bluuebunny/crossref_metadata_2025 huggingface dataset:
Affinity monolithic capillary columns for glycomics/proteomics: 1. Polymethacrylate monoliths with immobilized lectins for glycoprotein separation by affinity capillary electrochromatography and affinity nano‐liquid chromatography in either a single column or columns coupled in series
Authors: Okanda Fred M. , El Rassi Ziad
Published: February 2006

In this report, microcolumn separation schemes involving monolithic capillary columns with immobilized lectins, and relevant to nanoglycomics/nanoproteomics were introduced. Positive and neutral monoliths based on poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) were designed for achieving lectin affinity chromatography (LAC) by nano‐LC and CEC. The positive monoliths (i.e., monoliths with cationic sites) afforded relatively high permeability in nano‐LC but lack predictable EOF magnitude and direction, while neutral monoliths provided a good compromise between reasonable permeability in nano‐LC and predictable EOF in CEC. Lectin affinity nano‐LC permitted the enrichment of classes of different glycoproteins having similar N‐glycans recognized by the immobilized lectin, whereas lectin affinity CEC provided the simultaneous capturing and separation of different glycoproteins due to differences in charge‐to‐mass ratio. Also, this investigation demonstrated for the first time the coupling of lectin capillary columns in series (i.e., tandem columns) for enhanced separation of glycoproteins by LAC using the CEC modality. Furthermore, in the coupled columns format, glycoforms of a given glycoprotein were readily separated.
Gully erosion in the Siwalik Hills, Nepal: estimation of sediment production from active ephemeral gullies
Authors: Ghimire Sohan K. , Higaki Daisuke , Bhattarai Tara P.
Published: February 2006

A simple field‐based monitoring programme was established in a small catchment (area 4·6 km2) to find the rates of gully erosion in the Siwalik Hills, Nepal. The rates are used to estimate the amount of sediment produced by gully erosion in the catchment. Three large and active gullies were selected with areas ranging from 0·44 to 0·78 ha. Aerial photographs taken in 1964, 1978 and 1992 were ortho‐rectified and used to study the dynamics of gully heads. The same gullies were also monitored manually using an orthogonal reference system fixed by erosion pins around the gully heads. Results from the aerial photos indicated that the gullies expanded remarkably over the period from 1964 to 1992, by 34 to 58 per cent. Head‐retreat rates during that period were 0·48, 0·55 and 0·73 m a−1 and average annual sediment evacuation was estimated as 2534 ± 171, 959 ± 60 and 2783 ± 118 m3 a−1 for the three gullies respectively. From the field measurement, estimated volumes were found to vary from 731 ± 57 to 2793 ± 201 m3 a−1 over the monitoring period of two years. It was also found that the gullies produce sediment which accounts for up to 59 per cent of the sediment produced from surface erosion in the headwater catchment. The findings are useful for planning and executing appropriate control measures and constructing a sediment hazard map at the catchment scale. Copyright © 2006 John Wiley & Sons, Ltd.
Stereophotogrammetry of archive data and topographic approaches to debris‐flow torrent measurements: calculation of channel‐sediment states and a partial sediment budget for Manival torrent (Isère, France)
Authors: Veyrat‐Charvillon S. , Memier M.
Published: February 2006

This paper focuses on a topographic methodology to characterize the amount of sediment stored in channels and the use of historical photographs for aerial survey by stereophotogrammetry, as part of wider research on debris‐flow magnitude prediction. The topographic methodology uses equidistant four‐point cross‐sections along the long profile of the channel. Each cross‐section is representative of a 50‐m reach of the channel. To calculate the volume of each reach, the difference is calculated between a reference level and the topographic surface. The reference level is the lowest level where the debris flow can erode, and in the current method this level is estimated from fixed points along the long profile of the channel. The accuracy of the method has been estimated by comparing results of a detailed topographic survey, with a standard deviation corresponding to about 6 per cent of the total calculated sediment volume.

This topographic methodology has been used on aerial photographs by photogrammetry. This tool was applied to photographs taken on 12 past dates. The scales of the archive photographs used range from 1:3000 to 1:30 000, but results are consistent and permit us to calculate sediment states of the channel for different past dates with an uncertainty of about 6 per cent of the total volume. The application of the technique to the Manival debris‐flow torrent has permitted us to propose some partial sediment budgets and erosion‐rate estimates. Copyright © 2006 John Wiley & Sons, Ltd.
LES of the compressed Taylor vortex flow using a finite volume/finite element method on unstructured grids
Authors: Le Ribault C. , Le Penven L. , Buffat M.
Published: February 2006

