bluuebunny/crossref_metadata_2025 huggingface dataset:
An apparatus for MR‐guided breast lesion localization and core biopsy: Design and preliminary results
Authors: Schneider Erika , Rohling Kenneth W. , Schnall Mitchell D. , Giaquinto Randy O. , Morris Elizabeth A. , Ballon Doug
Published: August 2002

System design and initial results are presented from a new unilateral MR‐guided breast lesion localization and core biopsy system. Over 150 imaging studies, an accuracy study on phantoms with 50 localization wire deployments and 33 core biopsy trials, and 19 clinical procedures are reported. The mean spatial accuracy from the lesion center for a 20‐gauge (G) needle (N = 13) was within 1.2 ± 1.4 mm (SD) and for a 14G biopsy (N = 4) 0.8 ± 1.1 mm. For sampling using a 16G core through a 14G needle, the mean accuracy was 5.6 mm (N = 2). The needle guide geometry imposed a small, calculable targeting error. For phantom measurements using the 20G device, the mean geometry‐induced error was 0.73 ± 0.43 mm. However, this contribution was, on average, 42% of the mean measured 2.35 ± 1.65 mm offset. The new device design provided an accurate and simple guidance method for localization or core biopsy of MR‐visible breast lesions. J. Magn. Reson. Imaging 2001;14:243–253. © 2001 Wiley‐Liss, Inc.
Numerical modelling of equilibrium charge separation in poled devices
Authors: De Francesco A. , Town G. E.
Published: August 2002

We describe an efficient numerical procedure for the equilibrium solution of the internal electric field distribution resulting from poling of photo‐refractive materials. This technique has been developed to model the equilibrium state in poled bulk devices requiring bulk charge neutrality to facilitate the modelling of blocking boundaries for a high externally applied voltage (bias) in the kV range for a small number of points. This technique is an improvement on existing conventional numerical techniques employed for modelling semiconductor devices that are intended for low bias. This method can also accommodate the modelling of planar insulators and organic optical materials. We develop an algorithm incorporating the existing Newton–Raphson method for solving Kukhtarev's equations that enforces conservation of charge within the modelled system. We apply this technique to model one‐dimensional charge separation in ultraviolet (UV) excited poling of glass and, report numerical equilibrium electric field distribution for a 2 kV bias. The convergence behaviour of the algorithm is investigated and compared against the Newton–Raphson method. Copyright © 2001 John Wiley & Sons, Ltd.
Nerve growth factor‐mediated increases in protein methylation occur predominantly at type I arginine methylation sites and involve protein arginine methyltransferase 1
Authors: Cimato Thomas R. , Tang Jie , Xu Ye , Guarnaccia Corrado , Herschman Harvey R. , Pongor Sandor , Aletta John M.
Published: August 2002

Nerve growth factor (NGF)‐specific signal transduction leads to changes in protein methylation during neuronal differentiation of PC12 cells (Cimato et al. [1997] J. Cell Biol. 138:1089–1103). In the present work, we demonstrate that, among NGF‐regulated proteins, arginine methylation is more prevalent than carboxylmethylation. Type I protein arginine methyltransferase (PRMT) activity produces asymmetric dimethylation of the terminal guanidinonitrogen of arginines in substrate proteins, particularly glycine and arginine‐rich (GAR) segments of proteins. Several GAR peptides were used to assay for methyltransferase activity and to compete with endogenous cellular proteins for the PRMT activity in PC12 cell extracts. Peptides derived from fibrillarin and nucleolin, as well as a synthetic GAR peptide containing a repetitive GRG motif, are each extremely effective at blocking in vitro methylation of the NGF‐regulated PC12 cell methylated proteins. Myelin basic protein, a substrate for type II PRMT, selectively inhibits a 45 kDa protein but is a much less effective inhibitor of total methylation at an equimolar concentration. In addition, the fibrillarin‐ and nucleolin‐derived peptides were used to detect elevated PRMT activity in homogenates of NGF‐treated PC12 cells. Finally, immunoprecipitation of PRMT1 from PC12 cells provides the first demonstration of an NGF‐activated methyltransferase and implicates PRMT1 in NGF signal transduction. © 2002 Wiley‐Liss, Inc.
Nicotine modulates the spontaneous synaptic activity in cultured embryonic rat spinal cord interneurons
Authors: Fucile Sergio , Lax Pedro , Eusebi Fabrizio
Published: August 2002

The nicotine‐induced modulation of the synaptic activity was studied in cultured spinal cord neurons from embryonic rats, using the patch‐clamp technique, alone or in combination with Ca2+ imaging. Morphologically, neurons could be divided into two populations: multipolar nerve cells and bipolar, spindle‐shaped neurons. Neurons were predominantly GABAergic, with ∼70% of bipolar cells and 60% of multipolar cells positive for GABA immunostaining. Nicotine (Nic) did not affect the activity of the spontaneous postsynaptic current (sPSC) in multipolar neurons, whereas bipolar cells responded to Nic applications with an enhancement of both inhibitory and excitatory synaptic activity (threefold for 100 μM Nic). No change in the mean event amplitude was observed. The increase of sPSC frequency was detectable at 1–10 μM Nic, and was prevented by dihydro‐β‐erythroidine (DHβE) but not by α‐bungarotoxin. Choline, a selective α7‐nAChR agonist, did not mimic the Nic action. Simultaneous treatment with inhibitors of ionotropic glutamate receptors, CNQX (20 μM) and AP5 (20 μM), completely blocked the excitatory sPSC activity but did not prevent the Nic‐induced enhancement of inhibitory sPSC activity. Tetrodotoxin (1 μM) reduced the basal spontaneous activity but did not block the Nic‐induced effects on bipolar neurons. In a subset of bipolar neurons (12%) exposed to AP5 and CNQX, Nic activated DHβE‐sensitive inward currents, associated with an elevation of cytosolic Ca2+ ([Ca2+]i). Our results provide the first evidence of modulation of both excitatory and inhibitory neurotransmitter release in embryonic spinal cord interneurons by non‐α7‐containing nicotinic receptors. © 2002 Wiley‐Liss, Inc.
Ceramide‐induced cell death in primary neuronal cultures: Upregulation of ceramide levels during neuronal apoptosis
Authors: Toman Rachelle E. , Movsesyan Vilen , Murthy Shvetha K. , Milstien Sheldon , Spiegel Sarah , Faden Alan I.
Published: August 2002

