bluuebunny/crossref_metadata_2025 huggingface dataset:
$K_{\rm L}\to \pi^0\nu\bar\nu$ AS A PROBE OF NEW PHYSICS
Authors: BRYMAN DOUGLAS , BURAS ANDRZEJ J. , ISIDORI GINO , LITTENBERG LAURENCE
Published: February 2006

We summarize the theoretical virtues of the rare [Formula: see text] decays and emphasize the unique role of [Formula: see text] in probing the nature of physics beyond the Standard Model, in particular concerning possible new sources of CP violation and flavor-symmetry breaking. A brief summary of the prospects for the measurement of the [Formula: see text] rate is also given.
NAMBU BRACKETS WITH CONSTRAINT FUNCTIONALS
Authors: TEĞMEN A.
Published: February 2006

If a Hamiltonian dynamical system with n degrees of freedom admits m constants of motion more than 2n-1, then there exist some functional relations between the constants of motion. Among these relations the number of functionally independent ones are s = m-(2n-1). It is shown that for such a system in which the constants of motion constitute a polynomial algebra closing in Poisson bracket, the Nambu brackets can be written in terms of these s constraint functionals. The exemplification is very rich and several of them are analyzed in the text.
NONCOMMUTATIVE METAFLUID DYNAMICS
Authors: MENDES A. C. R. , NEVES C. , OLIVEIRA W. , TAKAKURA F. I.
Published: February 2006

In this paper we define a noncommutative (NC) metafluid dynamics.1,2 We applied the Dirac's quantization to the metafluid dynamics on NC spaces. First class constraints were found which are the same obtained in Ref. 4. The gauge covariant quantization of the nonlinear equations of fields on noncommutative spaces were studied. We have found the extended Hamiltonian which leads to equations of motion in the gauge covariant form. In addition, we show that a particular transformation3 on the usual classical phase space (CPS) leads to the same results as of the ⋆-deformation with ν = 0. Besides, we have shown that an additional term is introduced into the dissipative force due to the NC geometry. This is an interesting feature due to the NC nature induced into model.
AN ALGORITHMIC APPROACH TO QUANTUM FIELD THEORY
Authors: DI PIERRO MASSIMO
Published: February 2006

The lattice formulation provides a way to regularize, define and compute the Path Integral in a Quantum Field Theory. In this paper, we review the theoretical foundations and the most basic algorithms required to implement a typical lattice computation, including the Metropolis, the Gibbs sampling, the Minimal Residual, and the Stabilized Biconjugate inverters. The main emphasis is on gauge theories with fermions such as QCD. We also provide examples of typical results from lattice QCD computations for quantities of phenomenological interest.
SYMMETRIES ASSOCIATED WITH SYMPLECTIC CURRENTS
Authors: TORRES DEL CASTILLO G. F. , LÓPEZ-VILLANUEVA A.
Published: February 2006

It is shown that the existence of the symplectic currents for the Maxwell, Einstein, Einstein–Maxwell, and Yang–Mills equations, can be derived from the invariance of the Lagrangian for the corresponding complexified linearized equations under multiplication of the field variables by a (global) phase factor.
NOVEL CMOS REALIZATIONS OF THE OPERATIONAL FLOATING CONVEYOR AND APPLICATIONS
Authors: HASSAN HASSAN M. , SOLIMAN AHMED M.
Published: February 2006

This paper presents novel CMOS realizations of the operational floating conveyor (OFC) based on novel block diagrams. It also introduces novel applications based on one of the proposed OFC realizations. The proposed OFC realization provides a wide bandwidth and a large gain bandwidth product. Hence, it exhibits wide bandwidth at higher gains. All the circuits in this paper are designed following a fair comparison criterion. The supply voltages are ±1.5 V . The reference DC current source IB is taken as 50 μA. The CMOS model for all circuits is identical. The transistor model is 0.5 μm CMOS process provided by MOSIS (AGILENT).
Moderate Alcohol Consumption and Diseases of the Gastrointestinal System: A Review of Pathophysiological Processes
Authors: Taylor Benjamin , Rehm Jürgen
Published: February 2006

Background/Aims: Alcohol drinking is responsible for a number of gastrointestinal diseases and cancers. Although heavy drinking episodes and chronic drinking are well linked to mechanisms of disease, moderate alcohol consumption and its effects are less well known. This review attempts to fill a gap in the literature surrounding moderate alcohol consumption. Methods: A systematic review of the English literature using PubMed was used. Results: A dose-response risk relationship exists between alcohol consumption and digestive disease risk. Acetaldehyde is the main factor in alcohol-related damage in moderate alcohol consumption and acts through numerous methods to exert damaging effects. Conclusion: Zero alcohol intake is recommended for lowest risk of alcohol-related digestive tract diseases and conditions. However, given the lowest overall mortality is associated with moderate drinking, moderate drinking with no bingeing episodes is recommended.
Animal Models and Their Results in Gastrointestinal Alcohol Research
Authors: Siegmund Sören V. , Haas Stephan , Singer Manfred V.
Published: February 2006

