bluuebunny/crossref_metadata_2025 huggingface dataset:
Why do crown ethers activate enzymes in organic solvents?
Authors: van Unen Dirk‐Jan , Engbersen Johan F. J. , Reinhoudt David N.
Published: August 2002

One of the major drawbacks of enzymes in nonaqueous solvents is that their activity is often dramatically low compared to that in water. This limitation can be largely overcome by crown ether treatment of enzymes. In this paper, we describe a number of carefully designed new experiments that have improved the insights into the mechanisms that are operative in the crown ether activation of enzymes in organic solvents. The enhancement of enzyme activity upon addition of 18‐crown‐6 to the organic solvent can be reconciled with a mechanism in which macrocyclic interactions of 18‐crown‐6 with the enzyme play an important role. Macrocyclic interactions (e.g., complexation with lysine ammonium groups of the enzyme) can lead to a reduced formation of inter‐ and intramolecular salt bridges and, consequently, to lowering of the kinetic conformational barriers, enabling the enzyme to refold into thermodynamically stable, catalytically (more) active conformations. This assumption is supported by the observation that the crown‐ether‐enhanced enzyme activity is retained after removal of the crown by washing with a dry organic solvent. A much stronger crown ether activation is observed when 18‐crown‐6 is added prior to lyophilization, and this can be explained by a combination of two effects: the before‐mentioned macrocyclic complexation effect, and a less specific, nonmacrocyclic, lyoprotecting effect. The magnitude of the total crown ether effect depends on the polarity and thermodynamic water activity of the solvent, the activation being highest in dry and apolar media, where kinetic conformational barriers are highest. By determination of the specific activity of crown‐ether‐lyophilized enzyme as a function of the enzyme concentration, the macrocyclic crown ether (linearly dependent on the enzyme concentration) and the nonmacrocyclic lyoprotection effect (not dependent on the enzyme concentration) could be separated. These measurements reveal that the contribution of the nonmacrocyclic effect is significantly larger than the macrocyclic refolding effect. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 248‐255, 2002.
Production of teicoplanin by Actinoplanes teichomyceticus in continuous fermentation
Authors: Vara Antonio Gonzalez , Hochkoepple Alejandro , Nielsen Jens , Villadsen John
Published: August 2002

Production of the potent antibiotic teicoplanin by Actinoplanes teichomyceticus was studied in batch and in chemostat cultures. It is found that the producing strain deactivates to a non‐producing strain named NP‐12. This strain is used to find the growth kinetics of the A. teichomyceticus without interference from the product teicoplanin. In batch experiments with NP‐12 grown on glucose at different initial concentrations and with different added amounts of teicoplanin, the strong inhibitory effect of teicoplanin was determined. These results obtained on NP‐12 were validated in a series of chemostat experiments with the processing strain. All experiments in batch and in chemostat cultures were well represented by Monod kinetics with respect to the carbon and energy source (glucose) and with a substantial inhibitory effect of teicoplanin. Further experiments were made with the producing strain in a continuous reactor coupled to a microfilter that delivers a cell‐free permeate. It was found that the derived kinetics almost exactly simulated the behavior of the cell recirculation reactor in addition to when the cell concentration in the reactor was more than four times higher than in the chemostat. For industrial production of teicoplanin, a continuous reactor with cell recirculation and working with a low effluent glucose concentration was by far the best mode of operation. Finally, the deactivation of the producing strain to NP‐12 was modeled by a two‐step deactivation mechanism. Deactivation was independent of dilution rate but dependendest on the inoculum preparation and on the previous history of the inoculum. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 589–598, 2002; DOI 10.1002/bit.10137
Quantitative determination of cellulase concentration as distinct from cell concentration in studies of microbial cellulose utilization: Analytical framework and methodological approach
Authors: Lynd Lee R. , Zhang Yiheng
Published: August 2002

In analyzing microbial cellulose utilization, it would be useful to independently measure the mass concentration of cells and cellulase enzymes. Such measurements would allow investigation of the allocation of cellular resources between synthesis of cells and cellulase, in vivo cell‐ and cellulase‐specific cellulose hydrolysis rates, and bioenergetics. Methodological protocols are not established for independent determination of cell and cellulase concentrations for the common case in which a substantial fraction of cellulase is attached to the cell surface. Alternative analytical approaches by which to develop such protocols are examined from the perspective of error minimization. For cell concentration measurement, acceptable accuracy is expected when the concentrations of a cell‐specific component (e.g., DNA) is determined or when total protein is determined in conjunction with a measurement specific to cellulase. For cellulase concentration measurement, acceptable accuracy is expected when a measurement specific to cellulase such as ELISA is used. Several analytical approaches are rejected based on large expected errors. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 467–475, 2002; DOI 10.1002/bit.10142
Effects of osmoprotectant compounds on NCAM polysialylation under hyperosmotic stress and elevated pCO2
Authors: Schmelzer Albert E. , Miller William M.
Published: August 2002