Ceramide is a sphingolipid that has been implicated both in apoptosis and protection from cell death. We show that in both rat cerebellar granule cells and cortical neuronal cultures application of C2‐ceramide causes cell death in a dose‐ and time‐dependent manner. Similar effects were observed with the exogenous application of bacterial sphingomyelinase, which hydrolyzes sphingomyelin located on the outer leaflet of the plasma membrane and leads to endogenous ceramide accumulation. Furthermore, endogenous ceramide levels were increased during apoptosis induced by nutrient deprivation or etoposide treatment. These findings suggest that upregulation of ceramide levels, which may be generated through activation of sphingomyelinase, contributes to neuronal apoptosis. © 2002 Wiley‐Liss, Inc.
Modification of representational difference analysis applied to the isolation of forskolin‐regulated genes from Schwann cells
Authors: Bermingham John R. , Shumas Sue , Whisenhunt Tom , Rosenfeld Michael G. , Scherer Steven S.
Published: August 2002

Many aspects of the response of Schwann cells to axonal cues can be induced in vitro by the adenylyl cyclase activator forskolin, yet the role of cAMP signaling in regulating Schwann cell differentiation remains unclear. To define better the relationship between cAMP signaling and Schwann cell differentiation, we used a modification of cDNA representational difference analysis (RDA) that permits the analysis of small amounts of mRNA and identified additional genes that are differentially expressed by forskolin‐treated and untreated Schwann cells. The genes that we have identified, including MKP3, a regulator of ERK signaling, and the sphingosine‐1‐phosphate receptor edg3/lpB3, may play important roles in mediating Schwann cell differentiation. J. Neurosci. Res. 63:516–524, 2001. © 2001 Wiley‐Liss, Inc.
Glutamyl cysteine synthetase catalytic and regulatory subunits localize to dopaminergic nigral neurons as well as to astrocytes
Authors: Yantiri Ferda , Gasparyan Anna , Andersen Julie K.
Published: August 2002

Glutathione (GSH) is considered one of the primary antioxidant compounds in the brain, important for the removal of peroxides from this organ. GSH levels have been reported to be significantly lower in the substantia nigra (SN) of Parkinson patients vs. age‐matched controls. Curiously, GSH has been proposed to be present in brain astrocytes rather than in neurons even though these cells are not lost in Parkinson disease. We report that the catalytic and regulatory subunit proteins of glutamyl cysteine synthetase (GCS), the primary enzyme involved in GSH synthesis, are present not only in astrocytes but also in dopaminergic neurons of the SN. This may have important implications in terms of GSH loss associated with Parkinson disease. J. Neurosci. Res. 64:203–206, 2001. © 2001 Wiley‐Liss, Inc.
Decreases in calmodulin binding proteins and calmodulin dependent protein phosphorylation in the medial preoptic area at the onset of maternal behavior in the rat
Authors: O'Day Danton H. , Lydan Michael , Watchus Jason , Fleming Alison S.
Published: August 2002

The onset of maternal behavior is characterized by the action of certain hormones, neuropeptides and neurotransmitters and a concomitant increase in the expression of c‐Fos in the medial preoptic area (MPOA) but the signaling events that lie between have not been characterized. Because several of these hormones, neuropeptides and neurotransmitters function by activating Ca2+/calmodulin (CaM) mediated signaling pathways, many of which can lead to c‐Fos expression, the goal of the current work was to identify calmodulin binding proteins (CaMBPs) or specific CaM‐dependent phosphoproteins that might be involved. Probing of SDS‐PAGE gels of extracts from the hippocampus, parietal cortex, basolateral amygdala and MPOA with recombinant 35S‐VU1‐calmodulin (CaM) revealed 30 Ca2+‐dependent and 4–6 Ca2+‐independent CaMBPs. Statistically significant maternal behavior‐related decreases in four Ca2+‐dependent CaMBPs (∼31 kDa, 50% decrease; ∼33 kDa, 32%; ∼50 kDa, 35%; ∼60 kDa, 33%) were observed specifically in the MPOA. Numerous proteins were phosphorylated in a Ca2+ CaM‐dependent manner with two (MWs ∼61 Da, ∼58 kDa) showing a lack of phosphophorylation only in the MPOA. The selective decrease in CaMBPs coupled with the absence of CaM‐dependent phosphoproteins implies that changes in Ca2+/CaM‐mediated signaling may mediate some of the MPOA‐specific processes during the onset of maternal behavior in the rat. J. Neurosci. Res. 64:599–605, 2001. © 2001 Wiley‐Liss, Inc.
Regulation of brain‐derived neurotrophic factor transcripts by neuronal activation in rat hypothalamic neurons
Authors: Marmigère Frédéric , Rage Florence , Tapia‐Arancibia Lucia
Published: August 2002

