bluuebunny/crossref_metadata_2025 huggingface dataset:
NMR nomenclature: nuclear spin properties and conventions for chemical shifts. IUPAC Recommendations 2001. International Union of Pure and Applied Chemistry. Physical Chemistry Division. Commission on Molecular Structure and Spectroscopy
Authors: Harris Robin K. , Becker Edwin D. , Cabral de Menezes Sonia M. , Goodfellow Robin , Granger Pierre
Published: August 2002

An Addendum has been published for this article in Magnetic Resonance in Chemistry 40(9) 2002, 622.

A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1H resonance of tetramethylsilane. The unified scale is designed to provide a precise ratio, Ξ, of the resonance frequency of a given nuclide to that of the primary reference, the 1H resonance of tetramethylsilane (TMS) in dilute solution (volume fraction, ϕ < 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples, and values of Ξ for secondary references on the unified scale are listed, many of which are the results of new measurements. Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, δ, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic‐angle spinning. In all, nine new recommendations relating to chemical shifts are made. Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with non‐zero quantum numbers. The information given includes quantum numbers, isotopic abundances, magnetic moments, magnetogyric ratios and receptivities, together with quadrupole moments and linewidth factors (where appropriate). Copyright 2001 IUPAC. Reprinted with permission from Pure Appl. Chem. 2001; 73: 1795.
Use of 19F NMR spectroscopy to probe enzymatic oxidation of fluorine‐tagged sulfides
Authors: Behrouzian Behnaz , Hodgson Derek , Savile Christopher K. , Dawson Brian , Buist Peter H. , Shanklin John
Published: August 2002

A novel 19F NMR‐based method for monitoring the enzymatic oxidation of thia fatty acid analogues is presented. Our approach is based on the observation that methyl ω‐monofluorinated 9‐thia‐ and 10‐thiaoctadecanoates and their S‐oxide and S‐dioxide derivatives are easily distinguishable via their 1H‐decoupled 19F spectra. These long‐range substituent effects were used to probe the regio‐ and chemoselectivity of stearoyl ACP (acyl carrier protein) Δ9 desaturase‐mediated sulfoxidation. The results clearly demonstrate that mono‐oxygenation of a 10‐thia analogue ACP Δ9 desaturase was more efficient than that of a 9‐thia substrate. A product previously undetected by TLC was observed for the first time in the product mixture obtained from 18‐fluoro‐9‐thiaoctadecanoyl‐ACP. Copyright © 2002 John Wiley & Sons, Ltd.
NMR analysis of a series of photochromic pyranocarbazoles
Authors: Manuel Oliveira M. , Carvalho Luis M. , Moustrou Corinne , Samat André , Guglielmetti Robert , Oliveira‐Campos Ana M. F.
Published: August 2002

The study of the 1H and 13C resonance spectra of a series of 13 photochromic pyranocarbazoles was carried out using two‐dimensional methods. 1H and 13C resonances were deduced from the concerted application of HSQC, HMBC and DEPT experiments. Copyright © 2001 John Wiley & Sons, Ltd.
Biogenesis of lysosomes in marshall cells and in cells of the male reproductive system*
Authors: Morales C.R. , Fuska J. , Zhao Q. , Lefrancois S.
Published: August 2002

The mechanism of plasma membrane trafficking and degradation is still poorly understood. This investigation deals with the biogenesis of lysosomes during endocytic flow in Marshall cells and in various cell types of the male reproductive system. Marshall cells were exposed to ammonium chloride (NH4Cl) and leupeptin after labeling with cationic ferritin. In some experiments, the treated cells were immunogold labeled with anti‐prosaposin antibody. NH4Cl and leupeptin are lysosomotropic agents that affect the endosomal‐lysosomal progression. Testes, efferent ducts and epididymis from mouse mutants with defects affecting plasma membrane degradation were also used to analyze this process. NH4Cl produced a retention of cationic ferritin in endosomes and hindered the endosomal/lysosomal progression. Leupeptin did not affect this process. NH4Cl decreased the labeling of prosaposin in endosomes and lysosomes, while leupeptin increased the labeling of prosaposin in lysosomes. The number of lysosomes per cytoplasmic area was higher in treated cells than in controls. These findings suggest that leupeptin affected lysosomes whereas NH4Cl affected both endosomes and lysosomes. The endosomal and lysosomal accumulation of prosaposin induced by the treatment with NH4Cl and leupeptin indicated that the site of entry of prosaposinwas both the lysosome and endosome. Electron microscopy (EM) of tissues from mouse mutants with defects affecting plasma membrane degradation substantiated these observations. The EM analysis revealed a selective accumulation of multivesicular bodies (MVBs) and the disappearance of lysosomes, in testicular fibroblasts, nonciliated cells of the efferent ducts and principal cells of the epididymis, suggesting that MVBs are precursors of lysosomes. In conclusion: (1) endosomes and MVBs are a required steps for degradation of membranes; (2) endosomes and MVBs are precursors of lysosomes; and (3) endosomes, MVBs, and lysosomes appear to be transient organelles. Mol. Reprod. Dev. 59:54–66, 2001. © 2001 Wiley‐Liss, Inc.
Consequences of bovine oocyte maturation, fertilization or early embryo development in vitro versus in vivo: Implications for blastocyst yield and blastocyst quality
Authors: Rizos Dimitrios , Ward Fabian , Duffy Pat , Boland Maurice P. , Lonergan Patrick
Published: August 2002