Large‐eddy simulations (LES) have been performed of a compressed vortex flow undergoing transition to turbulence. The numerical method is based on a finite volume/finite element discretization of the compressible Navier–Stokes equations on unstructured grids and a Roe second‐order scheme with MUSCL extrapolation. A particular attention is paid to the dissipative character of the method, controlled by a coefficient related to the upwind part of the numerical scheme, and its interference with the subgrid model. The accuracy of the method is first checked in the case of decaying homogeneous isotropic turbulence. The investigation is then directed to a plane Taylor vortex flow submitted to compression, in a direction perpendicular to the vorticity vector. This flow is unstable with respect to three‐dimensional perturbations and transition to turbulence is observed if the Reynolds number is large enough. The numerical method is used to simulate this vortex flow for two values of the Reynolds number. For the lower value, the flow is unstable but remains laminar and no subgrid model is used. For the higher one, the turbulence appears and the standard and the dynamic Smagorinsky models are tested. The LES results are compared to those obtained by direct numerical simulations (DNS) using a spectral Fourier method. Copyright © 2006 John Wiley & Sons, Ltd.
Sensitivity computations of eddy viscosity models with an application in drag computation
Authors: Pahlevani Faranak
Published: February 2006

This paper presents a numerical study of the sensitivity of an eddy viscosity model with respect to the variation of the eddy viscosity parameter for the two‐dimensional driven cavity problem and flow around a cylinder. The main objective is to provide a comparison between computing the sensitivity using sensitivity equation and computing the sensitivity using finite difference methods and also numerically illustrate the application of the sensitivity computations in improving drag flow functional. Copyright © 2006 John Wiley & Sons, Ltd.
Adaptive mesh refinement techniques for high‐order shock capturing schemes for multi‐dimensional hydrodynamic simulations
Authors: Baeza Antonio , Mulet Pep
Published: February 2006

The numerical simulation of physical phenomena represented by non‐linear hyperbolic systems of conservation laws presents specific difficulties mainly due to the presence of discontinuities in the solution. State of the art methods for the solution of such equations involve high resolution shock capturing schemes, which are able to produce sharp profiles at the discontinuities and high accuracy in smooth regions, together with some kind of grid adaption, which reduces the computational cost by using finer grids near the discontinuities and coarser grids in smooth regions. The combination of both techniques presents intrinsic numerical and programming difficulties. In this work we present a method obtained by the combination of a high‐order shock capturing scheme, built from Shu–Osher's conservative formulation (J. Comput. Phys. 1988; 77:439–471; 1989; 83:32–78), a fifth‐order weighted essentially non‐oscillatory (WENO) interpolatory technique (J. Comput. Phys. 1996; 126:202–228) and Donat–Marquina's flux‐splitting method (J. Comput. Phys. 1996; 125:42–58), with the adaptive mesh refinement (AMR) technique of Berger and collaborators (Adaptive mesh refinement for hyperbolic partial differential equations. Ph.D. Thesis, Computer Science Department, Stanford University, 1982; J. Comput. Phys. 1989; 82:64–84; 1984; 53:484–512). Copyright © 2006 John Wiley & Sons, Ltd.
Volumetric methods for evaluating irreversible energy losses and entropy production with application to bioengineering flows
Authors: Moyle Keri , Mallinson Gordon , Cowan Brett
Published: February 2006

Methods for calculating irreversible energy losses and rates of heat transfer from computational fluid dynamics solutions using volume integrations of energy dissipation functions contrast with the more usual approach of performing first law energy balances over the boundaries of a flow domain. Advantages of the approach are that the estimates involve the whole flow domain, and are hence based on more information than would otherwise be used, and that the energy dissipation function allows for detailed assessment of the mechanisms and regions of energy loss.

The research was motivated by a need to clarify energy losses by haemodynamics in the greater vessels of the human body, in particular, the Fontan connection. For this application irreversible energy losses were calculated using the viscous dissipation function. Streamwise integration of the viscous dissipation function is also used to explore the ways in which different flow structures contribute to energy losses. Copyright © 2006 John Wiley & Sons, Ltd.
Course and outcome of hepatitis C
Authors: Hoofnagle Jay H.
Published: February 2006

The hepatitis C virus (HCV) is a small enveloped RNA virus belonging to the family flaviviridae and genus hepacivirus. The HCV RNA genome is 9,600 nucleotides in length and encodes a single polyprotein that is post-translationally cleaved into 10 polypeptides including t3 structural (C, E1, and E2) and multiple nonstructural proteins ([NS] NS2 to NS5). The NS proteins include enzymes necessary for protein processing (proteases) and viral replication (RNA polymerase). The virus replicates at a high rate in the liver and has marked sequence heterogeneity. There are 6 genotypes and more than 90 subtypes of HCV, the most common in the United States being 1a and 1b (approximately 75%), 2a and 2b (approximately 15%), and 3 (approximately 7%). Acute hepatitis C is marked by appearance of HCV RNA in serum within 1 to 2 weeks of exposure followed by serum alanine aminotransferase (ALT) elevations, and then symptoms and jaundice. Antibody to HCV (anti-HCV) tends to arise late. In acute resolving hepatitis, HCV RNA is cleared and serum ALT levels fall to normal. However, 55% to 85% of patients do not clear virus, but develop chronic hepatitis C. Chronic hepatitis C is often asymptomatic, but is usually associated with persistent or fluctuating elevations in ALT levels. The chronic sequelae of hepatitis C include progressive hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. Extra-hepatic manifestations include sicca syndrome, cryoglobulinemia, glomerulonephritis, and porphyria cutanea tarda. Knowledge of the course and outcome of hepatitis C is important in developing approaches to management and therapy. (Hepatology 2002;36:S21-S29).
Natural history of chronic hepatitis C
Authors: Seeff Leonard B.
Published: February 2006