Brain‐derived neurotrophic factor (BDNF) belongs to the neurotrophin family and regulates the survival, differentiation, and maintenance of function in different neuronal populations. BDNF is strongly expressed in hypothalamic neurons, where it exerts long‐ or short‐lasting actions. Because glutamate has been associated with regulations of hypothalamic hormones, we examined the regulation of the four promoters of the BDNF gene by glutamate in fetal hypothalamic neurons. The expression levels of BDNF transcripts were investigated using semiquantitative RT‐PCR. BDNF protein was determined by enzyme immunoassay, and BDNF and Trk B (BDNF receptor) gene variations were determined by RNAse protection assay. By RT‐PCR, we showed that, under basal conditions, BDNF transcripts from exons I, II, and III but not from IV were expressed in the hypothalamic neurons. Glutamate increased expression of both the protein and the four transcripts via N‐methyl‐D‐aspartate receptors, with maximal stimulations after 3 hr of application for exon I and II mRNAs and after 1 hr for exon III and IV mRNAs. Actinomycin D blocked the increase of all transcripts, whereas cycloheximide treatment inhibited stimulation only of exon I and II mRNAs. Trk B mRNA was rapidly and transiently reduced after glutamate application. Our results demonstrate that glutamate 1) regulates BDNF mRNA expression at an early developmental stage in hypothalamic neurons and 2) exerts a differential regulation of BDNF transcripts. J. Neurosci. Res. 66:377–389, 2001. © 2001 Wiley‐Liss, Inc.
A survey of acid catalysts in dipyrromethanecarbinol condensations leading to meso-substituted porphyrins
Authors: GEIER G. RICHARD , CALLINAN JENNIFER B. , DHARMA RAO POLISETTI , LINDSEY JONATHAN S.
Published: August 2002

The successful use of dipyrromethanecarbinols in rational routes to porphyrinic macrocycles requires catalysis conditions that enable irreversible condensation, thereby avoiding substituent scrambling and formation of undesired porphyrin products. Previously, successful conditions of trifluoroacetic acid (TFA) (30 mM) in acetonitrile were identified following a lengthy survey of TFA and BF3-etherate catalysis in diverse solvents. In this study, focus was placed on the acid catalyst by examining 17 acids in CH 2 Cl 2, the traditional solvent for two-step, one-flask porphyrin syntheses. In the self-condensation of the carbinol derived from 1-(4-methylbenzoyl)-5-phenyldipyrromethane, porphyrin yields of 9–55% were obtained from the various acids, compared to 20% under TFA catalysis in acetonitrile. A number of catalytic conditions that produce little to no porphyrin in reactions of pyrrole + benzaldehyde afforded good yields of porphyrin and the suppression of scrambling in reactions of dipyrromethanecarbinols. The four best acid catalysts ( InCl 3, Sc ( OTf )3, Yb ( OTf )3, and Dy ( OTf )3) initially identified were then examined with dipyrromethanecarbinols bearing challenging substituents (alkyl, pyridyl, or no substituent). The greatest improvement was obtained with the pyridyl substrates. Selected reactions performed on a preparative scale (115 to 460 mg of isolated porphyrin) verified the results of the analytical-scale experiments and revealed the more facile isolation of the porphyrin from reactions performed in CH 2 Cl 2 rather than acetonitrile. This study provides alternatives to the use of TFA/acetonitrile that offer advantages in terms of yield and isolation of the porphyrin without sacrificing suppression of scrambling. Furthermore, the finding that poor catalysts for the benzaldehyde + pyrrole reaction can be excellent catalysts for dipyrromethanecarbinols provides guidance for the identification of other catalysts for use with reactive precursors in porphyrin-forming reactions.
Silica‐supported silver nano‐particles for surface‐enhanced Raman spectroscopy
Authors: Liu Feng Xian , Xiao Yun , Li Ying‐Sing
Published: August 2002

We have developed and prepared a new type of substrate by impregnating silica with silver for surface‐enhanced Raman scattering (SERS). The effects of several experimental conditions of preparation, including the drying temperature, the molar ratio of Ag to Si, the calcination time and the calcination temperature, were investigated and varied to give a better surface enhancement efficiency of the substrate. X‐ray diffraction and transmission electron microscopy were used to measure the relative abundance of silver metal and the size of silver particles in the substrates. The results provided useful information that would be helpful in explaining the surface‐enhanced performance of silica‐supported silver substrates prepared under different conditions. The SERS spectra of several organic dyes were used to demonstrate the performance of the silver–silica substrate. Copyright © 2001 John Wiley & Sons, Ltd.
Eating soup with a fork: how informal social networks influence innovation in high‐technology firms
Authors: Davies Philip N. , Koza Mitchell P.
Published: August 2002

High‐technology firms need to innovate effectively to survive and prosper. However, one aspect of innovation that needs more consideration is the influence of the social networks of the innovators and the decision‐makers on the innovation process.

This paper develops a model for innovation using the concept of reputation management. It is suggested that differences in the social networks of the actors involved — specifically whether they are in strong, weak or new networks — can influence the success or otherwise of that innovation.

Innovators and decision‐makers are strongly influenced by the requirement to protect and enhance their reputations. These arguments are illustrated with data from a case study from the aerospace sector.