The aim of this study is to examine the effect of bovine oocyte maturation, fertilization or culture in vivo or in vitro on the proportion of oocytes reaching the blastocyst stage, and on blastocyst quality as measured by survival following vitrification. In Experiment 1, 4 groups of oocytes were used: (1) immature oocytes from 2–6 mm follicles; (2) immature oocytes from > 6 mm follicles; (3) immature oocytes recovered in vivo just before the LH surge; and (4) in vivo matured oocytes. Significantly more blastocysts developed from oocytes matured in vivo than those recovered just before the LH surge or than oocytes from 2–6 mm follicles. Results from > 6 mm follicles were intermediate. All blastocysts had low survival following vitrification. In Experiment 2, in vivo matured oocytes were either (1) fertilized in vitro or (2) fertilized in vivo by artificial insemination and the resulting presumptive zygotes recovered on day 1. Both groups were then cultured in vitro. In vivo fertilized oocytes had a significantly higher blastocyst yield than those fertilized in vitro. Blastocyst quality was similar between the groups. Both groups had low survival following vitrification. In Experiment 3a, presumptive zygotes produced by in vitro maturation (IVM)/fertilization (IVF) were cultured either in vitro in synthetic oviduct fluid, or in vivo in the ewe oviduct. In Experiment 3b, in vivo matured/in vivo fertilized zygotes were either surgically recovered on day 1 and cultured in vitro in synthetic oviduct fluid, or were nonsurgically recovered on day 7. There was no difference in blastocyst yields between groups of zygotes originating from the same source (in vivo or in vitro fertilization) irrespective of whether culture took place in vivo or in vitro. However, there was a dramatic effect on blastocyst quality with those blastocysts produced following in vivo culture surviving vitrification at significantly higher rates than their in vitro cultured counterparts. Collectively, these results indicate that the intrinsic quality of the oocyte is the main factor affecting blastocyst yields, while the conditions of embryo culture have a crucial role in determining blastocyst quality. Mol. Reprod. Dev. 61: 234–248, 2002. © 2002 Wiley‐Liss, Inc.
Intrauterine infection and prematurity
Authors: Gonçalves Luís F. , Chaiworapongsa Tinnakorn , Romero Roberto
Published: August 2002

Intrauterine infection is a major cause of premature labor with and without intact membranes. Intrauterine infection is present in approximately 25% of all preterm births and the earlier the gestational age at delivery, the higher the frequency of intra‐amniotic infection. Microorganisms may also gain access to the fetus before delivery. A fetal inflammatory response syndrome elicited in response to microbial products is associated with the impending onset of preterm labor and also with multi‐systemic organ involvement in the human fetus and a higher rate of perinatal morbidity. The most common microorganisms involved in intrauterine infections are Ureaplasma urealyticum, Fusobacterium species and Mycoplasma hominis. The role of Chlamydia trachomatis and viruses in preterm labor remain to be determined. Use of molecular microbiology techniques to diagnose intrauterine infection may uncover the role of fastidious microorganisms that have not yet been discovered. Antibiotic administration to patients with asymptomatic bacteriuria is associated with a significant reduction in the rate of preterm birth. However, such benefit has not been demonstrated for patients with bacterial vaginosis, or women who carry Streptococcus agalactia, Ureaplasma urealyticum or Trichomonas vaginalis. Antibiotic administration to patients with preterm premature rupture of membranes is associated with prolongation of pregnancy and a reduction in the rate of clinical chorioamnionitis and neonatal sepsis. The benefit has not been demonstrated in patients with preterm labor and intact membranes. Major efforts are required to determine why some women develop an ascending intrauterine infection and others do not and also what interventions may reduce the deleterious effect of systemic fetal inflammation. MRDD Research Reviews 2002;8:3–13. © 2002 Wiley‐Liss, Inc.
Phase contrast MRI of myocardial 3D strain by encoding contiguous slices in a single shot
Authors: Reese Timothy G. , Feinberg David A. , Dou Jiangang , Wedeen Van J.
Published: August 2002