Much controversy surrounds the issue of the natural history of hepatitis C virus (HCV) infection. Many authorities view the disease as inexorably progressive with a high probability of advancing over time to cirrhosis and occasionally hepatocellular carcinoma (HCC) and, therefore, likely to be responsible for causing death. Others regard chronic hepatitis C as having a variable outcome, the majority of infected persons not dying from the disease, but more likely from the comorbid conditions that so often accompany infection by this agent, or from more common medical conditions. Disagreements probably derive from the manner of conduct of the study and the populations studied. Efforts to determine natural history are handicapped by the primary characteristics of the disease, namely that its onset rarely is recognized and its course is prolonged exceedingly. Thus, different outcomes have come from retrospective rather than from prospective studies, but both have concluded that at least 20% of chronically infected adults develop cirrhosis within 20 years. More recent studies that used a retrospective/prospective approach, focusing largely on young infected individuals, have produced different results. Among these young people, particularly young women, spontaneous resolution of the viral infection is more common than previously thought and cirrhosis has been identified in 5% or fewer of them. The major failing for all groups studied, young and old, is that natural history studies have rarely exceeded the first 2 decades, so that outcome beyond this time is not known, other than through modeling. Several host-related and extraneous factors probably affect the natural history. (Hepatology 2002;36:S35-S46).
Maternal-infant transmission of hepatitis C virus infection
Authors: Roberts Eve A. , Yeung Latifa
Published: February 2006

Mother-to-infant transmission of hepatitis C virus (HCV) is comparatively uncommon. The prevalence of antibody to HCV (anti-HCV) in pregnant women is 0.1% to 2.4%, although in some endemic areas it is much higher. The proportion of women with anti-HCV who have active infection with viremia is 60% to 70%. Transmission of HCV occurs only when serum HCV RNA is detectable and may be related to higher levels (above 106 copies per mL). The rate of mother-to-infant transmission is 4% to 7% per pregnancy in women with HCV viremia. Co-infection with human immunodeficiency virus (HIV) increases the rate of transmission 4 to 5 fold. The actual time and mode of transmission are not known. Elective Cesarean section is not recommended for women with chronic HCV infection alone. The role of treatment to prevent transmission is limited by the fetal toxicity of currently available medications for hepatitis C. Breast feeding poses no important risk of HCV transmission if nipples are not traumatized and maternal hepatitis C is quiescent. Pregnant women at high risk for HCV infection should be screened for anti-HCV, and HCV RNA testing should be performed if anti-HCV is positive. Infants of women with hepatitis C should be tested for HCV RNA on two occasions, between the ages of 2 and 6 months and again at 18 to 24 months, along with serum anti-HCV. The natural history of mother-to-infant hepatitis C remains uncertain, especially the course in the first year of life when some infants appear to have spontaneous resolution. (Hepatology 2002;36:S106-S113).
Optimal therapy of hepatitis C
Authors: Di Bisceglie Adrian M. , Hoofnagle Jay H.
Published: February 2006

The highest response rates to antiviral therapy for the treatment of chronic hepatitis C have been achieved using the combination of peginterferon and ribavirin. Recently completed controlled trials have reported rates of sustained virological response (SVR) between 50% and 60% in patients treated with higher doses of peginterferon and ribavirin, which was 5% to 1O% higher with standard doses of interferon alfa and ribavirin. The major determinant of outcome of therapy is hepatitis C virus (HCV) genotype. With the combination of peginterferon and ribavirin, patients with genotype 1 achieve response rates of 40% to 45%, compared with rates approaching 80% with genotypes 2 or 3. Importantly, patients with HCV genotype 1 achieve higher rates of response with 48 weeks than with 24 weeks of therapy, whereas patients with genotypes 2 and 3 are adequately treated with a 24-week course. Furthermore, patients with genotypes 2 and 3 require only 800 mg of ribavirin daily to achieve optimal response rates, whereas 1,000 to 1,200 mg daily is needed for patients with genotype 1. Future studies should focus on optimizing the dose of peginterferon and ribavirin by patient characteristics, particularly on resolving the issue of weight-based dosing. For patients with good prognostic factors, a lower dose and shorter course of peginterferon may be adequate for full effect. Importantly, research is needed to show how treatment regimens can best be applied to other patient groups with hepatitis C, such as patients with acute hepatitis, human immunodeficiency virus coinfection, renal disease, solid-organ transplant, neuropyschiatric disease, autoimmunity, and alcohol or substance abuse. (Hepatology 2002;36:S121-S127).
Treatment of chronic hepatitis C: A systematic review
Authors: Chander Geetanjali , Sulkowski Mark S. , Jenckes Mollie W. , Torbenson Michael S. , Herlong Franklin H. , Bass Eric B. , Gebo Kelly A.
Published: February 2006