Alcohol-induced diseases of the gastrointestinal tract play an important role in clinical gastroenterology. However, the precise pathophysiological mechanisms are still largely unknown. Alcohol research depends essentially on animal models due to the fact that controlled experimental studies of ethanol-induced diseases in humans are unethical. Animal models have already been successfully applied to disclose and analyze molecular mechanisms in alcohol-induced diseases, partially by using knockout technology. Because of a lack of transferability of some animal models to the human condition, results have to be interpreted cautiously. For some alcohol-related diseases like chronic alcoholic pancreatitis, the ideal animal model does not yet exist. Here we provide an overview of the most commonly used animal models in gastrointestinal alcohol research. We will also briefly discuss the findings based on animal models as well as the current concepts of pathophysiological mechanisms involved in acute and chronic alcoholic damage of the esophagus, stomach, small and large intestine, pancreas and liver.
Treatment of Alcoholic Pancreatitis
Authors: Pfützer Roland H. , Schneider Alexander
Published: February 2006

Chronic pancreatitis is characterized by progressive and irreversible loss of pancreatic exocrine and endocrine function. The majority of cases in the Western world are related to alcohol consumption. Treatment of alcoholic chronic pancreatitis has been difficult, since the mechanisms of disease progression and the causes of pain are poorly understood. The conservative management of chronic pancreatitis focuses on (a) avoidance of precipitating factors such as alcohol and smoking; (b) treatment of pain, and (c) replacement of exocrine and endocrine function. There is a lack of good controlled, randomized treatment trials in alcoholic pancreatitis. However, there is good evidence that lifestyle changes, such as alcohol cessation, hamper progression of the disease. Conservative treatment of pain should be based on a stepwise approach; however, underlying causes such as pseudocysts may require endoscopic or surgical therapy. Treatment of exocrine insufficiency requires pancreatic enzyme supplementation and adjustment to several smaller meals per day, while treatment of endocrine insufficiency requires insulin treatment.
Molecular Mechanisms of Alcohol-Induced Hepatic Fibrosis
Authors: Siegmund Sören V. , Dooley Steven , Brenner David A.
Published: February 2006

Alcohol abuse is a major cause of liver fibrosis and cirrhosis in developed countries. Before alcoholic liver fibrosis becomes evident, the liver undergoes several stages of alcoholic liver disease including steatosis and steatohepatitis. Although the main mechanisms of fibrogenesis are independent of the etiology of liver injury, alcoholic liver fibrosis is distinctively characterized by a pronounced inflammatory response due to elevated gut-derived endotoxin plasma levels, an augmented generation of oxidative stress with pericentral hepatic hypoxia and the formation of cell-toxic and profibrogenic ethanol metabolites (e.g. acetaldehyde or lipid oxidation products). These factors, based on a complex network of cytokine actions, together result in increased hepatocellular damage and activation of hepatic stellate cells, the key cell type of liver fibrogenesis. Although to date removal of the causative agent, i.e. alcohol, still represents the most effective intervention to prevent the manifestation of alcoholic liver disease, sophisticated molecular approaches are underway, aiming to specifically blunt profibrogenic signaling pathways in liver cells or specifically induce cell death in activated hepatic stellate cells to decrease the scarring of the liver.
Treatment of Alcoholic Liver Disease
Authors: Bergheim Ina , McClain Craig J. , Arteel Gavin E.
Published: February 2006

Alcoholic liver disease (ALD) remains a major cause of morbidity and mortality worldwide. For example, the Veterans Administration Cooperative Studies reported that patients with cirrhosis and superimposed alcoholic hepatitis had a 4-year mortality of >60% (worse than many common cancers such as breast and prostate). The cornerstone for therapy for ALD is lifestyle modification, including drinking cessation and treatment of decompensation, if appropriate. Nutrition intervention has been shown to play a positive role on both an in-patient and out-patient basis. Corticosteroids are effective in selected patients with alcoholic hepatitis, and treatment with pentoxifylline appears to be a promising anti-inflammatory therapy. Recent studies have indicated anti-TNFα therapy, at least for alcoholic hepatitis. Some complementary and alternative medicinal agents, such as milk thistle and S-adenosylmethionine, may be effective in alcoholic cirrhosis. Treatment of the complications of ALD can improve the quality of life and, in some cases, decrease short-term mortality.
Alcohol and Hepatitis C
Authors: Jamal M. Mazen , Saadi Zainab , Morgan Timothy R.
Published: February 2006

Background/Aims: Alcohol use and hepatitis C are prominent risk factors for liver injury and this review offers the current understanding of each factor’s effects on liver disease. Methods: A Medline database search was preformed for English articles with a focus on alcohol, hepatitis C and liver disease. Article citations were also considered for further applicable articles, and the strongest studies were included in our review. Results: Up to 60% of patients with hepatitis C have a past history of alcohol use. In patients with hepatitis C, chronic alcohol consumption of more than 5 drinks/day increases the rate of liver fibrosis, risk for cirrhosis, hepatocellular carcinoma, and, possibly, death from liver disease. Numerous studies have further found that even moderate amounts of alcohol can be detrimental to hepatitis C patients. The prevalence of hepatitis C is higher in alcoholics with advanced liver disease than in alcoholics without liver disease. Also, recent alcohol use decreases the response rate to interferon treatment. Conclusions: Hepatitis C and alcohol use are often co-occurring risk factors for liver disease, and though their interaction is not clear, it is known that heavy drinking significantly promotes liver disease progression.
Tandem Repeats Polymorphism of MUC20 Is an Independent Factor for the Progression of Immunoglobulin A Nephropathy
Authors: Li Guisen , Zhang Hong , Lv Jicheng , Hou Ping , Wang Haiyan
Published: February 2006

