth J.
Published: April 2004

Axonal degeneration is a major cause of permanent neurological deficit in multiple sclerosis (MS), but no current therapies for the disease are known to be effective at axonal protection. Here, we examine the ability of a sodium channel–blocking agent, flecainide, to reduce axonal degeneration in an experimental model of MS, chronic relapsing experimental autoimmune encephalomyelitis (CR‐EAE). Rats with CR‐EAE were treated with flecainide or vehicle from either 3 days before or 7 days after inoculation (dpi) until termination of the experiment at 28 to 30 dpi. Morphometric examination of neurofilament‐labeled axons in the spinal cord of CR‐EAE animals showed that both flecainide treatment regimens resulted in significantly higher numbers of axons surviving the disease (83 and 98% of normal) compared with controls (62% of normal). These findings indicate that flecainide and similar agents may provide a novel therapy aimed at axonal protection in MS and other neuroinflammatory disorders.
Cu2+ toxicity inhibition of mitochondrial dehydrogenases in vitro and in vivo
Authors: Sheline Christian T. , Choi Dennis W.
Published: April 2004

Wilson's disease results from mutations in the P‐type Cu2+‐ATPase causing Cu2+ toxicity. We previously demonstrated that exposure of mixed neuronal/glial cultures to 20μM Cu2+ induced ATP loss and death that were attenuated by mitochondrial substrates, activators, and cofactors. Here, we show differential cellular sensitivity to Cu2+ that was equalized to 5 μM in the presence of the copper exchanger/ionophore, disulfiram. Because Cu2+ facilitates formation of oxygen radicals (ROS) which inhibit pyruvate dehydrogenase (PDH) and alpha‐ketoglutarate dehydrogenase (KGDH), we hypothesized that their inhibition contributed to Cu2+‐induced death. Toxic CU2+ exposure was accompanied by early inhibition of neuronal and hepatocellular PDH and KGDH activities, followed by reduced mitochondrial transmembrane potential, ΔΨM. Thiamine (1–6mM), and dihydrolipoic acid (LA, 50μM), required cofactors for PDH and KGDH, attenuated this enzymatic inhibition and subsequent death in all cell types. Furthermore, liver PDH and KGDH activities were reduced in the Atp7b mouse model of Wilson's disease prior to liver damage, and were partially restored by oral thiamine supplementation. These data support our hypothesis that Cu2+‐induced ROS may inhibit PDH and KGDH resulting in neuronal and hepatocellular death. Therefore, thiamine or lipoic acid may constitute potential therapeutic agents for Wilson's disease.
Magnetic resonance imaging of labeled T‐cells in a mouse model of multiple sclerosis
Authors: Anderson Stasia A. , Shukaliak‐Quandt Jacqueline , Jordan Elaine K. , Arbab Ali S. , Martin Roland , McFarland Henry , Frank Joseph A.
Published: April 2004

Multiple sclerosis (MS) is a T cell–mediated autoimmune disease with early lesions characterized by mononuclear cellular infiltrate, edema, demyelination, and axonal loss that contribute to the clinical course of the disease. Experimental autoimmune encephalomyelitis (EAE) in the mouse is a valuable model with a similar disease course to relapsing‐remitting MS. The ability to detect the migration of encephalitogenic T cells into the central nervous system in EAE and MS would provide key information on these cells role in the development of lesions observed on magnetic resonance imaging (MRI). T cells were labeled for detection by magnetic resonance imaging using Food and Drug Administration–approved, superparamagnetic iron oxide nanoparticles (Ferumoxides) complexed to poly‐L‐Lysine (FE‐PLL). EAE was induced by adoptive transfer of either labeled or unlabeled T cells. After disease onset, FE‐PLL–labeled T cells were detected in the mouse spinal cord using in vivo and ex vivo cellular MRI. Excellent correlation was seen between MRI‐visible lesions in the spinal cord and histopathology. The results demonstrate that T cells labeled with FE‐PLL can induce EAE disease and can be detected in vivo in the mouse model. The magnetic labeling of cells opens the possibility of monitoring specific cellular phenotypes or pharmacologically or genetically engineered cells by MRI.
Graft copolymerization of acrylamide onto carboxymethylcellulose with the xanthate method
Authors: El‐Hady Bothaina Abd , Ibrahim Maha M.
Published: April 2004