This systematic review addressed 3 issues regarding current treatments for chronic hepatitis C: (1) efficacy and safety in treatment-naive patients; (2) efficacy and safety in selected subgroups of patients; and (3) effects on long-term clinical outcomes. Electronic databases were searched for articles from January 1996 to March 2002. Additional articles were identified by searching references in pertinent articles and recent journals and by questioning experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, or clinical outcome measures. For data collection, paired reviewers assessed the quality of each study and abstracted data. This systematic review found that the combination of high-dose peginterferon and ribavirin was more efficacious than standard interferon and ribavirin in persons infected with hepatitis C virus (HCV) genotype 1 (sustained virologic response [SVR] rate: 42% vs. 33%) and that ranges of SVR rates were higher with peginterferon than standard interferon monotherapy in naíve patients (10% to 39% vs. 3% to 19%). Reports were consistent in showing treatment with interferon and ribavirin was more efficacious than interferon monotherapy in treatmentnaive persons and previous nonresponders and relapsers. Studies were moderately consistent in showing that treatment decreases the risk for hepatocellular carcinoma (HCC). The evidence on treatment in important subgroups was limited by a lack of randomized controlled trials. Thus, the combination of peginterferon and ribavirin was the most efficacious treatment in patients with HCV genotype 1. Long-term outcomes were improved in patients with hepatitis C who achieved an SVR with treatment.
Therapy of acute hepatitis C
Authors: Alberti Alfredo , Boccato Silvia , Vario Alessandro , Benvegnù Luisa
Published: February 2006

Acute hepatitis C has a high propensity to become chronic, which provides the rationale for treating patients with acute disease attempting to prevent chronicity. Almost all published studies on therapy of acute hepatitis C have been small in size, uncontrolled, and highly heterogeneous as to patient features, dose and duration of treatment, follow-up evaluation, and criteria used to define efficacy and safety. The published studies on treatment of acute hepatitis C have used standard alfa or beta interferon monotherapy: none have evaluated combination therapy of interferon and ribavirin or peginterferon. Several meta-analyses of published studies have concluded that initiation of interferon monotherapy during the acute phase of hepatitis C virus (HCV) infection significantly reduces (by 30% to 40%) evolution to chronic hepatitis. The tolerability of interferon in acute hepatitis C has been excellent, even in symptomatic and icteric patients; the side effects and adverse events being similar in type and frequency to those seen when treating chronic cases. Thus, currently available data support treatment of patients with acute hepatitis C, but data are insufficient to draw firm conclusions about which patients to treat, when therapy should be started, or what regimen is optimal. Future studies of adequate size and design should focus on efficacy and tolerability of peginterferons and whether therapy should be started immediately after diagnosis or delayed for 2 to 4 months to avoid treatment of patients who spontaneously recover. (Hepatology 2002;36:S195-S200).
Hepatitis C and human immunodeficiency virus infection
Authors: Thomas David L.
Published: February 2006

In the United States, an estimated 200,000 persons are infected with both hepatitis C virus (HCV) and human immunodeficiency virus (HIV). As the lives of HIV-infected persons have been prolonged by use of highly active antiretroviral therapy, liver disease has emerged as an important, and in some settings, the leading cause of morbidity and mortality. Human immunodeficiency virus infection appears to adversely affect all stages of hepatitis C infection, leading to increased viral persistence and accelerated progression of HCV-related liver disease. In turn, hepatitis C may affect the management of HIV infection, increasing the incidence of liver toxicity caused by antiretroviral medications. The medical management of hepatitis C in HIV-infected persons remains controversial, in part because of the complexity of both infections and potential drug interactions, but chiefly because there is so little published information. Nonetheless, the burden of liver disease is too high to delay management of HIV/HCV-coinfected persons while awaiting better data. Instead, the management of hepatitis C today must be based on data generated on persons without HIV and an understanding of both infections. Properly designed studies of therapy in HIV/HCV-coinfected persons are needed to help guide management of these patients in the future. (Hepatology 2002;36:S201-S209).
Prevention and treatment of hepatitis C in injection drug users
Authors: Edlin Brian R.
Published: February 2006

Injection drug users constitute the largest group of persons infected with the hepatitis C virus (HCV) in the United States, and most new infections occur in drug users. Controlling hepatitis C in the U.S. population, therefore, will require developing, testing, and implementing effective prevention and treatment strategies for persons who inject drugs. Fortunately, a substantial body of research and clinical experience exists on the prevention and management of chronic viral diseases among injection drug users. The need to implement interventions to stop the spread of HCV among drug users is critical. The capacity of substance-use treatment programs need to be expanded to accommodate all who want and need treatment. Physicians and pharmacists should be educated in how to provide access to sterile syringes and to teach safe injection techniques, both of which are lifesaving interventions. The treatment of hepatitis C in drug users requires an interdisciplinary approach that brings together expertise in treating hepatitis and caring for drug users. Treatment decisions should be made individually by patients with their physicians, based on a balanced assessment of risks and benefits and the patient’s personal values. Physicians should carefully assess, monitor, and support adherence and mental health in all patients, regardless of whether drug use is known or suspected. Research is needed to better understand how best to prevent and treat hepatitis C in substance users. In the meantime, substantial progress can be made if existing knowledge and resources are brought to bear. (Hepatology 2002;36:S210-S219).
Side effects of therapy of hepatitis C and their management
Authors: Fried Michael W.
Published: February 2006