MUC20, an upregulated novel gene in the renal tissues of patients with IgA nephropathy (IgAN), was recently identified. The variable number of tandem repeats (VNTR) polymorphism of the MUC20 gene was detected in several cell lines. In the present study, we investigated a possible association of MUC20 VNTR polymorphism with the clinical manifestations and progression in patients with IgAN. A total of 1,147 Chinese subjects, including 657 patients with IgAN and 490 geographically matched healthy controls, were involved in this investigation. One hundred and thirty-seven patients had been followed up for 60.6 ± 22.4 months. MUC20 VNTR polymorphism was genotyped by polymerase chain reaction amplification and confirmed by sequencing. The alleles were divided into two groups according to the repeat times of MUC20 VNTR, i.e. small alleles (VNTR repeat times ≤3) and large alleles (VNTR repeat times >3), and the genotypes of subjects were classified into SS, SL and LL groups. The frequencies of the alleles and genotypes of MUC20 VNTR polymorphisms did not differ between patients with IgAN and healthy controls. Additionally, there was no significant difference in the clinical features. Furthermore, IgAN patients with SL/LL genotypes had a higher risk of decline in renal function (odds ratio 20.9; 95% confidence interval 2.6–168.1; p = 0.004) than those with SS genotypes. The present study revealed that there is no association between the VNTR polymorphism of the MUC20 gene and the clinical manifestations in IgAN patients at the time of renal biopsy. However, IgAN patients with SL/LL genotypes had a higher risk of the progression to end-stage renal disease.
Role of Genetic Analyses in Cardiology
Authors: Priori Silvia G. , Napolitano Carlo
Published: February 2006

Genetic analysis can be performed to identify the molecular substrate of inherited arrhythmogenic diseases; however, the role of this information in helping the management of patients is still debated. Here, we support the view that the practical value of genetic analysis is different in the various inherited conditions and that it is strongly influenced by the amount of information available in each disease about genotype-phenotype correlations. In some diseases, clinical management of patients is profoundly affected by the type of the underlying genetic defect; therefore, in these conditions, there is a high priority to introduce genetic analysis into clinical practice. In the absence of genotype-phenotype correlations, genetic testing still can be very useful when there is a clinical advantage in establishing presymptomatic diagnosis or when screening of family members may point to reproductive counseling. Finally, there is a high priority for introducing genetic testing for those genetic diseases in which a limited number of genes allow a high yield of successfully genotyped patients. We have developed a “score” to compare the value of genetic testing in arrhythmogenic diseases and to convey our view that the clinical role of genetic analysis is different in the various inherited cardiomyopathies and channelopathies. Healthcare authorities should become responsive to the advancement of knowledge in this field and should help facilitate access to genotyping for families affected by those conditions in which genetic analysis provides useful information for clinical management.
Factor Structure of Psychopathy in Youth
Authors: Salekin Randall T. , Brannen Dia N. , Zalot Alecia A. , Leistico Anne-Marie , Neumann Craig S.
Published: February 2006

Psychopathy has traditionally been viewed as a two-factor construct composed of core personality and antisocial features. This two-factor model was called into question by Cooke and Michie. Specifically, Cooke and Michie proposed a three-factor model that divided the original first factor into interpersonal and affective factors. The traditional second factor was reduced to only including irresponsible and impulsive behaviors, thereby deemphasizing antisocial characteristics. Recently, Hare found evidence of a four-factor model that reincorporates antisocial items. The current study examined two-, three-, and four-factor structures in adolescent offenders ( N = 130) via confirmatory factor analyses. The results suggest that the two-factor model was a poor fit; however, three- and four-factor models evidenced good fit and were justifiable. These findings have important implications for the construct validity of the Psychopathy Checklist: Youth Version. Implications for potential developmental trajectories, dangerousness, and treatment are discussed.
A Play of Four Arenas
Authors: Luoma Mikko
Published: February 2006

Today’s rapidly changing business environment makes organizations pay special attention to the functioning of their internal processes. Among other things, the processes of management development (MD) are expected to reflect better the new competitive reality, which is characterized by dynamism, connectivity, non-linearity and emergent properties. This article studies MD in the light of complex adaptive systems (CAS), and presents key ideas of a systems approach to MD. The article elaborates a framework that combines MD’s situational context, developmental guidelines derived from the CAS theory, and examples of relevant MD practices. The framework offers MD professionals a practical means to assess and strengthen MD’s role in business. Furthermore, directions for future research on systems-based MD are brought up.
Role-play Teaching
Authors: Baruch Yehuda
Published: February 2006