Quantitative measurements of inherently three‐dimensional (3D) cardiac strain and strain rate require 3D data; MRI provides uniquely high sensitivity to material strain by combining phase contrast with single‐shot acquisition methods, such as echo‐planar imaging (EPI). Previous MRI methods applied to 3D strain used multiple two‐dimensional (2D) acquisitions and suffered loss of sensitivity due to magnification within the strain calculation of physiologic noise related to cardiac beat‐to‐beat variability. In the present work, each single‐shot acquisition generates 3D image data by acquiring two contiguous 2D Fourier transform (FT) images in a single echo train of an EPI readout. Although strain encoding divides across multiple EPI shots, each strain component is computed only within single‐shot data, avoiding noise magnification. Strain tensor maps are displayed using iconic 3D graphics or a simple color code of tensor shape. In a deforming gel phantom, gradient‐recalled echo (GRE) MRI movies of 3D strain rates match expected strain fields. In normal human subjects, 3D strain rate tensor movies of heart and brain comprising seven slices in each of seven cardiac phases were completed in 56 heartbeats. Stimulated echo (STE) MRI of net systolic 3D strain was also demonstrated. Two‐slices‐in‐one‐shot spatial encoding permits a complete quantitative survey of ventricular 3D strain in under a minute, with routine patient supervision and turnkey image processing. Magn Reson Med 47:665–676, 2002. © 2002 Wiley‐Liss, Inc.
High‐resolution blood flow velocity measurements in the human finger
Authors: Klarhöfer M. , Csapo B. , Balassy Cs. , Szeles J.C. , Moser E.
Published: August 2002

MR phase contrast blood flow velocity measurements in the human index finger were performed with triggered, nontriggered, and cine acquisition schemes. A strong (Gmax = 200 mT/m), small bore (inner diameter 12 cm) gradient system inserted in a whole body 3 Tesla MR scanner allowed high‐resolution imaging at short echo times, which decreases partial volume effects and flow artifacts. Arterial blood flow velocities ranging from 4.9–19 cm/sec were measured, while venous blood flow was significantly slower at 1.5–7.1 cm/sec. Taking into account the corresponding vessel diameters ranging from 800 μm to 1.8 mm, blood flow rates of 3.0–26 ml/min in arteries and 1.2–4.8 ml/min in veins are obtained. The results were compared to ultrasound measurements, resulting in comparable blood flow velocities in the same subjects. Magn Reson Med 45:716–719, 2001. © 2001 Wiley‐Liss, Inc.
High‐resolution 1H NMR spectroscopy in organs and tissues using slow magic angle spinning
Authors: Wind Robert A. , Hu Jian Zhi , Rommereim Donald N.
Published: August 2002

It is shown that high‐resolution 1H NMR spectra of intact excised tissues and organs can be obtained by rotating the sample slowly about an axis at the magic angle of 54°44′ with the external magnetic field. In this way tissue and cellular damage invoked by standard magic angle spinning (MAS) experiments, where spinning speeds of several kHz are typically employed, are minimized. Special RF pulse sequences, developed originally in solid state NMR, can be used to produce a spinning sideband‐free isotropic spectrum. In this article the first results are shown of the brain, heart, liver, gluteus muscle, and kidney excised from mice using the 2D‐phase‐altered spinning sidebands (PASS) technique and employing MAS spinning speeds of 43–125 Hz. It was found that with slow sample spinning similar, and in some cases even better, spectral resolutions are obtained as compared with fast MAS. Magn Reson Med 46:88–94, 2001. Published 2001 Wiley‐Liss, Inc.
Simple methods for the correction of T2 maps of phantoms
Authors: Lepage M. , Tofts P.S. , Bäck S.Å.J. , Jayasekera P.M. , Baldock C.
Published: August 2002