Copyright © 2001 John Wiley & Sons, Ltd.
The development of a strategic control system for the management of strategic change
Authors: Tavakoli Iraj , Perks Keith J.
Published: August 2002

The role of goal setting in the management of strategic change and control is examined.

Three factors driving strategic change are identified that are only superficially discussed in parts of the strategy literature: Competitive Advantage, Strategic Capabilities and Industry Key Success Factors. These factors address the control requirements of emergent as well as planned strategies.

A five‐factor model is proposed which underpins the importance of planning. It recognizes the importance of emergent strategies that develop in response to changes in the internal and external environments of the firm and will assist managers in assessing, anticipating and responding to changes in industry structures and competitive forces.
Managing the outsourced workforce: strategic challenges for human resource management
Authors: Hiltrop Jean M. , Jenster Per V. , Martens Herna
Published: August 2002

For most of the twentieth century, the number of tasks and levels in large organizations grew incrementally, adding new job and career opportunities to full‐time employees. In recent years this pattern has fundamentally changed.

Global developments, both technological and economic, have led to many organizations cutting back their operations, closing facilities or outsourcing non‐core activities to specialist providers.

As we move further into the twenty‐first century, we can realistically expect that the need for cost reduction, speed and flexibility will become even greater, leading organizations to reduce the number of full‐time employees.

As labour markets are becoming tighter and supply‐driven, finding qualified staff will become more difficult and companies will increasingly have to depend on temporary staff and other types of non‐permanent employees to meet their staffing requirements.

Copyright © 2001 John Wiley & Sons, Ltd.
Effect of various indigenous processing methods on the α‐galactoside and mono‐ and disaccharide content of an Indian tribal pulse, Mucuna pruriens var utilis
Authors: Siddhuraju Perumal , Becker Klaus
Published: August 2002

The effect of various treatments, such as soaking in different solutions, cooking of raw and soaked seeds, autoclaving of raw and soaked seeds, dehusking of water‐soaked seeds, fermentation of water‐soaked/dehusked seeds, autoclaving of fermented seeds, dry heating of raw seeds and germination, on the levels of mono‐ and disaccharides and α‐galactosides in two varieties of an Indian tribal legume, mucuna bean (Mucuna pruriens var utilis), was investigated. The levels of raffinose, stachyose and verbascose decreased under various treatments. Among the different soaking and cooking/autoclaving treatments, tamarind pulp extract soaking and sodium bicarbonate solution soaking followed by autoclaving procedures were the most effective for removing α‐galactosides (68.4–70.9 and 68.5–68.9% respectively). The lowest reduction of α‐galactosides (8.4–17.2%) was observed in dry‐heated samples. Germination for more than 72 h resulted in the highest reduction of total α‐galactosides (93.6 and 89.6% in white and black varieties respectively). During the germination process, glucose, fructose and sucrose concentrations increased significantly.

© 2001 Society of Chemical Industry
A qualitative probabilistic model of microbial outbursts in foods
Authors: Engel Robert , Normand Mark D , Horowitz J , Peleg Micha
Published: August 2002

Sequences of counts of potentially harmful organisms in foods usually exhibit an irregular fluctuating pattern. The counts are determined by the interplay of numerous random factors that tend to promote or inhibit the organisms' growth. The counts can be recorded as zero, indicating that either the organism is not present or is below a minimum detectable level, or they can fluctuate randomly within characteristic bounds. An outburst is said to occur when the population surpasses a specified threshold determined by safety or quality considerations. The growth pattern in this ‘explosive’ mode is also governed by a combination of random mechanisms that determine the growth rate and eventual decline of the population. This paper presents a probabilistic model for such scenarios. The model parameters represent the underlying distribution of the fluctuations, the detection and explosion thresholds and the probability of continued growth after an outburst has begun. A simplified version of the model was used to simulate examples of microbial histories that resemble those of sensitive foods. It is also used to elucidate how the frequency, intensity and duration of outbursts are affected by the parameters of the model. In addition, we demonstrate how to estimate the model's parameters from actual records and illustrate the efficacy of the estimation method with simulated data. The utility of such models for risk assessment will depend on the availability of long records of microbial counts that include outbursts in order to test their predictive ability. Because the presence of a harmful agent is not always sufficient to cause food poisoning, models of this kind can only estimate the expected frequency of outbursts but not the frequency of actual food‐poisoning outbreaks.

© 2001 Society of Chemical Industry
Immunoreactivity of p53, Ki‐67, and c‐erbB‐2 in phyllodes tumors of the breast in correlation with clinical and morphologic features
Authors: Shpitz B. , Bomstein Y. , Sternberg A. , Klein E. , Tiomkin V. , Kaufman A. , Groisman G. , Bernheim J.
Published: August 2002

Background and Objectives

Phyllodes tumor (PT) is a biphasic tumor with unpredictable behavior. Our study aimed to evaluate clinicopathologic factors and biomarkers that may be helpful in predicting the outcome of these tumors.

Methods

We evaluated immunoreactivity of p53, c‐erbB‐2, and Ki‐67 in 23 PT treated over a 10‐year period. The proliferative activity in PT and expression of p53 and c‐erbB‐2 were correlated with clinicopathologic features of the tumors and patients' outcome.