Elevated osmolality and pCO2 have been shown to alter sialylation in a protein‐specific manner. In Chinese hamster ovary (CHO)MT2‐l‐8 cells, tPA sialylation changed only slightly from 40 to 250 mm Hg pCO2, whereas neural cell adhesion molecule polysialic acid (NCAM PSA) content decreased by up to 70% at 250 mm Hg pCO2, pH 7.2. NCAM PSA content also decreased with increasing NaCl or NH4Cl concentration. This suggests that PSA content is a sensitive indicator of conditions that may alter glycosylation. Amino acids and their derivatives have been used to protect hybridoma and CHO cell growth under hyperosmotic stress. We examined the impact of osmoprotectants on NCAM PSA content in CHO MT2‐1‐8 cells under hyperosmolality (up to 545 mOsm/kg) and at 195 and 250 mm Hg pCO2. NCAM PSA content at 545 mOsm/kg was at least two‐fold greater in the presence of glycine betaine or L‐proline compared to that without osmoprotectant. Surprisingly, in the presence of 20 mM glycine betaine, PSA levels were 50–60% of the control level for osmolalities ranging from 320 to 545 mOsm/kg. Thus, glycine betaine inhibits NCAM polysialylation at osmolalities below 435 mOsm/kg and is beneficial at higher osmolalities. In contrast to glycine betaine, L‐proline increased PSA content by 25–120% relative to the unprotected culture at ≤545 mOsm/kg. The decrease in NCAM PSA levels of CHO MT2‐1‐8 cells cultured at 195 mm Hg pCO2–435 mOsm/kg was not mitigated by the presence of 25 mM glycine betaine, glycine, or L‐threonine, even though all of these compounds enhanced cell growth. At 250 mm Hg pCO2, all osmoprotectants tested (20 mM L‐threonine, L‐proline, glycine, or glycine betaine) increased NCAM polysialylation, with 20 mM glycine betaine restoring NCAM PSA to near control levels. Thus, osmoprotectants may (partially) offset changes in glycosylation, as well as the inhibition of growth, in cells under environmental stress. Supernatant β‐galactosidase levels, which increase upon alkalization of acidic organelles, did not differ significantly under elevated pCO2 and hyperosmolality from that at control conditions. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 359–368, 2002; DOI 10.1002/bit.10175
Design of transgenes for efficient expression of active chimeric proteins on mammalian cells
Authors: Liao Kuang‐Wen , Chou Wan‐Chih , Lo Yu‐Chih , Roffler Steve R.
Published: August 2002

Heterologous proteins expressed on the surface of cells may be useful for eliciting therapeutic responses and engineering new extracellular properties. We examined factors that control the membrane targeting of α‐fetoprotein (AFP) and a single‐chain antibody (scFv). Chimeric proteins were targeted to the plasma membrane by employing the transmembrane domain (TM) and cytosolic tail of murine CD8O (B7‐1), the TM of the human platelet‐derived growth factor receptor (PDGFR), the glycosylphosphatidylinositol anchor encoded by the C‐terminal extension of decay‐accelerating factor (DAF), and the TM of the H1 subunit of the human asialoglycoprotein receptor (ASGPR). AFP chimeric proteins containing the B7, DAF, ASGPR, or PDGFR targeting domains displayed half‐lives of 12.2, 3.8, 2.4, and 1.6 h, respectively. The newly synthesized B7 chimera was rapidly transported and remained on the cell surface. Glycosylphosphatidylinositol‐anchored chimeras reached the surface more slowly and significant amounts were released into the culture medium. PDGFR TM chimeras were rapidly degraded, whereas ASGPR chimeras were retained in the endoplasmic reticulum (ER). The surface expression of both AFP and scFv chimeric proteins followed the order (highest to lowest) of B7 > DAF >> PDGFR. Introduction of a dimerization domain (hinge—CH2—CH3 region of human IgG1) between scFv and TM dramatically reduced cleavage of the chimeric protein, increased surface expression, and produced biologically active scFv. Our results indicate that transgenes designed for the expression of active scFv on cells should incorporate a TM that does not undergo endocytosis, include an intact cytoplasmic domain, and possess a spacer to reduce cleavage and retain biological activity. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 313–323, 2001.
In vivo dynamics of galactose metabolism in Saccharomyces cerevisiae: Metabolic fluxes and metabolite levels
Authors: Ostergaard Simon , Olsson Lisbeth , Nielsen Jens
Published: August 2002

The dynamics of galactose metabolism in Saccharomyces cerevisiae was studied by analyzing the metabolic response of the CEN.PK 113‐7D wild‐type strain when exposed to a galactose pulse during aerobic growth in a galactose‐limited steady‐state cultivation at a dilution rate of 0.097 h−1. A fast sampling technique and subsequent methanol‐chloroform/solid phase extractions were applied for in vivo measurements of the dynamic changes of the AMP, ADP, ATP levels and the sugar phosphates of the Leloir pathway. The ATP level was found to be significantly lower for yeast growing under galactose limitation (0.37 ± 0.05 μmol/g CDW) than what has been reported for growth under glucose limitation. The galactose pulse of 5.58 mM was consumed within 40 min (t = 40) and 7 min after the pulse was added cell growth stopped. Subsequently, the cells started to grow and at t = 30 the specific growth rate had recovered to half the steady‐state growth rate (0.047 h−1). To evaluate the change in flux distribution at steady state and during the galactose transient, a stoichiometric model describing the aerobic metabolism of S. cerevisiae was set up for quantification of the metabolic fluxes. At t = 7 the flux entering the TCA cycle was low and acetate and ethanol started to be excreted to the extracellular medium. During recovery of cell growth the flux entering the TCA cycle increased again, and at t = 30 this flux exceeded the corresponding steady‐state flux. During the pulse an enhanced level of Gal‐1P was measured, which may be responsible for a toxic metabolic response in S. cerevisiae. The increase in the Gal‐1P concentration is intensified by the low affinity of Gal7 towards Gal‐1P and, hence, under the physiological conditions examined Gal7 seems to exert control over flux through the Leloir pathway. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 412–425, 2001.
Influence of anaerobic culture acclimation on the degradation kinetics of various substrates
Authors: Gavala H. N. , Lyberatos G.
Published: August 2002