Two simple methodologies for correcting the errors in T2 maps for phantom measurements are presented; they both give accurate MRI maps with a low coefficient of variation (CV). The rate correction method is based on an equation relating the true T2 (T2,t) and that determined experimentally (T2,exp) for homogenous phantoms. The response matrix method is a phenomenological analysis of the difference between T2,exp and T2,t, from which correction factors are computed for a range of T2 values and for every pixel of an image. The factors were obtained from phantoms filled with a homogeneous gelatin gel and having different T2,t values. The CV in homogeneous phantom measurements were reduced from 2.5–4.0% to approximately 0.6–2.0% for T2,t values ranging from 180–600 ms. Examples are shown for the correction of T2 maps of phantoms filled with polymer dosimeter gel irradiated with photon beams from a linear accelerator. The methodologies presented can easily be implemented on a clinical MRI scanner. Magn Reson Med 46:1123–1129, 2001. © 2001 Wiley‐Liss, Inc.
Inhibition of the initial wave of NF‐κB activity in rat muscle reduces ischemia/reperfusion injury
Authors: Lille Sean T. , Lefler Scott R. , Mowlavi Arian , Suchy Hans , Boyle Edward M. , Farr Angela L. , Su Chen‐Yuan , Frank Norbert , Mulligan David C.
Published: August 2002

Nuclear factor kappaB (NF‐κB) is thought to play an important role in the expression of genes expressed in response to ischemia/reperfusion (I/R) injury. In this report, the activation of NF‐κB in rat skeletal muscle during reperfusion following a 4‐h ischemic period was studied. NF‐κB activation displayed a biphasic pattern, showing peak activities from 30 min to 3 h postperfusion and 6 h to 16 h postperfusion, with a decline to baseline binding activity levels between 3 h and 6 h. Inhibition of NF‐κB activation was investigated using proline dithiocarbamate (Pro‐DTC). NF‐κB binding activity during reperfusion was significantly reduced by intravenous administration of Pro‐DTC. Additionally, Pro‐DTC resulted in decreased muscle edema and neutrophil activity, with an increased percentage of muscle survival compared with vehicle controls. These results demonstrate that NF‐κB is activated during reperfusion in a biphasic manner and that the regulation of the initial phase of NF‐κB activation affords physiological protection against a severe ischemic stress. Selective inhibition of NF‐κB during early reperfusion may therefore be a therapeutic intervention for I/R injury. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 534–541, 2001
Real‐scale miscible grout injection experiment and performance of advection–dispersion–filtration model
Authors: Bouchelaghem F. , Vulliet L. , Leroy D. , Laloui L. , Descoeudres F.
Published: August 2002

A model was developed, to describe miscible grout propagation in a saturated deformable porous medium, based on Bear's statistical model with spatial volume averaging. In a previous paper, the model was first successfully confronted to one‐dimensional laboratory experiments.

In the present paper, the numerical model is used to simulate practical grouting operation in a cylindrical injection model. The cylindrical injection model lends itself to study main flow and propagation character istics for a dispersed suspension‐type grout, under axisymmetric conditions close to real scale conditions.

Comparison between numerical solutions and experimental results is essential to confirm the validity and accuracy of the proposed model from a phenomenological standpoint. The numerical model performances show that the underlying mathematical model constitutes a realistic predictive model reproducing most prominent features during injection of a suspension‐type grout into a deformable porous medium. The basic mechanism by which injected miscible grout permeates a soil mass is discussed in detail. Such a tool leads to quality control criteria for grouting on a theoretical basis, which complements existing criteria acquired through engineering practice. Copyright © 2001 John Wiley & Sons, Ltd.
Self‐similar solution of a plane‐strain fracture driven by a power‐law fluid
Authors: Adachi J. I. , Detournay E.
Published: August 2002

This paper analyses the problem of a hydraulically driven fracture, propagating in an impermeable, linear elastic medium. The fracture is driven by injection of an incompressible, viscous fluid with power‐law rheology and behaviour index n⩾0. The opening of the fracture and the internal fluid pressure are related through the elastic singular integral equation, and the flow of fluid inside the crack is modelled using the lubrication theory. Under the additional assumptions of negligible toughness and no lag between the fluid front and the crack tip, the problem is reduced to self‐similar form. A solution that describes the crack length evolution, the fracture opening, the net fluid pressure and the fluid flow rate inside the crack is presented. This self‐similar solution is obtained by expanding the fracture opening in a series of Gegenbauer polynomials, with the series coefficients calculated using a numerical minimization procedure. The influence of the fluid index n in the crack propagation is also analysed. Copyright © 2002 John Wiley & Sons, Ltd.
Involuntary detrusor contractions: Correlation of urodynamic data to clinical categories
Authors: Romanzi Lauri J. , Groutz Asnat , Heritz Dianne M. , Blaivas Jerry G.
Published: August 2002