Acrylamide was grafted to an xanthate mixture of carboxymethylcellulose with a sodium bisulfate/ammonium persulfate redox initiator system in water, sodium hydroxide, potassium hydroxide, and dioxane at 40, 50, 60, 70, and 80°C during a reaction period of 2 h. The grafted polymer and homopolymer were isolated with diethyl ether from the reaction mixture, dried, and weighed. The grafted polymer was characterized with IR and mass spectrometry methods, and the microscopic morphology was detected with electron scanning microscopy. The graft level percentage distinctly increased with the use of sodium hydroxide, potassium hydroxide, and dioxane over that of a reaction carried out completely in an aqueous medium. Also, the graft level decreased as the reaction temperature increased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 271–278, 2004
Synthesis and properties of 4‐(ω‐methoxyoligodimethylsiloxanyl)butyl maleate: A new surfmer
Authors: Kohut A. M. , Hevus O. I. , Voronov S. A.
Published: April 2004

Anionic reactive maleate with hydrophobic oligosiloxane chain was synthesized to use as a stabilizer in the batch and seeded emulsion polymerization of traditional monomers (acrylates, methacrylates, styrene, etc.). Polymerizable surfactant is obtained in a three‐step synthesis, starting from the anionic polymerization of cyclic siloxanes, followed by the silylation of methanol with the obtained cyclic oligomer, and finishing with the acylation of the linear oligomer by maleic anhydride. The improved technique of the synthesis of 4‐chlorobutoxydimethylchlorosilane, one of the initial substances for obtaining siloxane monomer, was elaborated. The anionic polymerization of octamethylcyclotetrasiloxane using cyclic alkoxysilane was carried out to form siloxane cyclic oligomer for the first time. The chemical structure of the monomer synthesized was confirmed by IR spectroscopy and functional analysis. Critical micelle concentration of the obtained surfactant was measured. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 310–313, 2004
1, 2, 4‐Triazine N‐oxide Derivatives: Studies as Potential Hypoxic Cytotoxins. Part II.
Authors: Cerecetto Hugo , González Mercedes , Onetto Silvia , Saenz Patricia , Ezpeleta Olga , de Ceráin Adela López , Monge Antonio
Published: April 2004

New 1, 2, 4‐Triazine N‐oxide and N, N′‐dioxide derivatives were synthesized in order to obtain compounds as selective hypoxic cell cytotoxins. The starting heterocycles have been prepared using a standard microwave oven in a clean and good‐yielded process. The reactivity of methyl‐1, 2, 4‐triazine N4‐oxide and N1, N4‐dioxide with different electrophilic agents has been studied. The desired products were obtained only when iminium electrophiles were employed. The regioselectivity of this process has been studied by means of experimental and theoretical (at ab initio level) procedures. Theoretically was expected that the most stable intermediates where the benzylic‐like anion from position 5. A fact which agreed with the experimental observed regioselectivity. The new compounds were tested for their cytotoxicity in oxia and hypoxia. Some of them proved to be less active in hypoxic conditions than tirapazamine, 3‐amino‐benzo[1, 2‐e]1, 2, 4‐triazine N1, N4‐dioxide. Derivative 19, 6‐methyl‐5‐[2‐(5‐nitrothienyl)ethenyl)‐1, 2, 4‐triazine N4‐oxide, was the most cytotoxic compound, but it was non‐selective.
1, 2, 4‐Triazine N‐oxide Derivatives: Studies as Potential Hypoxic Cytotoxins. Part III
Authors: Cerecetto Hugo , González Mercedes , Risso Mariela , Saenz Patricia , Olea‐Azar Claudio , Bruno Ana M. , Azqueta Amaia , de Ceráin Adela López , Monge Antonio
Published: April 2004