Results

Positive stromal p53 immunoreactivity was found in PT with atypia, infiltrative borders, high cellularity, as well as in PT that displayed higher then average proliferation index, although none of these parameters reached statistical significance. There was a good correlation between proliferative stromal cell activity expressed Ki‐67–labeling index and the malignant features of the tumors. Primary tumors that recurred displayed high proliferative activity. Three of four recurrent tumors showed a progression toward higher malignant phenotype with concomitant increase in proliferative stromal cell activity. c‐erbB‐2–positive tumors had no particular histologic features or association with either p53 positivity or higher proliferative indices.

Conclusions

p53 expression tends to be more frequent in PT with higher malignant potential but did not predict recurrence. Incompletely excised tumors that recurred displayed high proliferative activity in their primary tumors. Progression toward more malignant phenotype in the recurrent PT was accompanied with increase in stromal cell proliferative activity, suggesting the presence of biological continuity between benign, borderline, and malignant PT. J. Surg. Oncol. 2002;79:86–92. © 2002 Wiley‐Liss, Inc.
Folate status among patients with non‐small cell lung cancer: A case‐control study*
Authors: Jatoi Aminah , Daly Benedict D.T. , Kramer Gertrude , Mason Joel B.
Published: August 2002

Background and Objectives

This case control study explored the purported inverse relationship between folate status and lung cancer development.

Methods

Folate status of 46 postoperative non‐small cell lung cancer (NSCLC) patients was compared to that of 44 non‐cancer patients. Cancer patients had completed treatment > 3 months prior and had no evidence of cancer. Ineligibility criteria for all patients included (1) > 2 alcoholic drinks/day (2) ongoing tobacco use, or (3) folate supplementation > 400 μg/day.

Results

No differences were found between groups in serum and RBC folate after adjustment for age and use of folate‐interfering medications: geometric means (GM) × /geometric standard error (GSE): 7.9 ng/ml ×  /1.1 vs. 7.8 ng/ml × /1.1, respectively (P = 0.91) for serum folate; 264 ng/ml × /1.1 vs. 263 ng/ml × /1.1, respectively (P = 0.97) for RBC folate. Age‐ and creatinine‐adjusted homocysteine was no different between groups: GM × /GSE: 9.4 μmol/L × /1.0 vs. 8.6 μmol/L × /1.0, respectively (P = 0.17). No difference were seen in folate intake. Frequencies of the homozygous genotype for the MTHFR polymorphism, an enzyme important in folate metabolism and associated with a reduced risk of other cancers, were no different.

Conclusions

This case control study does not support the hypothesis that low folate is an independent risk factor for NSCLC. J. Surg. Oncol. 2001;77:247–252. © 2001 Wiley‐Liss, Inc.
Kinetics of the reactions of fluorine and chlorine atoms with ethylene oxide (oxirane)
Authors: Ponomarev D. , Hurley M. D. , Wallington T. J.
Published: August 2002

The kinetics of the reactions of F and C1 atoms with ethylene oxide have been studied using relative rate techniques in 10–700 Torr of either nitrogen or air diluent at 295 ± 2 K; k(F + C2H4O) = (9.4 ± 1.6) × 10−11 and k(C1 + C2H4O) = (5.0 ± 0.9) × 10−12 cm3 molecule−1 s−1. The result for k(F + C2H4O) is in good agreement with the literature data. The result for k(C1 + C2H4O) is a factor of 5.6 lower than that reported previously. It seems likely that in the previous study most of the loss of C2H4O attributed to reaction with C1 atoms was actually caused by unwanted secondary reactions leading to an overestimate of k(C1 + C2H4O). © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 122–125, 2002
Kinetics of destruction of diisopropyl methylphosphonate in corona discharge
Authors: Korobeinichev Oleg P. , Chernov Anatoly A. , Sokolov Vladimir V. , Krasnoperov Lev N.
Published: August 2002

The kinetics of the destruction of diisopropyl methylphosphonate (DIMP) in corona discharge has been studied using a flow tubular coaxial wire dielectric barrier corona discharge reactor. The identification and quantitative determination of DIMP, its destruction intermediates, and phosphorus‐containing destruction products were performed using molecular beam mass spectrometry and gas chromatography/mass spectrometry. Active discharge power was varied in the range 0.01–5 W. The destruction products such as isopropyl methylphosphonate, methylphosphonic acid, and orthophosphoric acid were found on the reactor walls. The dependence of the extent of the destruction, D (D = 1 − X / X0, where X and X0 are DIMP mole fractions at the outlet and the inlet of the reactor), on the specific energy deposition Ex (Ex = PF−1 X0−1, where F is the carrier gas flow and P is the power dissipated in discharge reactor) was measured over the DIMP mole fraction range 60–500 ppm at the pressure of 1 bar and the temperature of 340 K. Over the range of the experimental conditions studied the destruction obeys the “pseudo‐first‐order” kinetic law: ln(1 − D) = −KEx. Plausible mechanisms of the destruction are discussed. It was concluded that ion mechanism is the major one responsible for the destruction process. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 331–337, 2002
Structure‐reactivity correlation in the aminolysis of 4‐fluorophenyl acetate in aqueous medium
Authors: Rajarathnam D. , Jeyakumar T. , Nadar P. Ananthakrishna
Published: August 2002