The adaptation of an anaerobic culture (anaerobic sludge) to a specific substrate brings significant changes to its microbial population. These changes can be described by the sludge's ability to treat various substrates such as carbohydrates or proteins or “intermediate” products of anaerobic metabolism such as L‐lactic, propionic, and acetic acids. The activity of the sludge with respect to a specific substrate is a critical parameter, because the anaerobic degradability of wastewaters depends strongly on it. This work examines and quantifies the differentiation of two anaerobic sludges of the same origin, following an adaptation period of about 18 months to lactose and gelatin, respectively. The acclimation has a significant effect on the maximum specific utilization rates of various compounds and on their apparent consumption kinetics. It is noticeable, however, that even if the anaerobic cultures were not exposed to a specific substrate for a prolonged period of time (more than a year), they still kept the ability of hydrolyzing or degrading it. In addition, the acclimation has an unquestionable effect on the stoichiometry of the production of volatile fatty acids and L‐lactate. Finally, from codigestion experiments it is shown that codigestion of lactose and gelatin appears to have no effect on their hydrolysis kinetics in any of the lactose or gelatin acclimated cultures; specifically, the hydrolysis kinetics remained the same as calculated when lactose or gelatin were the only fed substrates. Similarly, the kinetics of L‐lactate and D‐glucose biodegradation seemed to be unchanged. On the other hand, codigestion has a significant effect on the production of L‐lactic, propionic, and acetic acids, which can be attributed to the increased hydrogen production accompanying gelatin biodegradation. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 74: 181–195, 2001.
Reaction of mock jurors to testimony of a court appointed expert
Authors: Cooper Joel , Hall Joan
Published: August 2002

A study was conducted to assess the impact of court appointed experts on the judgments of mock jurors. A civil proceeding was adopted for the experiment. Mock jurors heard testimony about a plaintiff's injury in an automobile accident. In some conditions, medical testimony for the plaintiff and defendant was provided by experts hired by each side. In other conditions, a medical expert appointed by the court testified in addition to the two adversarial experts. In one of these conditions, the court expert sided with the plaintiff; in another, the expert sided with the defendant. The plaintiff in the case was always an individual. The defendant was sometimes a corporation and sometimes an individual. The results showed that mock jurors sided with the court appointed expert in every condition except when the expert favored a corporate defendant. The results were discussed in terms of heuristic processing of persuasive information. Copyright © 2000 John Wiley & Sons, Ltd.
A review and update on the practice of evaluatingMirandacomprehension
Authors: Oberlander Lois B. , Goldstein Naomi E.
Published: August 2002

This article summarizes recent developments in constitutional law relevant to theMirandawarning. We describe the origins of the warning, concerns about the use of theMirandawarning, perspectives on the utility of the warning, and the relevance of the warning. We describe how the warning has changed over time, requirements for administering the warning, and procedures that police use in delivering the warning and obtaining confessions. We review case law relevant to “coerced”Mirandawaivers and confessions, changes over time in the court's interpretation of what constitutes “coercion,” use of the warning with special populations, and the recent focus in case law on individual factors that might impairMirandacomprehension. We review empirical research on factors associated with deficits inMirandacomprehension. We integrate case law rulings and empirical research into suggested approaches to forensic assessment ofMirandacomprehension. Copyright © 2001 John Wiley & Sons, Ltd.
Compartment syndrome of the foot
Authors: Andermahr Jonas , Helling Hans Joachim , Tsironis Kostas , Rehm Klaus Emil , Koebke Jürgen
Published: August 2002

The hindfoot compartment syndrome occurs in 10% of cases after calcaneal fracture. We analyzed the pathological anatomical reasons for this syndrome using the 10 feet from cadavers plastinated and cut into 4‐mm thick sequential sections. CT scans of patients with calcaneal fractures were then compared with the anatomical findings. The key component of this compartment syndrome is the quadratus plantae muscle. The sustentacular calcaneal fragment causes bleeding from the bone or the medial calcaneal arteries into this compartment. The medial and lateral plantar nerves and vessels are then compressed between the quadratus plantae muscle and the short flexor digitorum muscle. Relieving pressure by surgical decompression of the quadratus plantae compartment via a medial or plantar approach is the recommended treatment. Clin. Anat. 14:184–189, 2001. © 2001 Wiley‐Liss, Inc.
Three‐dimensional cephalometry using individual skeletal laser technology models
Authors: Z'Graggen Marcel , Schiel Harald J. , Kunz Christoph , Lambrecht J. Thomas
Published: August 2002