Data regarding the prevalence and urodynamic characteristics of involuntary detrusor contractions (IDC) in various clinical settings, as well as in neurologically intact vs. neurologically impaired patients, are scarce. The aim of our study was to evaluate whether the urodynamic characteristics of IDC differ in various clinical categories. One hundred eleven consecutive neurologically intact patients and 21 consecutive neurologically impaired patients, referred for evaluation of persistent irritative voiding symptoms, were prospectively enrolled. All patients were presumed by history to have IDC, and underwent detailed clinical and urodynamic evaluation. Based on clinical evaluation, patients were placed into one of four categories according to the main presenting symptoms and the existence of neurological insult: 1) frequency/urgency; 2) urge incontinence; 3) mixed stress incontinence and irritative symptoms; and 4) neurogenic bladder. IDC was defined by detrusor pressure of ≥ 15 cm H2O whether or not the patient perceived the contraction; or < 15 cm H2O if perceived by the patient. Eight urodynamic characteristics of IDC were analyzed and compared between the four groups. IDC were observed in all of the neurologically impaired patients, compared with 76% of the neurologically intact patients (P < 0.001). No correlation was found between amplitude of IDC and subjective report of urgency. All clinical categories demonstrated IDC at approximately 80% of cystometric capacity. Eighty‐one percent of the neurologically impaired patients, compared with 97% of the neurologically intact patients, were aware of the IDC at the time of urodynamics (P < 0.04). The ability to abort the IDC was significantly higher among continent patients with frequency/urgency (77%) compared with urge incontinent patients (46%) and neurologically impaired patients (38%). In conclusion, when evaluating detrusor overactivity, the characteristics of the IDC are not distinct enough to aid in differential diagnosis. However, the ability to abort IDC and stop incontinent flow may have prognostic implications, especially for the response to behavior modification, biofeedback, and pelvic floor exercise. Neurourol. Urodynam. 20:249–257, 2001. © 2001 Wiley‐Liss, Inc.
Urodynamic follow‐up of experimental urethral obstruction in individual guinea pigs
Authors: Wolffenbuttel K.P. , Kok D.J. , Minekus J.P.J. , van Koeveringe G.A. , van Mastrigt R. , Nijman J.M.
Published: August 2002

It is unknown whether changes in bladder function due to urethral obstruction follow a specific sequence. To answer this, we adapted a small animal model to allow repeated complete pressure‐flow studies, enabling individual follow‐up of changes in bladder function on urethral obstruction. Obstruction was induced in guinea pigs by placing a silver ring around the urethra. Urodynamic studies were repeated under anesthesia with ketamine/xylazine. Bladders were filled and bladder pressure measured through a single suprapubic catheter. Urine flow rate was measured using an ultrasound probe around the penis. Accurate measurements of bladder pressure and urine flow rates were obtained at 1‐week intervals for 11 weeks in individual guinea pigs. In the control animals, the urodynamic parameters did not show significant changes. In the obstructed group, urethral resistance (Plow,ave) increased from 20 to 35 cm H2O after 4 weeks and remained at that level. The maximum flow rate (Qmax) increased from 0.17 to 0.24 mL/s after 2 to 3 weeks. After this peak, it gradually decreased to lower than the starting value after 10 to 11 weeks. The pressure at maximum flow rate (pQmax) increased from 24 to 47 cm H2O after 6 to 7 weeks and thereafter declined. During weeks 1 through 4 of obstruction, unstable contractions were seen. All animals followed a similar sequence of patterns but at variable rates. Our animal model allows complete urodynamic follow‐up of individual animals with urethral obstruction. We observed a specific sequence of changes in urodynamic patterns and parameters of bladder function. Neurourol. Urodynam. 20:699–713, 2001. © 2001 Wiley‐Liss, Inc.
Physiologic bladder evacuation with selective sacral root stimulation: Sinusoidal signal and organ‐specific frequency
Authors: Sievert Karl‐Dietrich , Gleason Curtis A. , Jünemann Klaus‐Peter , Alken Peter , Tanagho Emil A.
Published: August 2002