Interferon and ribavirin combination therapy for chronic hepatitis C produces a number of well-described side effects that are dominated by fatigue, influenza-like symptoms, hematologic abnormalities, and neuropsychiatric symptoms. Combination therapy with pegylated interferons (peginterferon alfa-2a and alfa-2b) yields an adverse event profile similar to standard interferon, although the frequency of certain adverse events may vary by preparation. Premature withdrawal from therapy due to adverse events was required in 10% to 14% of participants in registration trials of these agents. Most adverse events were safely and effectively managed by dose reduction using predetermined criteria. The most common indications for dose reduction were hematologic abnormalities, such as anemia and neutropenia, with the latter more frequent in peginterferon treatment arms. Recent data suggest that maintaining adherence to a prescribed treatment regimen can enhance antiviral response. Strategies to maximize adherence are being developed and, in the future, may include early identification of and therapy for depression and the selective use of hematopoietic growth factors to ameliorate hematologic abnormalities.
Future therapy of hepatitis C
Authors: McHutchison John G. , Patel Keyur
Published: February 2006

Currently available therapies for the treatment of chronic hepatitis C are effective in half of patients, but are expensive, often poorly tolerated, and unsuitable for certain patients populations. The ideal therapy would be highly effective, orally bioavailable, have minimal side effects, be cost effective, and suitable for the majority of patients with hepatitis C. Recent advances in understanding the replication cycle of hepatitis C virus (HCV) and structural, crystallographic definitions of components of the viral polyprotein have improved the prospects for development of novel therapies. The lack of a small animal model of HCV infection continues to hamper progress in the preclinical evaluation of new antivirals and vaccines. Strategies to enhance response to current therapies include the development of novel interferons and delivery systems, nucleoside analogues that have reduced hemolysis compared with ribavirin, inosine 5′ monophosphate dehydrogenase inhibitors, and other immunomodulators that are being evaluated as adjunctive therapy to interferon-based regimens. Compounds in preclinical or early phase human trials include small molecules that inhibit virus specific enzymes (such as the serine proteases, RNA polymerase and helicase), or those that prevent translation initiation (such as antisense molecules and ribozymes). Antifibrotic agents are also being developed in an attempt to prevent disease progression in patients in whom HCV RNA cannot be eradicated. While the advent of these newer compounds represent an exciting phase in the treatment of HCV, their safety and efficacy need to be established. Most of these newer therapies are unlikely to be available for routine clinical use in the next 3 to 5 years. (Hepatology 2002;36:S245-S242).
Secretion of tartrate‐resistant acid phosphatase by osteoclasts correlates with resorptive behavior
Authors: Kirstein Barrie , Chambers Timothy J. , Fuller Karen
Published: February 2006

There have been dramatic advances recently in our understanding of the regulation of osteoclastic differentiation. However, much less is known of the mechanisms responsible for the induction and modulation of resorptive behavior. We have developed a strategy whereby osteoclasts can be generated in vitro and released into suspension in a fully‐functional state. We now exploit this approach to show that tartrate‐resistant acid phosphatase (TRAP) is released by osteoclasts during bone resorption. TRAP release was inhibited by the secretion‐inhibitor Brefeldin A, and was not accompanied by LDH release. This suggests that TRAP release is due to secretion, rather than cell death. Consistent with this, TRAP secretion was stimulated by resorbogenic cytokines, was inhibited by the resorption‐inhibitor calcitonin, and correlated with excavation of the bone surface. We found that, in contrast to incubation on bone, incubation on plastic, glass, or vitronectin‐coated plastic substrates did not induce secretion of TRAP. This suggests that the induction of resorptive behavior in osteoclasts depends upon stimulation by bone matrix of a putative osteoclastic “mineral receptor.” Release of TRAP by osteoclasts thus represents not only a productive approach to the analysis of the mechanisms that modulate the rate of resorptive activity, but also a system whereby the mechanism through which bone substrates induce resorptive behavior can be identified. J. Cell. Biochem. 98: 1085–1094, 2006. © 2006 Wiley‐Liss, Inc.
Synthesis of d3‐cerivastatin for use as internal standard in a LC/MS/MS method developed for quantitation of the drug in human serum
Authors: Chen Bang‐Chi , Bednarz Mark S. , Zhang Huiping , Guo Peng , Jemal Mohammed , Robl Jeffrey A. , Biller Scott A. , Sundeen Joseph E. , Balasubramanian Balu , Barrish Joel C.
Published: February 2006

d3‐Cerivastatin was synthesized as an internal standard for use in a LC/MS/MS method developed for the simultaneous quantitative determination of the drug in human serum. d3‐Cerivastatin was efficiently prepared on large scale from d3‐iodomethane using improved procedures. Copyright © 2006 John Wiley & Sons, Ltd.
MR angiography fusion technique for treatment planning of intracranial arteriovenous malformations
Authors: McGee Kiaran P. , Ivanovic Vladimir , Felmlee Joel P. , Meyer Fredrick B. , Pollock Bruce E. , Huston John
Published: February 2006

Purpose

To develop an image fusion technique using elliptical centric contrast‐enhanced (CE) MR angiography (MRA) and three‐dimensional (3D) time‐of‐flight (TOF) acquisitions for radiosurgery treatment planning of arteriovenous malformations (AVMs).