When planning operations on the facial skull, transversal asymmetries of the maxillo‐mandibular complex cannot be adequately assessed using conventional two‐dimensional (2D) x‐ray cephalometry. On eight patients who presented with facial skull asymmetries, a three‐dimensional (3D) laser technology model (LTM) using CT data was fabricated. Five sagittal plane points and six symmetry points were marked on the LTM, measured with the FlashPoint® 3‐D Digitizer and then geometrically converted, such that using the sagittal plane points, sella, basion, and nasion, a method could be developed that allowed the localization of each spatial point in the three symmetry planes. Thus one could quantitatively record a patient's specific facial skull asymmetry in all three planes and a 3D measurement became feasible. Based on the measurements, the asymmetry could be assessed with respect to the sagittal, vertical, and horizontal planes. With the 3‐D LTM Digitizer measuring system, the surgeon now had precise numerical information regarding the symmetry ratios of the skull at his disposal, information that would have been difficult to evaluate solely using a model analysis. The results from this study show that our measuring system is applicable and useful for complex maxillofacial asymmetries. The planning of surgical interventions was optimized because precise numerical values regarding the degree of the asymmetry were available. With the 3‐D LTM Digitizer measuring system, cephalometric analysis of complex asymmetries in the three spatial planes can be pragmatically supported. Clin. Anat. 14:258–268, 2001. © 2001 Wiley‐Liss, Inc.
Computational and experimental dynamics project for an integrated engineering curriculum
Authors: Smolinski Patrick , Hake Richard , Onipede Dipo , Miller Mark C.
Published: August 2002

An experimental and computational bungee‐drop project for use in an integrated engineering curriculum is described. The project combines aspects of physics, computer programming, calculus, and engineering mechanics to model and analyze experiments. The prediction of a computer model is compared to the experimental results and the students find the sources of error. This project was used successfully in a university‐wide freshman engineering course that introduces computer programming and where example problems were taken from all engineering departments. © 2001 John Wiley & Sons, Inc. Comput Appl Eng Educ 9: 1–7, 2001
Package for filter design based on MATLAB
Authors: Báez‐López David , Báez‐Villegas David , Alcántara René , Romero Juan José , Escalante Tomás
Published: August 2002

Electric filters have a relevant importance in electronic systems because they are present in almost any electronic system. For example, communication systems, as many other electric systems, make intensive use of filtering to separate unwanted noise from the desired signal. Unfortunately, filter design is an intensive computational task requiring a significant amount of numerical calculations to obtain either the parameters of a filter transfer function or the element values for a filter circuit realization. This paper describes a software package whose purpose is to provide a tool to be used as a teaching aid in analog and digital filter design courses. The feature of this package is that it uses MATLAB [2] for the numerical computations. The main advantage of the filter design software package described in this paper is that makes uses of one of the MATLAB toolboxes, the signals toolbox (which is used for analog and digital filter design), but used with an interface that makes possible even to the novice user to readily design filters, either analog or digital, without any previous knowledge of MATLAB or the signals toolbox. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 9: 259–264, 2001; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.cae.10004
Intelligent computer aided design, analysis, optimization, and improvement of thermodynamic systems
Authors: Wu Chih , Sherrill Donald C.
Published: August 2002

An intelligent computer aided instruction (ICAI) software to aid teaching, design, and optimization of thermodynamic systems is presented. The concept of articulate virtual laboratory (AVL), the role of design, the ICAI software, and the use of AVL at the US Naval Academy are described. An example is used to demonstrate that using the ICAI software is indeed an effective method to analyze and improve thermodynamic systems design. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 9: 220–227, 2001; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10005
Computer package development: Applications to engineering education
Authors: Almajdoub Salah A. , Qamber Isa S.
Published: August 2002

A well developed program that uses flow graph theory to calculate the steady state probabilities is presented in this paper. Two examples are tested, and their results are successfully obtained. The first model is a seven state model and represents two transmitters fed from a common power supply unit. The second model is an eight‐state model which represents three electric generators supplying part of State of Bahrain electrical network. The high accuracy and the time saving advantages show that the proposed method gives excellent agreement with the results obtained by the Runge‐Kutta method. © 2001 John Wiley & Sons, Inc. Comput Appl Eng Educ 9: 20–25, 2001
Can spreadsheet solvers solve demanding optimization problems?
Authors: Ferreira Eugénio C. , Salcedo Romualdo
Published: August 2002

Practicing engineers resort to modular simulators or to algebraic tools such as GAMS or AMPL for performing complex process optimizations. These tools, however, have a significant learning curve unless they have been introduced at the undergraduate level beforehand. In this work we show how the Solver feature of the Excel spreadsheet can be used for the optimization of a fairly complex system, i.e., a classic solvent extraction/pollution prevention with heat integration process. The specific goal was the design optimization for continuous recovery of organic solvents (VOCs) using a gas absorption tower with solvent recovery in a stripper. It is shown that the Solver feature of the Excel spreadsheet can be used to converge on local optima for these complex systems, provided proper care is taken in the solution procedure. The complexities of optimization can also be demonstrated with this tool, as can several common pitfalls encountered during optimization. © 2001 John Wiley & Sons, Inc. Comput Appl Eng Educ 9: 49–56, 2001
The effectiveness of a computer‐based safety programme for children with severe learning difficulties
Authors: Lee Deborah , McGee Anna , Ungar Simon
Published: August 2002