In patients with spinal cord injury above S2, who characteristically have both detrusor hyperflexia and sphincteric spasm, sacral anterior root stimulation can evacuate the bladder, but sacral deafferentation is needed to eliminate the hyperreflexia for normal bladder filling. The common stimulation parameters for these patients activate the detrusor and the external urethral sphincter simultaneously (detrusor‐sphincter dyssynergia), and the resultant post‐stimulus voiding is not physiologic. We sought to determine organ‐specific stimulation parameters. In 20 male dogs, the rectangular pulse and sinusoidal signal forms were evaluated with a variety of parameters for stimulation of S2 and S3 anterior roots extra‐ and intradurally (i.e., stimulation frequency and voltage, uni‐ versus bilateral electrode placement, and degree of bladder filling). New torpedo‐shaped bipolar electrodes were used, adjusted to neural diameter. The best results were recorded with intradural bilateral sinusoidal signal. Sphincteric fatigue was produced by pre‐stimulating S2 with 104 ± 17 Hz and 0.8 ± 0.1 V for 10 to 15 seconds before S3 stimulation. S3 stimulation with 16 ±  2.1 Hz and 0.4 ± 0.1 V evoked a detrusor pressure of 28.7 ± 3.0 cm H2O above the sphincteric pressure. Selective anterior root stimulation with organ‐specific stimulation parameters can effect initial sphincteric fatigue to achieve physiologic voiding. Neurourol. Urodynam. 21:80–91, 2002. © 2002 Wiley‐Liss, Inc.
The organization of synaptic vesicles at tonically transmitting connections of locust visual interneurons
Authors: Leitinger Gerd , Simmons Peter J.
Published: August 2002

Large, second‐order neurons of locust ocelli, or L‐neurons, make some output connections that transmit small changes in membrane potential and can sustain transmission tonically. The synaptic connections are made from the axons of L‐neurons in the lateral ocellar tracts, and are characterized by bar‐shaped presynaptic densities and densely packed clouds of vesicles near to the cell membrane. A cloud of vesicles can extend much of the length of this synaptic zone, and there is no border between the vesicles that are associated with neighboring presynaptic densities. In some axons, presynaptic densities are associated with discrete small clusters of vesicles. Up to 6% of the volume of a length of axon in a synaptic zone can be occupied with a vesicle cloud, packed with 4.5 to 5.5 thousand vesicles per μm3. Presynaptic densities vary in length, from less than 70 nm to 1.5 μm, with shorter presynaptic densities being most frequent. The distribution of vesicles around short presynaptic densities was indistinguishable from that around long presynaptic densities, and vesicles were distributed in a similar way right along the length of a presynaptic density. Within the cytoplasm, vesicles are homogeneously distributed within a cloud. We found no differences in the distribution of vesicles in clouds between locusts that had been dark‐adapted and locusts that had been light‐adapted before fixation. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 93–105, 2002; DOI 10.1002/neu.10018
A survey of spectral factorization methods
Authors: Sayed A. H. , Kailath T.
Published: August 2002

Spectral factorization is a crucial step in the solution of linear quadratic estimation and control problems. It is no wonder that a variety of methods has been developed over the years for the computation of canonical spectral factors. This paper provides a survey of several of these methods with special emphasis on clarifying the connections that exist among them. While the discussion focuses primarily on scalar‐valued rational spectra, extensions to non‐rational and vector‐valued spectra are briefly noted. Copyright © 2001 John Wiley & Sons, Ltd.
The effect of overall discretization scheme on Jacobian structure, convergence rate, and solution accuracy within the local rectangular refinement method
Authors: Bennett Beth Anne V. , Smooke Mitchell D.
Published: August 2002

The local rectangular refinement (LRR) solution‐adaptive gridding method automatically produces orthogonal unstructured adaptive grids and incorporates multiple‐scale finite differences to discretize systems of elliptic governing partial differential equations (PDEs). The coupled non‐linear discretized equations are solved simultaneously via Newton's method with a Bi‐CGSTAB linear system solver. The grids' unstructured nature produces a nonstandard sparsity pattern within the Jacobian.

The effects of two discretization schemes (LRR multiple‐scale stencils and traditional single‐scale stencils) on Jacobian bandwidth, convergence speed, and solution accuracy are studied. With various point orderings, for two simple problems with analytical solutions, the LRR multiple‐scale stencils are seen to: (1) produce Jacobians of smaller bandwidths than those resulting from the traditional single‐scale stencils; (2) lead to significantly faster Newton's method convergence than the single‐scale stencils; and (3) produce more accurate solutions than the single‐scale stencils.

The LRR method, including the LRR multiple‐scale stencils, is finally applied to an engineering problem governed by strongly coupled, highly non‐linear PDEs: a steady‐state lean Bunsen flame with complex chemistry, multicomponent transport, and radiation modeling. Very good agreement is observed between the computed flame height and previously published experimental data. Copyright © 2001 John Wiley & Sons, Ltd.
An efficient high‐order algorithm for solving systems of reaction‐diffusion equations
Authors: Liao Wenyuan , Zhu Jianping , Khaliq Abdul Q.M.
Published: August 2002