Materials and Methods

CE and 3D‐TOF MR angiograms with disparate in‐plane fields of view (FOVs) were acquired, followed by k‐space reformatting to provide equal voxel dimensions. Spatial domain addition was performed to provide a third, fused data volume. Spatial distortion was evaluated on an MRA phantom and provided slice‐dependent and global distortion along the three physical dimensions of the MR scanner. In vivo validation was performed on 10 patients with intracranial AVMs prior to their conventional angiogram on the day of gamma knife radiosurgery.

Results

Spatial distortion in the phantom within a volume of 14 × 14 × 3.2 cm3 was less than ±1 mm (±1 standard deviation (SD)) for CE and 3D‐TOF data sets. Fused data volumes were successfully generated for all 10 patients.

Conclusion

Image fusion can be used to obtain high‐resolution CE‐MRA images of intracranial AVMs while keeping the fiducial markers needed for gamma knife radiosurgery planning. The spatial fidelity of these data is within the tolerance acceptable for daily quality control (QC) purposes and gamma knife treatment planning. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Photodynamic therapy with topical 5‐aminolevulinic acid as a post‐operative adjuvant therapy for an incompletely resected primary nasopharyngeal papillary adenocarcinoma: A case report
Authors: Wang Cheng‐Ping , Chang Yih‐Leong , Chen Chin‐Tin , Yang Ting‐Hua , Lou Pei‐Jen
Published: February 2006

Background and Objectives

Surgical excision of primary nasopharyngeal papillary adenocarcinoma is sometimes incomplete with remaining microscopic disease. Post‐operative radiotherapy only has limited efficacy but may cause many complications.

Study Design/Materials and Methods

Photodynamic therapy (PDT) was used as a post‐operative adjuvant therapy for an incompletely resected primary nasopharyngeal papillary adenocarcinoma. A special form of 20% topical 5‐aminolevulinic acid (5‐ALA), which was originally a liquid form and became a gel form after applied on the nasopharynx, was used as the photosensitizer. A 2‐mm optic fiber delivered the light (633 nm wavelength) to the lesion with a fluence rate of 100 mW/cm2 generated by a diode laser under 5 mm 0° endoscope assistance. The total energy delivered was 150 joules/cm2.

Results

No significant acute side effect was noted and the nasopharyngeal wound healed rapidly. The patient is alive without locoregional recurrence or distant metastasis for 5 years. Articulation, salivation, and swallowing functions are all well preserved.

Conclusion

Post‐operative adjuvant PDT can successfully cure an otherwise difficult to treat disease with preservation of good life quality of the patient. Potential complications of PDT (e.g., photosensitivity) can be prevented by a special formulation of topical 5‐ALA preparation. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Cover Picture: Macromol. Mater. Eng. 2/2006
Authors: Sánchez‐Valdes Saúl , López‐Quintanilla Maria L. , Ramírez‐Vargas Eduardo , Medellín‐Rodríguez Francisco J. , Gutierrez‐Rodriguez Juan M.
Published: February 2006

Cover: The picture on the cover shows the XRD patterns of polyethylene/clay nanocomposites using maleic anhydride and ionomer as compatibilizers after the first and second step of mixing through the extruder. It also shows TEM images of the clay dispersion in the samples with no compatibilizer and when using maleic anhydride and ionomer as compatibilizers. Further details can be found in the article by S. Sánchez‐Valdes,* M. L. López‐Quintanilla, E. Ramírez‐Vargas, F. J. Medellín‐Rodríguez, and J. M. Gutierrez‐Rodriguez on page 128.
Cover Picture: Macromol. Theory Simul. 2/2006
Authors: O'Brien Allison K. , Bowman Christopher N.
Published: February 2006

Cover: The illustration on the cover presents model results for the strong inhibitory effects of oxygen on the photopolymerization reaction. Oxygen inhibition and diffusion of oxygen back into the sample from the atmosphere lead to the formation of an unpolymerized layer at the top surface of the film. Further details can be found in the article by A. K. O'Brien and C. N. Bowman* on page 176
Large time behaviour of flows of compressible, viscous, and heat conducting fluids
Authors: Feireisl Eduard , Novotný Antonín
Published: February 2006