This study reports the findings of a research study into the development of a safety programme for those with severe and complex learning difficulties. A full description of the study was reported in Lee et al. (1998). The aims of the study were twofold. The research was intended to fill the prevailing gap in appropriate prevention materials designed for those with severe learning difficulties. Attention was paid to the medium through which such concepts were taught and it was proposed that multimedia technology might circumvent the problems encountered when introducing personal safety to this group. The second aim was to extend knowledge of developmental concepts towards a practical and applied programme to teach safety skills. As this research involved the design and implementation of a personal safety programme for those with severe learning difficulties, the general hypothesis was that after completion of the programme, the experimental group would be significantly more able to respond to the interview vignettes. An examination of the participants' level of authority reasoning related to their performance on the safety interview was also undertaken. Copyright © 2001 John Wiley & Sons, Ltd.
Who uses services for homeless people? An investigation amongst people sleeping rough in London
Authors: Fountain Jane , Howes Samantha , Marsden John , Strang John
Published: August 2002

From a sample of 389 homeless people in London, the characteristics of those who used services for homeless people are presented and the implications for service planning and delivery explored. Staff providing services for this client group need knowledge about drug use and the confidence to work effectively with homeless drug users. Copyright © 2002 John Wiley & Sons, Ltd.
Sulphydryl groups involved in Na+–Li+ exchange in human erythrocytes
Authors: Romano L. , Sidoti A. , De Luca G. , Gugliotta T. , Romano P. , Scuteri A. , Amato A.
Published: August 2002

Oxidative stress causes cellular injury that is thought to be due to increased cytosolic cation levels. Disturbances of a variety of mechanisms which normally maintain intracellular anion/cation homeostasis, occur during oxidative stress. Reactivity of the SH‐ groups essential for oubain‐resistant Na+–Li+ exchange by N‐ethylmaleimide (NEM) and selenite was studied in human erythrocytes. In addition, the reactivity of the substances on SH‐ groups and Li+ influx have been studied as a function of pH of the medium. The results show that NEM induces an irreversible inhibition of Li+ influx. It diminishes progressively with the increasing pH of the medium. Whereas we obtain increasing intracellular Li+ concentration with the rising selenite concentration in the medium. The maximum effect with this substance is reached at about pH 8.0. We can state that the ‐SH reagents (NEM and selenite) studied behave differently: NEM inhibits Li+ influx by modifying the essential SH‐groups of the membrane proteins in such a way that the exchange is reduced, whereas it maintains the Na+ permeability almost unaltered. The slight increase in intracellular Na+ induced by selenite suggests that the oxidative changes in the intracellular sulphydryl groups may constitute an important mechanism for the regulation of the intracellular cations. Copyright © 2001 John Wiley & Sons, Ltd.
Characterization of the living skin equivalent as a model of cutaneous re‐epithelialization
Authors: O'Leary Ronan , Arrowsmith Martin , Wood Edward J.
Published: August 2002

The living skin equivalent, a three‐dimensional organotypic model, has been widely used to investigate many aspects of cutaneous biology. However, there are relatively few studies assessing how faithfully the skin equivalent reproduces normal skin biology. The skin equivalent was fabricated by seeding human epidermal keratinocytes onto the upper surface of a hydrated collagen lattice populated with human dermal fibroblasts and subsequently raised to the air–liquid interface where keratinocyte stratification and differentiation led to the formation of a tissue which showed many common morphological features to that of normal skin. Histology and immunohistochemical detection of keratinocyte integrins and matrix metalloproteinases (MMPs) were used as cytological markers to assess the accuracy of the model during cutaneous re‐epithelialization. Analysis of expression of keratinocyte integrins revealed that whilst there were a number of similarities to normal skin, skin equivalent keratinocytes appeared to be ‘activated’ and hyper‐proliferating. Wounding of the skin equivalent, by complete bisection, induced re‐epithelialization from both wound edges within 8–12 h, which completely restored the epidermis within 4 days. This migration, like that in vivo, was associated with nascent expression of MMPs and upregulation of certain integrins. However, whilst integrin expression, was similar to in vivo re‐epithelialization, there were subtle differences in the level of expression and distribution of certain integrins. Copyright © 2002 John Wiley & Sons, Ltd.
Studying transfer students: Designs and methodological challenges
Authors: Kozeracki Carol A.
Published: August 2002

This chapter discusses the different methodological perspectives of the research done on transfer students. Documents from the ERIC database and journal articles are used to answer the questions, Who is conducting research? What methods are being used to gather information? and What types of data are being collected on transfer students? Finally, this chapter presents examples of studies that have implications for researchers and other stakeholders and can be adapted at the institutional level.
Contemporary Vocational Models and Programs: What the Research Tells Us
Authors: Bragg Debra D.
Published: August 2002

Today’s community colleges are playing a major role in the workforce preparation and development of both traditional and nontraditional students. This chapter provides insights into contemporary postsecondary vocational models and delivery strategies.
Dual Enrollment in Virginia
Authors: Catron Rhonda
Published: August 2002

This chapter traces the ten‐year history of the dual enrollment program in Virginia, highlights its successes, and identifies issues that will be examined for the future. It also identifies how dual enrollment can serve the needs of rural as well as urban communities.
Evaluating the etiology of mechanical valve obstruction: Use of clinical parameters, fluoroscopy, and echocardiography
Authors: Licata Anthony , Matthai William H.
Published: August 2002