The reaction of the title substrate with a series of amines of varying pKa, viz. ammonia, ethanolamine, glycine, 1,2‐diaminopropane, 1,3‐diaminopropane, n‐butylamine, piperidine, hydrazine, imidazole, and hydroxylamine is subjected to a kinetic study in aqueous medium, 25°C, ionic strength 0.1 M (KCl). Pseudo‐first‐order rate coefficients (kobs) are found throughout under amine excess at various pH values for each amine. For amines, excluding hydrazine, ammonia, and hydroxylamine the reaction follows clean second‐order kinetics and the plots of (kobs − kH) against free amine concentration are linear at constant pH. The macroscopic nucleophilic substitution rate coefficients (kN) are obtained as the slopes of these plots and found to be pH independent. For hydrazine, ammonia, and hydroxylamine, a rate dependence on more than first power of the amine is observed, accordingly, the rate constants for the assisted paths have been disseminated for these amines besides kN. The Brönsted‐type plot (logkN against amine pKa) is linear with a slope value of β = 1.02. The magnitude of the slope value is consistent with a stepwise mechanism through a zwitterionic tetrahedral addition intermediate whose breakdown to products is rate‐determining (k2 step). A remarkable reactivity difference is observed among the diamines, the reason for which is discussed in detail. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 366–373, 2002
Rally racing: knowledge and learning requirements for a winning team
Authors: Andreu Rafael , Sieber Sandra
Published: August 2002

In this paper we discuss how a winning rally racing team was developed from scratch in Seat Sport, the racing division within Seat, one of Volkswagen's divisions, which decided to enter the World Rally Cup in 1995. The discussion focuses on how different types of knowledge were literally ‘grown up’ from practically nothing to a winning team. We start by describing the knowledge requirements stemming from the goal of developing a World Rally Cup winning team. Defining them in the form of success factors, we classify them from different standpoints (explicit versus implicit, individual versus collective, mental models, coordination schemes, etc.). Next, we show how these different knowledge requirements were acquired and developed at Seat Sport. Finally, we derive the actual learning processes that were present at Seat Sport and relate them to the different kinds of needs and requirements. Copyright © 2001 John Wiley & Sons, Ltd.
Virtual organization: conceptual analysis of the limits of its decentralization
Authors: Kotorov Radoslav P.
Published: August 2002

The development of computer networks has reopened the discussion about the boundaries of the firm. Buy versus make decisions determine how centralized or decentralized a firm is. However, no consistent methodology has been proposed to help managers make these decisions. In this paper I shall propose a theoretical model of the firm, which is based on the assumption that every firm confronts competitive uncertainty and that its continual existence depends on its ability to reduce it, and based on this model I shall propose a method for organizational design. In the final section I shall analyze whether Ford's Business 2000 model corresponds to the model presented in this paper. Copyright © 2001 John Wiley & Sons, Ltd.
Case study of the application of BPR in an SME contractor
Authors: Riley M. J. , Brown D. C.
Published: August 2002

The UK government strongly encouraged the construction industry to improve its efficiency during the 1990s. P Trant Limited, a medium‐sized civil engineering contractor located in the south of England took on board this challenge and carried out a Business Process Re‐engineering programme. This paper describes the process modelling tools used, the re‐engineered processes and the efficiency gains produced. It is shown that mature medium‐sized contracting companies can benefit from undertaking such a change programme and that the benefits are not restricted to large companies or groups. Copyright © 2001 John Wiley & Sons, Ltd.
Experimental model for the long‐term effects of laser resurfacing
Authors: Babovic Srdan , Trevino Melanie Triffet , Petty Paul M.
Published: August 2002

Background and Objective

Evaluation of the long‐term effects of the laser resurfacing on development of the skin cancer after chronic ultraviolet B light exposure calls for the development of the appropriate animal model.

Study Design/Materials and Methods

The 27 C3H nu/nu nude mice were used in the experiment. Five experimental groups were designed to evaluate the effects of laser energy delivered.

Results

Tru‐Pulse™ Laser System produced char‐free crust immediately after application. There was no histologic difference in laser effects on the skin between groups. Complete re‐epithelialization occurred within 7 days.

Conclusions

An entire lifetime in this mammal model can be studied in under 2.5 years. The back skin of the mice can be resurfaced by using one pass 500 mJ/cm2 and complete healing will occur within a 7‐day period. We believe that establishment of this experimental model has set the stage for the further study of the effect of laser energy on sun‐damaged skin. Carbon dioxide laser resurfacing has become an increasingly popular method of facial rejuvenation, allowing the plastic surgeon to repair sun‐damaged skin and wrinkles. Results obtained by laser resurfacing seem to be long lasting. Carbon dioxide laser resurfacing brings about histologic changes in the skin. This finding raises a new question: Does carbon dioxide laser skin resurfacing modulate the effects of ultraviolet (UV) light exposure on the skin? The purpose of this study was to establish a new experimental model for studying the long‐term effects of laser skin resurfacing. Lasers Surg. Med. 28:138–140, 2001. © 2001 Wiley‐Liss, Inc.
Excimer laser (308 nm) based transmyocardial laser revascularization: Effects of the lasing parameters on myocardial histology
Authors: Shehada R.E.N. , Papaioannou T. , Mansour H.N. , Grundfest W.S.
Published: August 2002

Background and Objective

The effect of the excimer laser (308 nm) parameters on transmyocardial revascularization (TMR) channels is not well defined. This study investigates the influence of the pulse repetition rate, the size of the delivery catheter and its advancement speed on the morphology of TMR channels in vivo.

Study Design/Materials and Methods

Myocardial ablation was performed in a porcine model (N = 27) using multifiber catheters of 1.0 and 1.4 mm in diameter. The catheters were advanced into the myocardium at different speeds (1.27 and 2.54 mm/sec) while ablating at various repetition rates (10–;80 Hz). The radiant exposure was kept at 35 mJ/mm2 throughout the experiments. The channel histology was quantified by digital microscopy.