Within the context of the ongoing debate on the relevance of the teaching approach to effective learning, the quality of teaching should be better understood. To help in this, the article presents a two-dimensional model of roles, based on three streams of knowledge—education, behavioural sciences and drama. It is a generic model, which proposes a conceptual framework for analysing, comparing and contrasting metaphorical masks that lecturers 2 may utilize in their teaching, with particular relevance for management education and learning. It clarifies what these roles are, and how they can be practised to improve the effectiveness of teaching and enhance learning. A number of cases demonstrate the descriptive and analytical power of the model.
Managing Trade-offs and Tensions between Knowledge Management Initiatives and Expertise Development Practices
Authors: Oshri Ilan , Pan Shan L. , Newell Sue
Published: February 2006

This article explores the trade-offs and tensions between knowledge management initiatives and expertise development practices. While studies of knowledge management and expertise development are abundant, there is no research that has addressed the inter-relationships between these two organizational practices. This article, therefore, addresses the following question: How does the introduction and implementation of a knowledge management initiative affect the development of engineer’s expertise within a firm? An in-depth case study of a company introducing new practices to promote knowledge transfer between projects in a fast-changing project environment is analysed. Based on the findings, we conclude that the introduced knowledge transfer initiative has upset the past harmony between expertise development and knowledge management practices.
Polydispersity Influence upon Magnetic Properties of Aggregated Ferrofluids
Authors: Holm Christian , Ivanov Alexey , Kantorovich Sofia , Pyanzina Elena
Published: February 2006

In the present paper we compare the static magnetic properties of a bidisperse ferrofluid obtained via computer simulations with the predictions of the theoretical chain model. At weak fields, the computer simulations showed a strong dependence of the magnetization on the concentration of large particles. When the latter is small the magnetization behavior is close to the one given by the modified mean field approach, but at higher concentrations of large particles the initial susceptibility increases significantly. This increase cannot be described in terms of the modified mean field model for the homogeneous system. A new theoretical approach for the description of the static magnetic properties of a bidisperse ferrofluid was developed. The theoretical predictions are in good agreement with the results of a recent computer simulation study.
Magnetic Fluid Layer on a Cylinder in a Traveling Magnetic Field
Authors: Zimmermann Klaus , Zeidis I. , Naletova V.A. , Turkov V.A. , Bachurin V. E.
Published: February 2006

The flow of a layer of an incompressible viscous magnetic fluid with a constant magnetic permeability on a cylinder under the action of a travelling magnetic field is analyzed. The strength of the magnetic field producing a sinusoidal travelling wave on the surface of a magnetic fluid is found. This flow can be used in designing mobile robots.
The Carboxymethyl Dextran Shell is an Important Modulator of Magnetic Nanoparticle Uptake in Human Cells
Authors: Schwalbe M. , Buske N. , Vetterlein M. , Höffken K. , Pachmann K. , Clement J. H.
Published: February 2006

In oncology and hematology the separation of tumor cells from healthy cells in peripheral blood is a vital problem. We could show previously, that enrichment of tumor cells from peripheral blood is possible by using magnetic nanoparticles with a carboxymethyl dextran (CMD) shell. Long-term storage of CMD nanoparticles eliminated the differential labeling of tumor cells and leukocytes which might be due to an alteration of the carboxymethyl dextran shell. Incubation of stored CMD nanoparticles with freshly prepared carboxymethyl dextran restored the differential labeling. In contrast, enzymatic degradation of the carboxymethyl dextran shell with dextranase abolished the cell-type specific labeling. Thus, an intact carboxymethyl dextran shell is crucial for the cell-type specific interaction of the CMD nanoparticles and living cells.
A Successful Strategy for the Production of Cationic Magnetoliposomes
Authors: De Cuyper M. , Caluwier D. , Baert J. , Cocquyt J. , Van de Meeren P.
Published: February 2006

The present work describes a strategy and the mechanistic background for synthesizing magnetoliposomes (MLs) in which the bi-layered coating is partly composed of positively charged lipids. In a first step, neutral MLs are prepared from zwitterionic phosphatidylcholine vesicles and magnetite nanocores stabilized with an anionic surfactant, and then incubated with cationic vesicles formed from phosphatidylcholine and dioleoyltrimethylammoniumpropane. During this latter step, spontaneous intermembrane lipid transfer occurs. After reaching an equilibrium state, the desired cationic MLs are captured from the mixture in a high-gradient magnetophoresis setup.
Magnetic Polymer Brushes: Towards Tailor-Made Stabilization of Magnetic Fluids by Surface-Initiated Polymerization
Authors: Gelbrich Thorsten , Feyen Mathias , Schmidt Annette M.
Published: February 2006

Novel surfactant-free magnetic fluids based on magnetite nanoparticles stabilized by a covalently attached polymeric brush were characterized in terms of their dispersion properties by DLS. We found that the molecular weight of the stabilizing surface-tethered polymeric arms has a direct impact on the hydrodynamic diameter d
h of the well-dispersed particles. An increase of d
h from 10 nm (octylcarboxylate-stabilized magnetite particles) to more than 100 nm for similar magnetite cores with a densely grafted poly(ε-caprolactone) (PCL) shell of 12300 g mol−1 is observed. The experimental results are compared to the expected values in the case of completely stretched polymeric chains.
Production and Characterisation of Ferromagnetic Nanoscale Metal Powders Produced by Laser Evaporation
Authors: Schaarschuch Rolf , Moras Konrad , Riehemann Werner , Brendebach Boris , Modrow Hartwig
Published: February 2006