Prosthetic valve obstruction is a life‐threatening complication most commonly caused by thrombus, pannus, or both. We report a St. Jude tricuspid valve obstruction, initially treated with thrombolytic therapy, found to be caused by pannus on pathologic examination. Clinical evaluation and diagnostic evaluation with fluoroscopy and echocardiography in distinguishing pannus from thrombus are reviewed. Cathet Cardiovasc Intervent 2002;55:495–500. © 2002 Wiley‐Liss, Inc.
Complications of cardiac catheterization in the current era: A single‐center experience
Authors: Chandrasekar Baskaran , Doucet Serge , Bilodeau Luc , Crepeau Jacques , deGuise Pierre , Gregoire Jean , Gallo Richard , Cote Gilles , Bonan Raoul , Joyal Michel , Gosselin Gilbert , Tanguay Jean‐François , Dyrda Ihor , Bois Marc , Pasternac Andre
Published: August 2002

Consecutive cardiac catheterization procedures done over a 2‐yr period (April 1996 to March 1998) were prospectively analyzed to determine and characterize procedure‐related complications (in‐hospital and 1‐mo follow‐up), as they occur at present. During the study period, 11,821 procedures (7,953 diagnostic and 3,868 therapeutic) were performed. The majority of procedures (> 60%) were done in high‐risk patients. Stents were implanted in 33% of patients, and adjunctive abciximab was used in 6.6% of therapeutic procedures. The overall complication rate was 8% (3.6% of diagnostic procedures and 15.1% of therapeutic procedures). The procedure‐related mortality rates were 0.2%, 0.1%, and 0.5% for total, diagnostic, and therapeutic procedures, respectively. Cardiac complications were seen in 3.9% (1.5% of diagnostic and 9% of therapeutic procedures). Emergency cardiac surgery was required in 0.05% of the diagnostic procedure group and 0.3% of the therapeutic procedure group (total, 0.1%). Despite marked changes in patient population and practice, the complication rates of cardiac catheterization remain very low. Cathet Cardiovasc Intervent 2001;52:289–295. © 2001 Wiley‐Liss, Inc.
Long‐term outcome of patients with proximal left anterior descending coronary artery in‐stent restenosis treated with rotational atherectomy
Authors: Moreno Raúl , García Eulogio , Soriano Javier , Acosta Julio , Abeytua Manuel
Published: August 2002

Once a first interventional procedure has failed, patients with proximal left anterior descending in‐stent restenosis are frequently sent for surgical revascularization. Data on long‐term outcome in selected patients with proximal left anterior descending in‐stent restenosis treated with RA are lacking. The study's objective was to evaluate the long‐term outcome of patients with proximal left anterior descending artery in‐stent restenosis treated with rotational atherectomy. The study population is constituted by 42 patients with proximal left anterior descending in‐stent restenosis treated with rotational atherectomy. Patients were followed up for 2.1 ± 0.9 years (range, 6–54). Restenosis length was 16.5 ± 9.2 mm, and restenosis was diffuse (> 10 mm in length) in 30 (71.4%). The rotational atherectomy procedure was guided by intravascular ultrasound in 18 patients (42.9%). Maximum burr/artery ratio was > 0.7 in 24 (57.1%) patients. One patient suffered a periprocedural non–Q‐wave infarction, but no deaths, Q‐wave infarction, or new target vessel revascularization occurred during hospitalization. There were no deaths or myocardial infarctions after discharge. Sixteen patients (38.1%) needed a new revascularization, but only five (11.9%) underwent coronary bypass grafting at the end of the follow‐up (2.1 ± 0.9 years). The rate of surgical revascularization at 6 months, 1 year, and 3 years was 4.8%, 7.4%, and 18.4%, respectively. The rate of new target vessel revascularization at 6 months, 1 year, and 3 years was 16.7%, 36.5%, and 40.5%, respectively. Patients with ≤ 5 months since stent implantation had a significantly higher rate of new target vessel revascularization. Patients with proximal left anterior descending in‐stent restenosis may be safely treated with rotational atherectomy. This strategy is associated with a very good long‐term outcome, with few patients undergoing surgical revascularization. Cathet Cardiovasc Intervent 2001;52:435–442. © 2001 Wiley‐Liss, Inc.
Severe thrombocytopenia possibly related to readministration of eptifibatide
Authors: Paradiso‐Hardy Fran L. , Madan Mina , Radhakrishnan Sam , Hurden Susan , Cohen Eric A.
Published: August 2002

Thrombocytopenia following eptifibatide therapy is a rare event, and acute severe thrombocytopenia following readministration has not been reported. We describe a case of acute severe thrombocytopenia following reexposure to eptifibatide during percutaneous coronary intervention. We continue to monitor platelet counts at 2–4 hr and 16–24 hr following administration of any glycoprotein IIb/IIIa inhibitor. Cathet Cardiovasc Intervent 2001;54:63–67. © 2001 Wiley‐Liss, Inc.
Electromechanical assessment of left ventricular function following successful percutaneous coronary revascularization
Authors: Koch Karl‐Christian , Wenderdel Monika , Stellbrink Christoph , Hanrath Peter , vom Dahl Juergen
Published: August 2002