Results

The channel cross‐sectional area and the extent of the thermal damage decrease as the catheter advancement speed exceeds the ablation speed and vice versa. Within the parameters tested, advancement speed of about 1.3 mm/sec and pulse repetition rates of 40 Hz produce channels of size comparable to the catheter's diameter with moderate thermomechanical damage.

Conclusions

The repetition rate, catheter size, and catheter advancement speed are closely intertwined and crucial to the histological outcome of excimer laser based TMR. Lasers Surg. Med. 29:85–91, 2001. © 2001 Wiley‐Liss, Inc.
In vivo optical imaging of expression of vascular endothelial growth factor following laser incision in skin
Authors: Izzo Agnella D. , Mackanos Mark A. , Beckham Joshua T. , Jansen E. Duco
Published: August 2002

Background and Objective

Laser–tissue interaction studies have focused on laser‐induced secondary effects on tissue and the postmortem histological analysis of laser wounds. In this study we addressed wound healing and possible impairment of wound healing due to collateral tissue damage by in vivo imaging of gene expression.

Study Design/Materials and Methods

We used a transgenic mouse model containing a VEGF promoter driving a GFP reporter gene to image VEGF expression in vivo. Twenty‐two mice received two full thickness incisions in the dorsal skin: one with the Free Electron Laser (λ = 6.45 μm, 52.9 mJ/mm2) and one with a scalpel. Mice were imaged for GFP expression at 3 days, 1, 2, 3, and 4 weeks. Confocal microscopic imaging was performed at 2 weeks.

Results

Peak GFP expression was seen at 2–3 weeks and was localized in fibroblasts. FEL lesions showed more total GFP expression than scalpel lesions but this was only statistically significant (P < 0.05) at 2 and 4 weeks. The full‐width half‐max (FWHM) of the GFP expression was always larger for the FEL lesion compared to the scalpel lesion but was only statistically significant (P < 0.05) at 2 and 3 weeks. At 2 weeks the extent of the GFP expression in the laser lesion was on average 55 μm beyond that seen in the scalpel lesion but correlated with the number of laser passes.

Conclusions

Feasibility of using transgenic mice carrying photoactive reporter genes for studying cellular process of laser‐inflicted wound repair in a noninvasive, in vivo manner was shown. GFP expression mediated by the VEGF promoter in fibroblast showed minimal impairment of wound healing due to the laser. Lasers Surg. Med. 29:343–350, 2001. © 2001 Wiley‐Liss, Inc.
Mutations in conserved regions 1, 2, and 3 of Raf‐1 that activate transforming activity
Authors: Chan Edmond Y. W. , Stang Stacey L. , Bottorff Drell A. , Stone James C.
Published: August 2002

To investigate the role of Raf‐1 in v‐Ha‐ras transformation, we have isolated and characterized a number of Raf‐1 mutants that display increased transforming activity in Rat2 fibroblasts. A dipeptide deletion (Δ144–145) in the cysteine‐rich domain (CRD) of conserved region (CR) 1 increased the interaction between Raf‐1 and v‐Ha‐ras effector loop mutants in the yeast two‐hybrid system, supporting the proposal that the CRD serves as a secondary ras‐binding domain. Many activating mutations were located in CR2. Two representative CR2 mutants (Δ250–258 and S257L) displayed increased interaction with v‐Ha‐ras effector loop mutants and with mitogen‐activated protein kinase/extracellular signal–regulated kinase (ERK) kinase (MEK) 1 in the two‐hybrid system. One novel mutation in CR3 was recovered; G361S affected the third glycine of the GXGXXG protein kinase motif involved in ATP binding. Expression of G361S Raf‐1 in Rat2 fibroblasts activated MEK and ERK. The CR1, CR2, and CR3 activating mutations, when combined in cis, cooperated in transforming Rat2 fibroblasts. Conversely, Raf‐1 transforming activity was decreased when the S257L or G361S mutation was combined in cis with the R89E substitution, which disrupts ras‐Raf interaction. This mutant analysis provides additional information about the distinct functions of individual Raf‐1 regions and documents a novel genetic mechanism for activating an oncogenic kinase. © 2002 Wiley‐Liss, Inc.
A mutation in subunit B of the DNA polymerase α–primase complex from Novikoff hepatoma cells concomitant with a conformational change and abnormal catalytic properties of the DNA polymerase α–primase complex
Authors: Popanda Odilia , Flohr Claudia , Dai Jia‐Chun , Hunzicker Andreas , Thielmann Heinz Walter
Published: August 2002

Mutated constituents of the DNA replication complex might contribute to the mutational load of the genome during tumor development by impairing DNA synthesis as well as cell cycle–related control of DNA replication. To prove or disprove this hypothesis, we looked for mutations in the cDNA sequences of the four subunits of DNA polymerase α–primase from both highly malignant Novikoff hepatoma cells and regenerating normal rat liver and compared physicochemical and catalytic properties of the DNA polymerase α–primase complexes purified from both sources. Sequence analysis showed two mutations in subunit B from Novikoff cells: one in nucleotide position 855 (CCG→CCA) that did not result in an amino acid exchange and one in position 862 (GTG→ATG) that caused a change of valine to methionine in codon 288. No mutation was found in the three other subunits. The wild‐type and mutated sequences of subunit B were cloned and expressed in vitro. Sedimentation analysis of the expressed polypeptides revealed different sedimentation constants, indicating that the amino acid exchange affected the conformation of subunit B. The analysis of the purified DNA polymerase α–primase complexes showed a sedimentation value that was significantly higher for the enzyme complex from normal liver than for that from Novikoff cells. In addition, DNA polymerase α–primase complexes from Novikoff cells showed higher sensitivity to camptothecin, topotecan, and structurally related compounds (such as (R,S)‐7‐ethyl‐10‐hydroxy camptothecin, 9‐aminocamptothecin, and 10‐hydroxycamptothecin) than the enzyme from normal rat liver. Thus, the amino acid change found in subunit B appears to result in a conformational change of the DNA polymerase α–primase complex from Novikoff hepatoma cells. Whether this mutation influences genetic instability or tumor development needs to be explored. © 2001 Wiley‐Liss, Inc.
Design considerations for rapid‐heating columns applied in fast capillary gas chromatography
Authors: Van Deursen Marieke , Janssen Hans‐Gerd , Beens Jan , Rutten Gerard , Cramers Carel
Published: August 2002