Ferromagnetic metallic nanoscale particles were produced by laser evaporation of Co, Fe and Fe3Al targets with vapour condensation in nitrogen, argon or air. The composition and structure of the nanoscale powders were investigated by XRD and XAS. The Fe and Fe3Al powders condensed in nitrogen or argon consist mainly of the same phase as the targets. Small amounts of various oxides were found too. Condensation in air yields pure oxide nanopowders without metallic phases. From Co targets nanoscale particles with both fcc and hcp structure are obtained. With increasing aggregation gas pressure the mean diameter of the powders increases, leading to a higher saturation magnetisation of the coarser powders. The oxidation stability of the powders can be attributed to oxygen layers on the particles which were found to be 1–2 nm thick.
Dependence of Brownian Relaxation on the Volume Fraction and an External Field
Authors: Fischer B. , Wagner J. , Schmitt M. , Trieu V. , Hempelmann Rolf
Published: February 2006

CoxFe3−xO4 based ferrofluids were employed to study the dependence of the rotational diffusion on the concentration of magnetic particles and on a static external magnetic field. This influence is investigated in a frequency range 100 Hz ≤ f ≤ 700 kHz. With increasing volume fraction, the rotational motion is slowed down. The increase of the relaxation times can be described by an apparent increase of the effective viscosity originating from particle interactions. In a static external field, the rotation of large particles is trapped. Hence only the fraction of small particles is able to follow the ac-field and the magnetic relaxation appears to be faster. The critical particle size for a transition from free state into a trapped state depends on the strength of the static magnetic field.
Surface Waves and Rosensweig Instability in Isotropic Ferrogels
Authors: Bohlius Stefan , Brand Helmut R. , Pleiner Harald
Published: February 2006

We derive the dispersion relation of surface waves for isotropic magnetic gels in the presence of an external magnetic field normal to the free surface. Above a critical field strength surface waves become linearly unstable with respect to a stationary pattern of surface protuberances. This linear stability criterion generalizes that of the Rosensweig instability for ferrofluids by taking into account elasticity, additionally.
Characterization of the Grain Size in Ferromagnetic Colloids: Comparing Torsional-Pendulum Measurements with Standard Complementary Methods
Authors: Embs J. , Müller H. W. , Krill C. E. , Meyer F. , Natter H. , Müller B. , Wiegand S. , Lücke M. , Knorr K. , Hempelmann Rolf
Published: February 2006

A recently introduced shear-flow-free method for measuring the rotational viscosity of a resonantly forced torsional pendulum is used to determine the transverse magnetic relaxation time in magnetite and cobalt-based ferrofluids. From these data the average size of the ferromagnetic grains and their hydrodynamic diameter (core plus surfactant coating) are deduced under in-situ conditions, i.e. without diluting the sample. The reliability of the method is demonstrated by comparing the results with those of the complementary techniques of magneto-granulometry, X-ray diffraction, electron microscopy, and photon-correlation spectroscopy.
Structural and Magnetic Properties of Ni/NiOxide- and Co/CoOxide Core/Shell Nanoparticles and their possible Use for Ferrofluids
Authors: Schneider V. , Reinholdt A. , Kreibig U. , Weirich T. , Güntherodt G. , Beschoten B. , Tillmanns A. , Krenn H. , Rumpf K. , Granitzer P.
Published: February 2006

Ni- and Co-nanoparticles of average sizes of about 4 to 10 nm were produced by “physical” means with the cluster source LUCAS based upon laser evaporation into seeding gas and adiabatic expansion into an UHV experimentation chamber. They were deposited and subsequently oxidized in situ at about 400 °C.

The structures of the nanos were characterized by HRTEM and chemically analyzed by EFTEM. Clear core/shell structures were established with crystalline metallic core and crystalline oxide shell of final thickness of about 2 nm. In one sample it might be that the shell is amorphous.

An analysis of magnetic properties by SQUID was performed at temperatures between 5 and 300 K and for three different states of oxidation. Surprisingly strong influences of magnetic defects in the nominally (but probably incompletely saturated) antiferromagnetic oxide layers were observed which result in additional exchange anisotropy, in drastic exchange bias shifts of the hystereses and, in one sample, in a second hysteresis loop contribution. In all samples we found suppression of the superparamagnetic state.

The special sample with two loop contributions was numerically evaluated (by co-author H. Krenn).

In the final chapter a method is proposed how to transform these “physically” produced magnetic nanoparticles into a ferrofluid of well known composition.
Gravity Level Influence on a Laterally Heated Ferrofluid Submitted to an Oblique Strong Magnetic Field
Authors: Hennenberg Marcel , Weyssow Boris , Slavtchev S. , Aleksandrov V. , Scheid B.
Published: February 2006

A horizontal ferrofluid layer is submitted to a lateral heating and to a strong oblique magnetic field. For a thin enough layer, the steady state solution is the product of the classical solution corresponding to the usual Newtonian fluid submitted to a lateral gradient of temperature, times a modulating factor. This last accounts for the inclination and for the ratio Ra
m/Ra, where Ra is the Rayleigh number due to buoyancy and Ra
m the magnetic Rayleigh number due to the Kelvin magnetic forces. Physically, fundamental modifications of the temperature and velocity profile intervene when Ra
m/Ra >> 1, since, as function of the inclination of the magnetic field, the direction of motion in the infinitely elongated cells can become inverted.
The Major Role of Clinicians in the Discovery of Off‐Label Drug Therapies
Authors: DeMonaco Harold J. , Ali Ayfer , von Hippel Eric
Published: February 2006

Objective. To determine the role of clinicians in the discovery of off‐label use of prescription drugs approved by the United States Food and Drug Administration (FDA).