Percutaneous electromechanical mapping was applied to evaluate the impact of coronary revascularization on electrical and mechanical parameters in patients with prior myocardial infarction. In 15 patients with prior (≥ 4 weeks) myocardial Q‐wave infarction and regional wall motion abnormalities, left ventricular endocardial mapping was performed immediately prior to percutaneous coronary revascularization. Patients underwent repetitive mapping during 6‐month follow‐up angiography with good revascularization results in all patients. Mean regional unipolar electrogram (UP) amplitude of all regions remained unchanged (10.4 ± 4.2 mV prerevascularization vs. 10.2 ± 4.4 mV postrevascularization), whereas mean local shortening (LS) of all regions increased from 6.0% ± 5.8% to 9.7% ± 5.3% (P < 0.001). The percentage of electromechanical match regions (LS < 6% and UP < 9 mV) remained unchanged after revascularization (15% vs. 10%; NS), whereas the percentage of mismatch regions (LS < 6% and UP > 9 mV) declined from 38% to 10% (P < 0.0001). We conclude that electromechanical mapping allows the sensitive detection of improved mechanical function after successful revascularization. Electrical activity remains unchanged 6 months after revascularization and the number of regions with an electromechanical mismatch decrease. Cathet Cardiovasc Intervent 2001;54:466–472. © 2001 Wiley‐Liss, Inc.
Percutaneous closure of postmyocardial infarction ventricular septal defect with the CcardioSEAL septal occluder implant
Authors: Pienvichit Pavit , Piemonte Thomas C.
Published: August 2002

Postinfarction ventricular septal rupture carries a poor prognosis with medical or surgical treatment. We report on successful deployment of CardioSEAL septal occluder implant for postinfarct septal defect in a high‐surgical‐risk patient. Cathet Cardiovasc Intervent 2001;54:490–494. © 2001 Wiley‐Liss, Inc.
Felt tip pens and school councils: children's participation rights in four English schools
Authors: Wyse Dominic
Published: August 2002

The United Nation Convention on the Rights of the Child has created practical challenges for nation states and institutions particularly in relation to children's rights to participation. The limited research that is available has tended to use survey methodology; qualitative accounts of children's daily lives are rare. The present study investigated the nature of children's participation in their education in two primary and two secondary schools; in particular the right to express views freely in all matters affecting the child. The study found that children's opportunities to express their views were extremely limited even when school councils were in place. It is concluded that the goal of active citizenship espoused by recent national curriculum developments will remain illusive unless educational practice changes to a focus on school processes rather than products. Copyright © 2001 John Wiley & Sons, Ltd.
Towards multiporphyrinic α‐helices with a polypeptidic backbone as system endowed with light harvesting capabilities
Authors: Solladié Nathalie , Hamel Arnaud , Gross Maurice
Published: August 2002

Starting from a porphyrin functionalized derivative of the L‐lysine, three peptides, bearing, respectively, two, four, and eight chromophores, were synthesized using an iterative synthetic strategy based on the choice of mild conditions for the deprotection steps. Chirality 13:736–738, 2001. © 2001 Wiley‐Liss, Inc.
Stereospecific pH‐dependent degradation kinetics of R‐ and S‐naproxen‐β‐l‐O‐acyl‐glucuronide
Authors: Mortensen Rasmus Worm , Sidelmann Ulla Grove , Tjørnelund Jette , Hansen Steen Honoré
Published: August 2002

The hydrolysis and acyl migration of biosynthetic S‐naproxen‐β‐l‐O‐acyl glucuronide (I) and R‐naproxen‐β‐l‐O‐acyl glucuronide (II) was followed by HPLC. Nine first‐order kinetic rate constants for the hydrolysis and acyl migration between the β‐l‐O‐acyl glucuronide, its α/β‐2, α/β‐3‐, α/β‐4‐, and α‐1‐O‐acyl isomers and naproxen aglycone were determined for I and II at pH 7.00, 7.40 and 8.00 at 37°C by kinetic simulation. For I the 3‐O‐acyl isomer was the most stable isomer as the pseudo‐equilibrium ratio for the major acyl‐migrated isomers was 1:1.5:0.9 (2‐O‐acyl isomer:3‐O‐acyl isomer:4‐O‐acyl isomer). The 3‐ and 4‐O‐acyl isomers of II were equally stable as the pseudo‐equilibrium ratio for the major acyl‐migrated isomers was 1:1.4:1.4 (2‐O‐acyl isomer:3‐O‐acyl isomer:4‐O‐acyl isomer). For both I and II, the pseudo‐equilibrium ratio between the major 2‐O‐acyl isomer and the minor α‐l‐O‐acyl isomer was 10:1 (2‐O‐acyl isomer:α‐l‐O‐acyl isomer). The pseudo‐equilibrium found for the major acyl‐migrated isomers of I and II in the present study corresponds with the pattern previously published for R‐ and S‐ketoprofen‐β‐l‐O‐acyl glucuronide acyl‐migrated isomers, suggesting that these findings may be general for acyl‐migrated β‐l‐O‐acyl glucuronides of enantiomeric 2‐arylpropionic acids. Chirality 14:305–312, 2002. © 2002 Wiley‐Liss, Inc.
Enantioselective conjugate addition of diethylzinc to cyclic enones catalyzed by copper complexes of methylene‐bridged P‐chirogenic diphosphines
Authors: Taira Shin'ichi , Crépy Karen V.L. , Imamoto Tsuneo
Published: August 2002