We give a complete description of large time behaviour of admissible variational solutions to the Navier–Stokes–Fourier system describing flows of viscous compressible fluids under action of arbitrarily large potential and non‐potential stationary forces. The pressure is supposed to be an affine function of temperature with coefficients depending on density and the system is thermally and mechanically isolated. Copyright © 2006 John Wiley & Sons, Ltd.
Green tea catechins as brain‐permeable, natural iron chelators‐antioxidants for the treatment of neurodegenerative disorders
Authors: Mandel Silvia , Amit Tamar , Reznichenko Lydia , Weinreb Orly , Youdim Moussa B. H.
Published: February 2006

Neurodegeneration in Parkinson's, Alzheimer's, or other neurodegenerative diseases appears to be multifactorial, where a complex set of toxic reactions, including oxidative stress (OS), inflammation, reduced expression of trophic factors, and accumulation of protein aggregates, lead to the demise of neurons. One of the prominent pathological features is the abnormal accumulation of iron on top of the dying neurons and in the surrounding microglia. The capacity of free iron to enhance and promote the generation of toxic reactive oxygen radicals has been discussed numerous times. The observations that iron induces aggregation of inert α‐synuclein and beta‐amyloid peptides to toxic aggregates have reinforced the critical role of iron in OS‐induced pathogenesis of neurodegeneration, supporting the notion that a combination of iron chelation and antioxidant therapy may be one significant approach for neuroprotection. Tea flavonoids (catechins) have been reported to possess divalent metal chelating, antioxidant, and anti‐inflammatory activities, to penetrate the brain barrier and to protect neuronal death in a wide array of cellular and animal models of neurological diseases. This review aims to shed light on the multipharmacological neuroprotective activities of green tea catechins with special emphasis on their brain‐permeable, nontoxic, transitional metal (iron and copper)‐chelatable/radical scavenger properties.
Coverage area management for wireless sensor networks
Authors: Siqueira Isabela G. , Ruiz Linnyer Beatrys , Loureiro Antonio A. F. , Nogueira José Marcos
Published: February 2006

In this work, we present a self‐management service for Wireless Sensor Networks (WSNs) that automatically controls the network redundancy. Based on a density control function, this service improves the monitoring potential of the sensor nodes. Our simulation experiments show that this self‐management service provides good and lasting coverage, as desired by WSNs applications. Copyright © 2006 John Wiley & Sons, Ltd.
Assessment of mathematics and reading performance: An examination of the correspondence between direct assessment of student performance and teacher report
Authors: Eckert Tanya L. , Dunn Erin K. , Codding Robin S. , Begeny John C. , Kleinmann Ava E.
Published: February 2006

Teacher judgments have been identified as a primary source of information regarding student academic achievement. Research examining the accuracy of teachers' judgments in assessing students' academic abilities has shown relatively high accuracy. However, previous studies have relied primarily on norm‐referenced measures to obtain estimates of students' achievement in reading and mathematics. Recent developments in the assessment of students' academic skills, such as Curriculum‐Based Measurement (CBM), provide a direct estimate of students' skill levels in basic areas such as reading and mathematics. The purpose of the present study was to examine the extent to which teachers' perceptions of students' reading and mathematics skills corresponded to direct estimates of students' reading and mathematics skills. Two second‐grade teachers estimated the reading and mathematics skills of 33 second‐grade students. Results of this study indicated that teachers were not accurate in assessing their students' mathematics functioning. Teachers were more accurate in assessing the occurrence of Mastery mathematics levels in basic addition, but were very inaccurate in assessing the occurrence of Mastery, Instructional, or Frustrational mathematics levels in all other skills assessed. In reading, teachers' judgment accuracy varied as a function of grade‐level material and instructional level. Specifically, teachers experienced considerable difficulty accurately identifying students who were reading at a Mastery level in grade‐level or above‐grade‐level material. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 247–265, 2006.
Academic resilience and its psychological and educational correlates: A construct validity approach
Authors: Martin Andrew J. , Marsh Herbert W.
Published: February 2006

This study examines educational and psychological correlates of academic resilience using within‐network and between‐network validity approaches. Based on a sample of 402 Australian high‐school students, a newly developed unidimensional academic resilience construct found within‐network validity by way of sound item and factor properties. In terms of between‐network validity, correlation, path analysis, and cluster analysis showed that five factors predict academic resilience: self‐efficacy, control, planning, low anxiety, and persistence. Hence, a 5‐C model of academic resilience is proposed: confidence (self‐efficacy), coordination (planning), control, composure (low anxiety), and commitment (persistence). Path analysis also showed that academic resilience subsequently predicts three educational and psychological “outcomes”: enjoyment of school, class participation, and general self‐esteem. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 267–281, 2006.
Academic underachievement: Relationship with cognitive motivation, achievement motivation, and conscientiousness
Authors: Preckel Franzis , Holling Heinz , Vock Miriam
Published: February 2006