An efficient higher‐order finite difference algorithm is presented in this article for solving systems of two‐dimensional reaction‐diffusion equations with nonlinear reaction terms. The method is fourth‐order accurate in both the temporal and spatial dimensions. It requires only a regular five‐point difference stencil similar to that used in the standard second‐order algorithm, such as the Crank‐Nicolson algorithm. The Padé approximation and Richardson extrapolation are used to achieve high‐order accuracy in the spatial and temporal dimensions, respectively. Numerical examples are presented to demonstrate the efficiency and accuracy of the new algorithm. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 340–354, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/num.10012
Modeling condom‐use stage of change in low‐income, single, urban women*
Authors: Morrison‐Beedy Dianne , Carey Michael P. , Lewis Brian P.
Published: August 2002

This study was undertaken to identify and test a model of the cognitive antecedents to condom use stage of change in low‐income, single, urban women. A convenience sample of 537 women (M=30 years old) attending two urban primary health care settings in western New York State anonymously completed questionnaires based primarily on two leading social‐cognitive models, the transtheoretical model and the information–motivation–behavioral skills model. We used structural equation modeling to examine the direct and indirect effects of HIV‐related knowledge, social norms of discussing HIV risk and prevention, familiarity with HIV‐infected persons, general readiness to change sexual behaviors, perceived vulnerability to HIV, and pros and cons of condom use on condom‐use stage of change. The results indicated two models that differ by partner type. Condom‐use stage of change in women with steady main partners was influenced most by social norms and the pros of condom use. Condom‐use stage of change in women with “other” types (multiple, casual, or new) of sexual partners was influenced by HIV‐related knowledge, general readiness to change sexual behaviors, and the pros of condom use. These findings suggest implications for developing gender‐relevant HIV‐prevention interventions. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:122–134, 2002
Intensity of case managers' participation in organizational decision making§
Authors: Issel L. Michele , Anderson Ruth A.
Published: August 2002

Prior research has indicated that registered nurse (RN) participation in decision making (PDM) is related to better outcomes in nursing homes and hospitals. Little is known, however, about the roles of community‐based case managers (CMs), most of whom are RNs. Data from 68 prenatal case management programs were used to test hypotheses about the intensity of CM PDM and to describe their patterns of involvement in decision activities and mechanisms. CMs were most involved in the activity of “raising the issue” and least involved in “choosing the alternative.” However, “choosing the alternative” was the strongest predictor of perceived CM influence over the final choice. When CMs were involved in informal meetings and chance encounters with administrators, they were more likely to be perceived as having influence over the final choices made. Intensity of CM PDM varied by decision level and content, supporting two of the three hypotheses. The findings are discussed in light of prior research and complexity theory. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:361–372, 2001
Improving cognitive development of low‐birth‐weight premature infants with the COPE program: A pilot study of the benefit of early NICU intervention with mothers
Authors: Melnyk Bernadette Mazurek , Alpert‐Gillis Linda , Feinstein Nancy Fischbeck , Fairbanks Eileen , Schultz‐Czarniak Jaclyn , Hust Diane , Sherman Laura , LeMoine Christine , Moldenhauer Zendi , Small Leigh , Bender Nancee , Sinkin, MD Robert A.
Published: August 2002

The purpose of this pilot study was to evaluate the effectiveness of a parent‐focused intervention program (COPE) on infant cognitive development and maternal coping. A randomized clinical trial was conducted with 42 mothers of low‐birth‐weight (LBW) premature infants hospitalized in a neonatal intensive care unit (NICU), with follow‐up at 3 months' and 6 months' corrected ages. COPE mothers received the four‐phase educational–behavioral program that began 2–4 days postbirth and continued through 1 week following discharge from the NICU. Comparison mothers received audiotaped information during the same four time frames. Results indicated that COPE infants had significantly higher mental development scores at a 3 months' corrected age (M = 100.3) than did the comparison infants (M = 93.9), and this difference widened at 6 months' corrected age, with COPE infants scoring 14 points higher. COPE mothers were significantly less stressed by the NICU sights and sounds and had significantly stronger beliefs about what behaviors and characteristics to expect from their premature infants. Findings from this study support the need for further testing of early NICU interventions with parents to determine their effectiveness on parental coping and infant developmental outcomes. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:373–389, 2001
The sustainability of resources used by Native Americans on four Caribbean islands
Authors: Wing Elizabeth S.
Published: August 2002