The copper‐catalyzed enantioselective conjugate addition of diethylzinc to 2‐cyclohexen‐1‐one was investigated using (R,R)‐bis‐(t‐butylmethylphosphino)methane (1c) as a chiral ligand. The reaction was carried out at 0°C in THF‐toluene as the solvent system and in the presence of 1.2 mol% of CuOTf afforded (S)‐3‐ethylcyclohexan‐1‐one with 85% ee. Chirality 14:386–392, 2002. © 2002 Wiley‐Liss, Inc.
Video‐microscopy observations of fast dynamic processes in the protozoon Giardia lamblia
Authors: Campanati Loraine , Holloschi Andreas , Troster Helmut , Spring Herbert , Souza Wanderley de , Monteiro‐Leal Luiz Henrique
Published: August 2002

Video‐microscopy in combination with digital image processing was used to analyze dynamic processes associated to the life cycle of Giardia lamblia trophozoites. These parasites swim and attach to the epithelial cells, producing the disease known as Giardiasis. Giardia is a multiflagellar cell, presenting 4 pairs of flagella. With the use of analogue and digital tools, we observed that in cells attached to glass slides only 2 of the 4 pairs present active beating (wave propagation). The frequency observed was 17–18 Hz to the anterior and 8–11 Hz to the ventral flagella. These data resulted from several hours of recording using both analogue video and high‐speed digital camera. The caudal pair did not show active beating patterns and the same holds true for the posterior one. In this latter pair, oscillations were observed, but they were always associated to the transit of the wave produced by the ventral pair. The analysis performed with free moving cells showed that during its forward dislocation, Giardia lamblia presented either a lateral rocking or a complete rotational (tumbling) movement around its longitudinal axis. A dislocation of the caudal region of the cell both in the lateral and dorso‐ventral direction was observed. This movement was completely independent from the flagellar beating and it is likely to be produced by a microtubular complex located in the caudal portion of the cell. The adhesion process of Giardia lamblia was also followed by video‐microscopy and the data showed that the ventral disk had an active participation in this process. Cell Motil. Cytoskeleton 51:213–224, 2002. © 2002 Wiley‐Liss, Inc.
Kinesin‐II is not essential for mitosis and cell growth in Chlamydomonas
Authors: Matsuura Kumi , Lefebvre Paul A. , Kamiya Ritsu , Hirono Masafumi
Published: August 2002

The FLA10 gene product (Fla10p) in Chlamydomonas, a heterotrimeric kinesin‐II, plays a crucial role in flagellar assembly as a motor protein driving intraflagellar transport. This protein has also been suggested to play a role in mitosis based on its localization to mitotic spindle. A role for Fla10p in mitosis has been difficult to test because to date only conditional (temperature‐sensitive) mutant alleles were available, and it is not known whether these retain residual function for mitosis at the non‐permissive temperature. In this report, we describe a null allele of fla10 produced by insertional mutagenesis. This mutant does not assemble flagella, but proliferates at a rate identical to that of wild type cells. Observation of microtubule organization in the cell body revealed that normal mitotic spindles are formed in dividing mutant cells. Thus, we conclude that FLA10 kinesin plays no significant roles in mitosis. Cell Motil. Cytoskeleton 52:195–201, 2002. © 2002 Wiley‐Liss, Inc.
Construction of a NMR‐MOUSE with short dead time
Authors: Anferova S. , Anferov V. , Adams M. , Blümler P. , Routley N. , Hailu K. , Kupferschläger K. , Mallett M.J.D. , Schroeder G. , Sharma S. , Blümich B.
Published: August 2002

The NMR‐MOUSE is a nuclear magnetic resonance (NMR) sensor for unilateral NMR of materials suitable for process and quality control. Practical aspects of the sensor construction are described, in particular radiofrequency coil design and shielding procedures to reduce probe ringing. Dead times of less than 20 μs can be achieved at frequencies in the vicinity of 20 MHz with permanent magnets within sensitive volumes up to 4 mm deep. First applications of the NMR‐MOUSE to the analysis of historical books are reported. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 15–25, 2002.
Closed‐loop feedback control of phased‐array microwave heating using thermal measurements from magnetic resonance imaging
Authors: Behnia B. , Suthar M. , Webb A. G.
Published: August 2002

Microwave heating is a promising technique for hyperthermia treatment of tumors, but is not yet a standard clinical method. Problems include the inability to control automatically and noninvasively the temporal and spatial temperature behavior. Magnetic resonance imaging (MRI) can be used to map thermal changes via phase shifts in gradient‐echo images and has recently been incorporated into simple feedback systems for ultrasound heating. In this paper, we show the first demonstration of closed‐loop feedback control of microwave heating using MRI‐derived maps of both temperature and specific absorption rate as the inputs to a feedback algorithm. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 101–110, 2002.
Adapting a hall probe controller for current control of an air‐core magnet
Authors: Rinard George A. , Quine Richard W. , Eaton Gareth R. , Eaton Sandra S.
Published: August 2002

Air‐core magnets are preferable to iron‐core magnets for electron paramagnetic resonance (EPR) magnetic fields less than ∼150 G (15 mT). The preferred way to control the field of an air‐core magnet is by direct control of the current. For imaging applications, magnetic fields produced by the gradient coils interfere with the use of the Hall sensor. Direct current control of the field avoids this problem. However, most suppliers of commercial EPR spectrometer systems provide only Hall effect control of the magnetic field. To provide direct current control of an air‐coil magnet interfaced to a commercial console, an adapter was constructed that effectively converts the Hall effect probe into a current sensor by measuring the field produced in coils carrying the same current as the main magnet coils, but positioned away from and shielded from the main magnet. The effectiveness of this approach is demonstrated. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 47–50, 2002.