In this study, the role of need for cognition, achievement motivation, and conscientiousness on academic underachievement was investigated. Forty‐seven male and 46 female students in Grades 7 to 10 participated in the study. Student attributes were assessed by self‐report measures, school performance by academic grades, and intellectual abilities by a standardized structure of intelligence test. A regression analytic model (prediction of grade point average by general intelligence) was used to operationally define underachievement. A categorical cutoff definition as well as a continuous definition was investigated. All relationships between underachievement scores and need for cognition, achievement motivation scales, and conscientiousness showed linearity. This warranted the use of a continuous definition of underachievement. Results revealed that need for cognition as well as facilitating anxiety contributed the most to the explanation of underachievement. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 401–411, 2006.
Bronchodilator effect of salbutamol from two different spacer devices
Authors: Li Albert M. , Tsang Tony , Wong Eric , Chan Dorothy , Sung Rita , Ng Pak C.
Published: February 2006

Our aim was to compare the bronchodilator effect of salbutamol delivered via a new holding chamber (Volumatic Soft, VS) with that of an established device (Volumatic, V) in asthmatic children. Children with stable asthma were recruited. They inhaled 100 µg, and 10 min later, 300 µg of salbutamol aerosol delivered via VS or V on day 1, and vice versa on day 2. Spirometry was measured at baseline, 10 min after 100 µg, and 15 min after 300 µg of salbutamol were given. The preference for either device was assessed by visual analogue score. Forty‐four children with a median age of 9.2 years (interquartile range, 8.0–10.7) completed the study. There were significant improvements in forced expired volume in 1 sec (FEV1) with time throughout the study period for both V and VS (linear and quadratic trend P < 0.001). There was a statistically significant difference in postbronchodilator FEV1 between V and VS (P = 0.013). VS gave an overall greater change in FEV1 than V, by 1.8%. The preference scores for V and VS were 7.0 (IQR 5.0–8.0) and 9.0 (IQR 8.0–10.0) (p < 0.0005), respectively. In conclusion, comparable clinical efficacy was found for V and VS with respect to changes in FEV1 after salbutamol. Patients also showed a strong preference for the new device. Pediatr Pulmonol. © 2006 Wiley‐Liss, Inc.
On the growth mechanisms of nanocrystalline diamond films
Authors: Kulisch Wilhelm , Popov Cyril
Published: February 2006

Nanocrystalline diamond/amorphous carbon (NCD/a‐C) composite films have been deposited by microwave chemical vapour deposition from methane‐rich CH4/N2 mixtures and characterized carefully by a variety of methods with respect to morphology and structure, composition, crystallinity, and bonding environment. The films consist of diamond nanocrystals of 3–5 nm diameter, which are embedded in an amorphous carbon matrix of 1–1.5 nm width. The matrix is a mixture of sp2 (20–30%) and sp3 bonded carbon and contains about 20% of hydrogen, mostly bonded to sp3 carbon atoms. New experiments are reported carried out to study the nucleation and the growth on a microscopic and macroscopic scale. No differences to standard deposition of polycrystalline diamond (PCD) with respect to the nucleation step were observed, i.e. in order to achieve a high nucleation density an appropriate substrate pretreatment is required. In contrast, there are strong differences in the growth mechanisms of NCD and PCD, respectively. Most importantly, there is a high rate of secondary nucleation observed in NCD deposition. On a macroscopic scale, this leads to a spherulitic growth of NCD films. The microscopic mechanisms leading to this high rate of secondary nucleation are discussed in terms of the deposition parameters leading to NCD growth, namely gas phase constituents and composition, pressure, substrate temperature, and bias voltage. Defect formation under the special conditions of NCD deposition is identified as a major reason. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of adsorbates on the piezoresponse of KNbO3
Authors: Peter F. , Kubacki J. , Szot K. , Reichenberg B. , Waser R.
Published: February 2006

We report on the reduction of piezoresponse in KNbO3 originating from a surface layer. An analysis with surface sensitive measurements shows that this layer consists of chemisorbates and physisorbates. Heating the sample under ultra high vacuum conditions removes the surface layer on the perovskite to a large extend. This treatment has a drastic effect on the piezoresponse as the potential difference applied to the sample is no longer reduced by a voltage drop across the adsorbate layer, leading to a higher electric field compared to the case with an adsorbate layer. Experiments and simulations are presented confirming this postulation on KNbO3. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variability in riverine ecosystems
Authors: Thoms Martin C.
Published: February 2006

Riverine ecosystems are complex features of the landscape displaying structures and processes that reflect the influence of many variables at a range of scales. Thus, the physical, chemical and ecological character of riverine ecosystems differs between them and may change over time, often at different rates and in different ways. In addition, the structure and function of riverine ecosystems also varies downstream. Rivers are process‐response systems whereby changes to discharge and sediment load induce a range of ecosystem responses. Those river systems subject to highly variable process regimes may be expected to exhibit enhanced levels of complexity and display processform relationships commensurate of this variability, where both equilibrium and non‐equilibrium conditions can exist. The process‐form relationships and interactions between the physical, chemical and ecological templates of highly variable riverine ecosystems challenge some of the accepted wisdoms of river system functioning. This paper introduces some of these challenges and the general theme of the ten papers of this special issue of River Research and Applications. As a collective they apply an interdisciplinary approach to the study and management of variability in riverine ecosystems and in doing so advance our knowledge of these systems. Copyright © 2006 John Wiley & Sons, Ltd.