New 5‐(2‐arylethenyl)‐1, 2, 4‐triazine N‐oxide and N, N′‐dioxide derivatives were synthesized in order to obtain compounds as selective hypoxic cell cytotoxins. The desired products were obtained when the 5‐methyl heterocycle reacted with the corresponding iminium electrophiles. The new compounds were tested for their cytotoxicity in oxia and hypoxia. Some of them proved to be less active in hypoxic conditions than Tirapazamine, 3‐aminobenzo[1, 2‐e]1, 2, 4‐triazine N1, N4‐dioxide. Derivative 11, 6‐methyl‐5‐[2‐(5‐nitrofuryl)ethenyl)‐1, 2, 4‐triazine N4‐oxide, was the most cytotoxic compound, but it was non‐selective. Some derivatives were studied as DNA‐binding agents in oxic conditions showing poor affinity for this biomolecule. This result showed that the cytotoxic activity in oxia is DNA damage not dependent. Electrochemical and ESR spectroscopy studies were performed in order to determine the ability of compounds to produce radicals and the relation of these in the mechanism of cytotoxicity.
Analysis of economic time series: effects of extremal observations on testing heteroscedastic components
Authors: Grossi Luigi , Laurini Fabrizio
Published: April 2004

Macroeconomic and financial time series are often tested for the presence of non‐linearity effects. Sometimes, small patches of extremal observations may wrongly influence non‐linearity tests. In this paper, a robust analysis of the Lagrange multiplier (LM) test for GARCH components is suggested. With Monte‐Carlo simulation we show that extreme observations might cause over‐estimation of the number of GARCH components, with the main contribution consisting by introducing the forward search method into the GARCH model family. Using robust estimators of regression coefficients and graphical displays of results, the effect of influential observations on estimates can be efficiently monitored. Analysing macroeconomic and financial time series we show that identifying the order of a GARCH model can be unduly influenced by a few isolated large values, and extremal observations affectp‐values andt‐statistics in an unexpected manner. Copyright © 2004 John Wiley & Sons, Ltd.
Modelling the process of incoming problem reports on released software products
Authors: Jongbloed Geurt , Verbaken Tonny
Published: April 2004

For big software developing companies, it is important to know the amount of problems of a new software product that are expected to be reported in a period after the date of release, on a weekly basis. For each of a number of past releases, weekly data are present on the number of such reports. Based on the type of data that is present, we construct a stochastic model for the weekly number of problems to be reported. The (non‐parametric) maximum likelihood estimator for the crucial model parameter, the intensity of an inhomogeneous Poisson process, is defined. Moreover, the expectation maximization algorithm is described, which can be used to compute this estimate. The method is illustrated using simulated data. Copyright © 2004 John Wiley & Sons, Ltd.
Different embryo‐fetal toxicity effects for three VLA‐4 antagonists
Authors: Crofts F. , Pino M. , DeLise B. , Guittin P. , Barbellion S. , Brunel P. , Potdevin S. , Bergmann B. , Hofmann T. , Lerman S. , Clark R.L.
Published: April 2004

BACKGROUND: VLA‐4 (Very late antigen 4, integrin α4β1) plays an important role in cell‐cell interactions that are critical for development. Homozygous null knockouts of the α4subunit of VLA‐4 or VCAM‐1 (cell surface ligand to VLA‐4) in mice result in abnormal placental and cardiac development and embryo lethality. Objectives of the current study were to assess and compare the teratogenic potential of three VLA‐4 antagonists. METHODS: IVL745, HMR1031, and IVL984 were each evaluated by the subcutaneous route in standard embryo‐fetal developmental toxicity studies in rats and rabbits. IVL984 was also evaluated in mice. Fetuses were examined externally, viscerally, and skeletally. RESULTS: IVL745 did not cause significant maternal or fetal effects at doses up to 100 or 250 mg/kg/day in rats or rabbits, respectively. HMR1031 treatment resulted in marked maternal toxicity and slight fetal toxicity at the highest tested doses of 200 and 75 mg/kg/day in rats and rabbits, respectively. HMR1031 embryo‐fetal effects consisted of slightly lower body weight and crown‐rump length in rats and minor sternebral defects in rabbits. IVL984 treatment resulted in minimal maternal effects at doses up to 40, 15, and 100 mg/kg/day in rats, rabbits, and mice, respectively (excluding abortions in rabbits). However, marked developmental effects were observed at the lowest tested IVL984 doses, 1, 0.2, and 3 mg/kg/day in rats, rabbits, and mice, respectively. IVL984 embryo‐fetal effects consisted of increased total post‐implantation loss due to early resorptions and high incidences of cardiac malformations and skeletal malformations and/or variations. Notably, spiral septal defects were observed in up to 76% of rat fetuses and up to 58% of rabbit fetuses. CONCLUSIONS: Dramatic differences in teratogenic potential were observed: IVL745 was not teratogenic, HMR1031 caused slight embryo‐fetal effects at maternally‐toxic doses, and IVL984 was a potent teratogen at doses where direct maternal toxicity was limited to abortions in rabbits. Prominent effects of IVL984 included embryo lethality and cardiac malformations including spiral septal defects in three species. Birth Defects Res B 71:55–68, 2004. © 2004 Wiley‐Liss, Inc.
Methanol exposure during gastrulation causes holoprosencephaly, facial dysgenesis, and cervical vertebral malformations in C57BL/6J mice
Authors: Rogers John M. , Brannen Kimberly C. , Barbee Brenda D. , Zucker Robert M. , Degitz Sigmund J.
Published: April 2004