Data Sources. Micromedex Healthcare Series was used to identify new uses of new molecular entities approved by the FDA in 1998, literature from January 1999–December 2003 was accessed through MEDLINE, and relevant patents were identified through the U.S. Patent and Trademark Office.

Data Synthesis and Main Finding. A survey of new therapeutic uses for new molecular entity drugs approved in 1998 was conducted for the subsequent 5 years of commercial availability. During that period, 143 new applications were identified in a computerized search of the literature for the 29 new drugs considered and approved in 1998. Literature and patent searches were conducted to identify the first report of each new application. Authors of the seminal articles were contacted through an electronic survey to determine whether they were in fact the originators of the new applications. If they were, examination of article content and author surveys were used to explore if each new application was discovered through clinical practice that was independent of pharmaceutical company or university research (field discovery) or if the discovery was made by or with the involvement of pharmaceutical company or university researchers (central discovery). Eighty‐two (57%) of the 143 drug therapy innovations in our sample were discovered by practicing clinicians through field discovery.

Conclusion. To our knowledge, the major role of clinicians in the discovery of new, off‐label drug therapies has not been previously documented or explored. We propose that this finding has important regulatory and health policy implications.
Daptomycin for the Treatment of Gram‐Positive Bacteremia and Infective Endocarditis: A Retrospective Case Series of 31 Patients
Authors: Segreti John A. , Crank Christopher W. , Finney Michael S.
Published: February 2006

Study Objective. To evaluate the outcomes in patients with bacteremia and/or infective endocarditis who were treated with daptomycin.

Design. Retrospective chart review.

Setting. A university‐affiliated medical center in Chicago, Illinois, and a regional hospital in Fountain Valley, California.

Patients. Thirty‐one inpatients treated with daptomycin for bacteremia and/or infective endocarditis.

Measurements and Main Results. Patients were given daptomycin 4–6 mg/kg intravenously every 24–48 hours based on the practitioner's discretion and depending on the patient's clinical condition and presence of comorbidities. Primary end points were resolution of signs and symptoms of infection and discharge from the hospital. Methicillin‐resistant Staphylococcus aureus ([MRSA] 11 patients) and vancomycin‐resistant entercocci ([VRE] 11 patients) were the most common pathogens, whereas 7 patients had methicillin‐sensitive S. aureus infection and 1 patient had coagulase‐negative Staphylococcus infection. One patient with endocarditis had a negative culture result. Overall, 24 (77%) of the 31 patients achieved clinical resolution and were discharged, including all patients infected with MRSA; 7 patients died, 6 of whom had VRE infection. Duration of treatment for infective endocarditis lasted longer (typically 22–43 days) than that for bacteremia only (≤ 14 days), and no patients discontinued daptomycin because of adverse events.

Conclusion. In these patients, daptomycin was safe and well tolerated even for extended durations of treatment. Daptomycin may provide an effective option for treating drug‐resistant gram‐positive bloodstream infections and endocarditis.
Update on Prostate Cancer Chemoprevention
Authors: Lowe Jennifer Fisher , Frazee Lawrence A.
Published: February 2006

Background. Prostate cancer is the most common type of cancer and the second leading cause of cancer‐related deaths in American men. Its high rate of occurrence and long lead time to clinically significant disease make prostate cancer an ideal disease for pharmacologic or nutritional chemoprevention.

Methods. To identify the various chemoprevention strategies for prostate cancer, a MEDLINE search (from 1967–2005) and bibliographic search of the English‐language literature were conducted.

Results. Epidemiologic and retrospective studies have assessed the effect of carotenoids (e.g., lycopene), vitamins, selenium, and nonsteroidal antiinflammatory drugs (NSAIDs) on the rate of occurrence of prostate cancer. The few published prospective trials evaluated prostate cancer as a secondary end point. Lycopene (as β‐carotene) and selenium supplementation have been associated with a reduced risk of prostate cancer in nested case‐control studies, but only in subgroups of men with low baseline plasma lycopene (or β‐carotene) and selenium levels respectively. The Prostate Cancer Prevention Trial prospectively evaluated finasteride, a 5‐α‐reductase inhibitor, as chemoprevention. The results showed a 25% relative risk reduction in prostate cancer, albeit at an increased risk of invasive tumors.