Numerical calculation procedures are developed to predict the optimum experimental conditions for rapid‐programming fast capillary gas chromatography (GC). Retention times and peak widths are calculated from experimentally determined thermodynamic compound properties. Errors in the predicted values are below 2 and 15% for the retention times and peak widths, respectively. It is shown that rapid temperature programming is a powerful tool for speeding up the separation of samples containing homologous series of compounds such as, e.g., triglycerides. The optimal programming rate and the minimum required column length to obtain the shortest possible analysis time with sufficient resolution (Rs=1.5) are predicted. Using a wide‐bore column with a length of 10 m, a programming rate of 4°C/s and a carrier gas velocity of approximately 250 cm/s, the shortest possible analysis time for a triglycerides sample can be obtained while still maintaining sufficient resolution. With these instrumental settings the analysis time of a triglycerides separation can be reduced from 15 to approximately 5 minutes. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 337–345, 2001
Mathematical representation of electrophoretic mobility in mixed aqueous‐methanolic buffers in capillary zone electrophoresis
Authors: Jouybana A. , Chan H. K. , Clark B. J. , Kenndler E.
Published: August 2002

In a drug development program improved speed of the development phase is constantly being explored. But much effort and time is usually expended in finding suitable methods for pharmaceutical and biomedical analyses. In contrast, a mathematical model has been presented here to correlate/predict electrophoretic mobility of acidic and basic analytes in capillary electrophoresis at different concentrations of organic modifier. This model could help analysts to find the optimum concentration of organic modifier for a successful analysis. The accuracy and predictability of the proposed model have been shown using generated mobility data (five basic drugs in water‐methanol mixed running buffer) and previously published data sets collected from a recent publication. Using this model the average percentage errors for correlative and predictive equations were 0.64 and 1.35%, respectively. The accuracy of the model was also examined against those of previously published models where the results are comparable. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 346–350, 2001
Woman with facial spasm induced exclusively by sound
Authors: Stenager Egon , Binzer Michael
Published: August 2002

A woman is described in whom facial spasm occurs solely and predictably in the presence of certain noises. The symptoms resolve promptly as soon as the auditory stimulus stops. © 2002 Movement Disorder Society.
Phenotypic characterisation of autosomal recessive PARK6‐linked parkinsonism in three unrelated Italian families
Authors: Bentivoglio Anna R. , Cortelli Pietro , Valente Enza M. , Ialongo Tàmara , Ferraris Alessandro , Elia Antonio , Montagna Pasquale , Albanese Alberto
Published: August 2002

The clinical features of nine patients (three women and six men) affected by PARK6‐linked parkinsonism, belonging to three unrelated Italian families, are reported. The occurrence of affected men and women within one generation suggested an autosomal recessive mode of inheritance in all three families. Mean age at disease onset was 36 ± 4.6 years; all cases except one presented with asymmetrical signs, consisting of tremor and akinesia of one upper limb or unilateral short step gait. Affected individuals had a mean age of 57 ± 8.5 years, and average disease duration was 21 ± 7.8 years. Parkinsonian features included benign course, early onset of drug‐induced dyskinesias, and a good and persistent response to levodopa. There were no other associated features (i.e., pyramidal or cerebellar signs, dysautonomia, or diurnal fluctuations unrelated to drug treatment). Cognition was unaffected. The clinical picture was remarkably similar in all patients; no relevant family‐related differences were found. PARK6 disease is a new form of early‐onset parkinsonism without other atypical clinical features. © 2001 Movement Disorder Society.
Bilaterally coherent tremor resembling enhanced physiological tremor: Report of three cases
Authors: O'Sullivan John D. , Rothwell John , Lees Andrew J. , Brown Peter
Published: August 2002

The contribution of the central nervous system to tremor pathogenesis is unclear. Poor side‐to‐side coherence in physiological, essential, and parkinsonian tremors suggests distinct bilateral generators. By contrast, significant bilateral coherence demonstrated in orthostatic tremor and in enhanced physiological tremor (EPT) in patients with persistent mirror movements favours single or closely linked bilateral oscillators. We describe three patients (aged 21–37 years) who developed unusual bilateral postural and kinetic tremors at 6–13 Hz resembling EPT. The tremor involved all limbs, and in two cases the face or jaw, in the absence of other significant neurological features. Significant side‐to‐side coherence was demonstrated in each case using cross‐correlation of electromyographic recordings from homologous muscle pairs. We postulate that these unusual tremors originate from a single brainstem source or from bilateral oscillators closely linked at or below this level. © 2002 Movement Disorder Society