BACKGROUND: Exposure of pregnant outbred CD‐1 mice to methanol during the period of gastrulation results in exencephaly, cleft palate, and cervical vertebra malformations [Rogers and Mole, Teratology 55: 364, 1997], while inbred C57BL/6J mice are sensitive to the teratogenicity of ethanol. C57BL/6J fetuses exhibit the holoprosencephaly spectrum of malformations after maternal exposure to ethanol during gastrulation, but the sensitivity of C57BL/6J mice to methanol‐induced teratogenesis has not been previously described. METHODS: Pregnant C57BL/6J mice were administered two i.p. injections totaling 3.4 or 4.9 g/kg methanol or distilled water four hrs apart on gestation day ‘GD’ 7. On GD 17, litters were examined for numbers of live, dead and resorbed conceptuses, fetuses were weighed as a litter and examined externally, and all fetuses were double stained for skeletal analysis. RESULTS:No maternal intoxication was apparent, but the high dosage level caused a transient deficit in maternal weight gain. The number of live fetuses per litter was reduced at both dosages of methanol, and fetal weight was lower in the high dosage group. Craniofacial defects were observed in 55.8% of fetuses in the low dosage group and 91.0% of fetuses in the high dosage group, including micro/anophthalmia, holoprosencephaly, facial clefts and gross facial angenesis. Skeletal malformations, particularly of the cervical vertebrae, were observed at both dosages of methanol, and were similar to those previously reported in the CD‐1 mouse following methanol exposure. CONCLUSIONS: The types of craniofacial malformations induced in the C57BL/6J mouse by methanol indicate that methanol and ethanol have common targets and may have common modes of action. Birth Defects Res B 71:80–88, 2004. Published 2004 Wiley‐Liss, Inc.
Cardiac abnormalities induced by zinc deficiency are associated with alterations in the expression of genes regulated by the zinc‐finger transcription factor GATA‐4
Authors: Duffy J.Y. , Overmann G.J. , Keen C.L. , Clegg M.S. , Daston G.P.
Published: April 2004

Zinc (Zn) deficiency during pregnancy results in a wide variety of developmental abnormalities. The objective of this study was to determine if expression of cardiac developmental genes regulated by Zn‐finger transcription factors could be modulated during dietary Zn deficiency. Rats were fed 0.5 (low Zn) or 90 (controls) µg Zn/g diet throughout pregnancy. Fetal development was examined and RNA isolated at gestation day (GD) 13 and 20. Cardiac abnormalities were detected at GD 20 in 82% of fetuses from dams fed low Zn diets compared with only 2% in controls. Cardiac developmental gene expression regulated by the Zn‐finger transcription factor, GATA‐4, was measured by quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR). In GD 13 and 20 hearts, two genes critical for heart development, α‐myosin heavy chain (α‐MHC) and cardiac troponin I (cTnI), were down‐regulated in Zn‐deficient fetuses. Expression of α‐MHC was 66 and 40% lower at GD 13 and 20, respectively, in fetuses from dams fed low Zn diets compared with fetuses from control dams (p<0.05). Fetal cardiac TnI RNA levels were reduced 40 and 45% at GD 13 and 20 in the Zn‐deficient group compared with controls (p<0.05). Fetal cardiac transcript levels of GATA‐4 and MHox, a gene regulated by a helix‐loop‐helix transcription factor, whose expressions are not Zn‐dependent, were unaffected by diet. These data indicated that alterations in gene regulation might be an underlying mechanism of cardiac abnormalities. Dysfunction of other Zn‐dependent transcription factors may be an integral part of the extensive teratogenesis associated with Zn deficiency. Birth Defects Res B 71:102–109, 2004. © 2004 Wiley‐Liss, Inc.
Preface: Biom. J. Supplement 1/2004
Authors: Becher Heiko , Brenner Hermann , Brunner Edgar , Chang‐Claude Jenny , Edler Lutz , Giani Guido , Hense Hans‐Werne , Kauermann Göran , Kieser Meinhard , Kohlmann Thomas , Kurth Bärbel‐Maria , Mansmann Ulrich , Röhmel Joachim , Victor Norbert , Wichmann Heinz‐Erich
Published: April 2004