Conclusion. Data regarding lycopene, vitamin E, and selenium as chemoprevention for prostate cancer appear promising. Prospective trials such as the Selenium and Vitamin E Cancer Prevention Trial (SELECT) will clarify the role of these agents in prostate cancer prevention. The role of NSAIDs is unclear, and the long‐term toxicity associated with NSAIDs may limit their usefulness. Although finasteride has decreased overall prostate cancer occurrence, the risk of invasive tumors may outweigh the benefit of this agent. The continuing Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial may help define a role for the 5‐α‐reductase inhibitors in cancer chemoprevention. At this time, nothing has been proven effective as chemoprevention against clinically significant prostate cancer.
Salicylate Toxicity Associated with Administration of Percy Medicine in an Infant
Authors: Lewis Teresa V. , Badillo Randal , Schaeffer Scott , Hagemann Tracy M. , McGoodwin Lee
Published: February 2006

Percy Medicine is a nonprescription gastrointestinal suspension containing bismuth subsalicylate as the active ingredient (1050 mg/10‐ml dose). A 3‐month‐old infant with colic developed salicylate toxicity requiring hospitalization in the pediatric intensive care unit (PICU) as a result of continued administration of this medicine. Bismuth subsalicylate has an aspirin equivalency conversion factor of 0.479 (approximately half the strength of aspirin). For 3.5 weeks the infant's parents administered the medicine, which provided the equivalent of aspirin 57–84 mg/kg/day with no reported problems. However, on the day of admission the baby presented with central nervous system depression and respiratory distress. Assessment at a local emergency facility revealed metabolic acidosis; his serum salicylate concentration was 747 mg/L. After acute management, the patient was transferred to our hospital, where he was treated with whole bowel irrigation and alkalinization therapy. Subsequently, the baby required 4 days of management in the PICU and 2 additional days of observation in a general nursing unit before he was discharged home without incident. The parents had chosen Percy Medicine based on the picture of a baby on the front of the package and because of its placement on the shelf next to a drug their family physician had recommended previously. Salicylate‐containing products are not routinely recommended for children aged 1 year or younger. The general public may assume that over‐the‐counter products are safe because they do not require a prescription. Health care professionals must be responsible for educating the public regarding risks associated with over‐the‐counter products and the need to read and follow label directions.
A Case of Simvastatin‐Associated Pancreatitis and Review of Statin‐Associated Pancreatitis
Authors: Johnson Jeremy L. , Loomis Ilana B.
Published: February 2006

Reduction of low‐density lipoprotein cholesterol (LDL) concentration has become the primary goal and a standard of care in the practice of cholesterol management. The 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase inhibitors, or statins, are the most frequently prescribed lipid‐lowering agents on the market. As more information is learned through the results of clinical trials, LDL goals become more stringent and difficult to attain. Large doses of high‐potency statins, sometimes given in combination with other lipid‐lowering agents, are frequently necessary to achieve these goals. As a result, the frequency of adverse effects from statin therapy may be expected to increase, and less common adverse effects may occur more often. As statins are used more aggressively, rare and possibly dangerous adverse effects must be identified, especially those that are becoming more frequently encountered. Increased awareness may lead to earlier diagnosis and management of diseases that may be caused by the statins. We describe a 58‐year‐old man who was hospitalized with idiopathic pancreatitis 4 months after starting simvastatin therapy. His oral drug therapy was withheld, and he was treated with bowel rest. The patient was discharged on hospital day 5, and his oral drug regimen, including simvastatin, was resumed. He was admitted again 16 months later with a second diagnosis of acute pancreatitis and was discharged after 3 days of bowel rest with no oral drug therapy. Simvastatin was restarted on discharge, but the patient stopped taking it after experiencing muscle soreness and weakness in his arms. He recalled having similar arm pain that preceded the previous episode of acute pancreatitis. All other causes of the pancreatitis had been ruled out; thus, the correlation between simvastatin‐induced myalgia and onset of acute pancreatitis on two separate occasions made simvastatin the suspected instigating agent. Pancreatitis is a rare adverse effect of statin therapy, but it has been documented in several case reports involving most of the statins. Continued reporting is necessary to increase awareness of this rare adverse effect of simvastatin so that it may be promptly managed or avoided in the future.
Treatment of Heparin‐Induced Thrombocytopenia with Drotrecogin Alfa (activated)
Authors: Rubeiz George J. , Marrone Christopher M. , Leclerc Jacques R.
Published: February 2006

A patient was administered drotrecogin alfa (activated) in addition to the standard of care for presumed severe sepsis and circulatory shock. Heparin‐induced thrombocytopenia (HIT) and hepatic and splenic thromboses complicated her clinical course. Because drotrecogin alfa (activated) treatment is associated with improvement in thrombotic manifestations and thrombocytopenia, it was continued as the sole antithrombotic agent after the HIT became apparent. This approach was chosen despite the patient's severe hepatic and renal dysfunction, which made the use of direct thrombin inhibitors unfavorable. She survived with a reasonable outcome and salvage of her limbs. Although this case suggests a potential role of drotrecogin alfa (activated) in the management of HIT, systematic evaluation of its efficacy in this situation is warranted.
Dipyrone‐Induced Granulocytopenia: A Case for Awareness
Authors: Garcia Santiago , Canionero Mariana , Lopes Gilberto
Published: February 2006

Dipyrone, also known as metamizole, is an analgesic and antipyretic drug that was banned by the United States Food and Drug Administration because of its association with agranulocytosis. However, it is still produced and marketed in several countries in Central and South America as well as in Europe, Asia, and Africa. It can also be found in the United States, where illegal sales have been reported in California gift shops, markets, bakeries, and other retail establishments. Dipyrone is commonly found in the homes of families who are originally from areas where it is still lawfully marketed. We describe a patient who developed granulocytopenia and fever after taking dipyrone and discuss the available literature. Our aim is to raise awareness of this drug, which is commonly used outside the United States, and to call attention to its well‐known and potentially lethal side effect.
A two‐dimensional model for simulation, control, and optimization of FCC risers
Authors: Souza J. A. , Vargas J. V. C. , Von Meien O. F. , Martignoni W. , Amico S. C.
Published: February 2006

A simplified two‐dimensional (2‐D) formulation for FCC risers has been developed. The model approximates the mixture of gasoil, steam, and solid catalyst that flows inside the riser reactor by an equivalent fluid with average properties. The cracking reactions are modeled by a 6‐lump kinetic model combined with two energy equations (gas and solid). Due to the adopted simplifications, a fast and simple‐to‐solve computational code was written; nevertheless, it still is sufficiently precise to be used for the design of new units and for system control and optimization of operating conditions of FCC risers. The validation of the proposed model was performed by direct comparison of the obtained results with available experimental data for a multi‐purpose pilot FCC riser unit. The model was then utilized to simulate an actual size industrial FCC riser. The obtained numerical results in this article demonstrate that the model can be used as a powerful and simple tool for design, control, and optimization of FCC units, combining accuracy with low computational time to obtain solutions when simulating actual FCC riser operation. © 2006 American Institute of Chemical Engineers AIChE J, 2006
A longitudinal functional magnetic resonance imaging study of language development in children 5 to 11 years old
Authors: Szaflarski Jerzy P. , Schmithorst Vincent J. , Altaye Mekibib , Byars Anna W. , Ret Jennifer , Plante Elena , Holland Scott K.
Published: February 2006

Objective

Language skills continue to develop rapidly in children during the school‐age years, and the “snapshot” view of the neural substrates of language provided by current neuroimaging studies cannot capture the dynamic changes associated with brain development. The aim of this study was to conduct a 5‐year longitudinal investigation of language development using functional magnetic resonance imaging in healthy children.

Methods

Thirty subjects enrolled at ages 5, 6, or 7 were examined annually for 5 years using a 3‐Tesla magnetic resonance imaging scanner and a verb generation task. Data analysis was conducted based on a general linear model that was modified to investigate developmental changes whereas minimizing the potential for missing data.

Results

With increasing age, there is progressive participation in language processing by the inferior/middle frontal, middle temporal, and angular gyri of the left hemisphere and the lingual and inferior temporal gyri of the right hemisphere and regression of participation of the left posterior insula/extrastriate cortex, left superior frontal and right anterior cingulate gyri, and left thalamus.

Conclusion

The age‐related changes observed in this study provide evidence of increased neuroplasticity of language in this age group and may have implications for further investigations of normal and aberrant language development. Ann Neurol 2006
Chemistry of copper trimercaptotriazine (TMT) compounds and removal of copper from copper‐ammine species by TMT
Authors: Dongmei Liao , Yunbai Luo , Ping Yu , Zhigang Chen
Published: February 2006

The acid dissociation constants of 2,4,6‐trimercaptotriazine (H3TMT) were determined by acid‐base titration and now can be employed in the preparation of complexes having specific Cu–TMT ratios. IR, EA and TGA characterized the compounds. We analyzed the relevant IR spectra and attribute 2910–2925, 3030–3250 and 3430 cm−1 to triazine ring overtone, NH stretching vibrations and water in the TMT complexes, respectively. The solubility of Cu–TMT complexes was determined with ICP‐AES. The results indicate that Cu3 (TMT)2 · 2H2O (3) is much more insoluble and more stable than Cu (H2TMT)2 (1), Cu (HTMT)·0.5H2O (2) and CuS. The extremely small value of KSP for compound 3 (2.11 × 10−46) indicates that Na3TMT is a very advantageous chelating agent in precipitating complex copper (e.g. copper‐ammine species) from industrial wastewaters. The influences of ammonia concentration, pH and settling time on the effectiveness of copper precipitation were investigated. Also, a ‘real world’ printed circuit board factory effluent initially containing 350.9 ppm of Cu was treated and it was found that more than 99.9% of the copper was removed from the solution as an insoluble compound 3. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of ultrasound on the viscoelasticity and rheology of polystyrene extruded through a slit die
Authors: Chen Yingzi , Li Huilin
Published: February 2006

The rheological and processing behavior (melt fracture performance) of polystyrene extruded through a slit die is studied as a function of the ultrasound vibration intensity. The apparent viscosity reduces 29% and die pressure reduces 22% compared with that without ultrasound vibration. The viscosity of the melt decreases exponentially as ultrasound intensity increases and an Arrhenius equation fits the data well. Ultrasound vibration also leads to a decrease of the die swell ratio and a postponement of melts fracture. Characteristic relaxation times at the onset of melt fracture are calculated according to the hypothesis that the melt fracture behavior of a polymer is affected by a balance between its viscous (viscosity) and elastic properties (recoverable shear). Ultrasound vibration shortens the relaxation time of polystyrene molecular chains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2907–2911, 2006