This special volume of the Biometrical Journal contains the Abstracts of the joint meeting of the German Region of the International Biometric Society (IBS‐DR) and the German Association of Epidemiology (Deutsche Arbeitsgemeinschaft für Epidemiologie, DAE) which takes place in Heidelberg, Germany, on March 16‐19, 2004. The meeting covers a wide range of topics from both fields. We, the program committee, hope that this abstract book will contribute to a further growth of both fields in Germany and to further collaborations between research groups on national and international level.

We thank the Publisher, WILEY‐VCH, and in particular the Senior Publishing Editor, Dr. Hans‐Joachim Kraus, for the excellent collaboration, and Dr. Michael Löw and Isabel Lerch, Heidelberg, for the careful editing of the total volume.
Spectroscopic behavior of copper complexes of nonsteroidal anti‐inflammatory drugs
Authors: Trinchero A. , Bonora S. , Tinti A. , Fini G.
Published: April 2004

The proposed curative properties of Cu‐based nonsteroidal anti‐inflammatory drugs (NSAIDs) have led to the development of numerous Cu(II) complexes of NSAIDs with enhanced anti‐inflammatory activity. Crystalline complexes, Cu(II)–NSAID (ibuprofen, naproxen, tolmetin, and diclofenac), with a carboxylic function have been studied by means of infrared and Raman spectroscopy. All NSAIDs bind the metal through the carboxylate group. On the basis of the comparison between the wavenumber of the COO‐ group vibrations and Δν (νasimmCOO‐ – νsimmCOO‐) between Na salts and Cu(II) complexes, conclusions on the probable structure of the complexes have been drawn. The spectroscopic data support the formation of dimeric [Cu2L4(H2O)2] complexes in which the COO‐ group behaves as a bridging bidentate ligand. The low wavenumber region of the Raman spectrum provided information on Cu–O and Cu–Cu bonds in the complexes. Thermogravimetric results gave further support to the vibrational data. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Randomized clinical trial of low molecular weight heparin with thigh-length or knee-length antiembolism stockings for patients undergoing surgery
Authors: Howard A , Zaccagnini D , Ellis M , Williams A , Davies A H , Greenhalgh R M
Published: April 2004

Background

This was a randomized clinical trial to determine the efficacy and safety of a ‘blanket’ protocol of low molecular weight heparin (LMWH) and the best length of antiembolism stocking, for every patient requiring surgery under general anaesthesia.

Methods

Of 426 patients interviewed, 376 agreed to be randomized to receive one of three types of stocking: thigh-length Medi thrombexin® climax™ (Medi UK, Hereford, UK), knee-length thrombexin® climax™ and thigh-length Kendall T.E.D.™ (Tyco Healthcare UK, Redruth, UK). All patients received LMWH thromboprophylaxis. Duplex ultrasonography was used to assess the incidence of postoperative deep vein thrombosis (DVT).

Results

No postoperative DVT occurred in 85 patients at low or moderate risk. Nineteen DVTs occurred, all in the 291 high-risk patients: two with the Medi thigh-length stockings, 11 with the Medi knee-length stockings (odds ratio 0·18 (95 per cent confidence interval 0·04 to 0·82); P = 0·026) and six with the Kendall T.E.D.™ thigh-length stockings. No patient developed a pulmonary embolism. Stocking groups were similar for age, sex, thromboembolic risk, type of operation and compliance. One significant bleeding complication occurred.

Conclusion

A single protocol comprising LMWH and thigh-length stockings abolished DVT in low- and moderate-risk patients, and reduced the rate of DVT to 2 per cent in high-risk patients.