Changes in the subsistence economies during the 2000‐year colonization of the Leeward and Virgin islands are discussed. The colonists migrated from northern South America with traditions for producing ceramics, engaging in horticulture, fishing, gathering, and managing captive animals. Based on analysis of pairs of faunal samples from four islands, I am able to show some consistent changes in the relative abundances of some species, the sizes of individual animals, and the mean trophic levels of the aquatic components of the faunas. The changes that take place through time are: decline in the relative abundance of land crabs; a relative increase in the abundance of molluscs; decline in the mean trophic level of reef fishes; a subsequent increase or decrease in the mean trophic level of inshore and pelagic fishes. In those sites where the mean trophic level of inshore and pelagic fishes occurs it is dominated by tuna and other large predators, increased dependence upon herrings and other small fishes reduced the mean trophic level. These changes accompanied a human population increase and intensification of the horticultural enterprise. The root cause of many of these changes is overexploitation. Compensation for the decline in some resources is accomplished through changes in fishing technology. Copyright © 2001 John Wiley & Sons, Ltd.
Osteological features associated with ankle hyperdorsiflexion
Authors: Boulle Eve‐Line
Published: August 2002

The habitual adoption of certain gestures and postural habits can result in a variety of non‐metric traits, including supernumerary facets that are both articular and non‐articular. The squatting facet is a classical example of the former, and generally presents as a lateral articular facet on the neck of the talus that articulates with a facet on the anterior border of the distal tibia. These facets arise owing to the adoption of the squatting position and the hyperdorsiflexed position of the ankle joint, bringing the talus and tibia into immediate approximation. This study reports on the difference between the classical squatting facet and a non‐articular facet, which can also present on the neck of the talus but occurs, probably, as a result of soft tissue pressure, rather than bony articulation. It is suggested that whilst the function of the two facets may be similar, their aetiology is likely to be very different. Copyright © 2001 John Wiley & Sons, Ltd.
Car ownership and welfare‐to‐work
Authors: Ong Paul M.
Published: August 2002

This study examines the role of car ownership in facilitating employment among recipients under the current
welfare‐to‐work law. Because of a potential problem with simultaneity, the analysis uses predicted
car ownership constructed from two instrumental variables, insurance premiums and population density for car
ownership. The data come from a 1999–2000 survey of TANF recipients in the Los Angeles metropolitan area.
The empirical results show a significant independent contribution of car ownership on employment. The presence of
an predicted ownership is associated with a 9 percentage point increase in the odds of being employed. Moreover,
the results indicate that lowering insurance premiums by $100 can increase the odds of employment by 4
percentage points. © 2002 by the Association for Public Policy Analysis and Management.
Synthesis of polymethylmethacrylate in THF solution with phosphorous containing initiators
Authors: Poljans̆ek Ida
Published: August 2002

For the synthesis of polymethylmethacrylate, tetraphenyl biphosphine (TPhBP) with a thermally and photochemically unstable P‐P bond was employed. Under the influence of UV light, this bond split to two relatively stable biphenylphosphine radicals, which are able to react with the monomer. The resultant macroinitiators were isolated and were used for further polymerization with the same or another monomer to synthesize block‐copolymers.

Controlled polymerization of methyl methacrylate with tetraphenyl biphosphine took place in the absence of oxygen by UV irradiation in THF solution. For MMA alone an insignificant portion photo‐ (0.3%) and thermal‐ (2%) polymerization were detected. Using selected quantity of the initiator, macroinitiators with predicted molecular weight as well as block‐copolymers were synthesized.

The macroradicals were terminated by primary ‐PPh
2 radicals, by chain transfer to initiator and by the combination of two macroradicals. We determined chain end groups by nuclear magnetic resonance spectroscopy (NMR) and the relative molecular weights of the polymers by gel permeation chromatography (GPC). The molecular weights were calculated using the
1H NMR spectra from the ratio between the end groups signals and signals of the chain and were compared to GPC measurements. The calculated and observed molecular weights were in good agreement. At the lower concentration of initiator the molecular weight increased with conversion, while at the higher initiator concentration the molecular weight decreased with increasing conversion which could be ascribed to chain transfer to initiator. Copyright © 2001 John Wiley & Sons, Ltd.
Scale‐up synthesis of hyperbranched poly(amidoamine)‐grafted ultrafine silica using dendrimer synthesis methodology in solvent‐free dry‐system
Authors: Murota Masamichi , Sato Shimpei , Tsubokawa Norio
Published: August 2002

Scale‐up synthesis of hyperbranched poly(amidoamine)‐grafted ultrafine silica was successfully achieved by using dendrimer synthesis methodology in solvent‐free dry‐system. The poly(amidoamine) was allowed to grow from silica surface by repeating two steps: (1) Michael addition of methyl acrylate (MA) to amino group on the surface and (2) amidation of terminal ester group with ethylenediamine (EDA). MA was sprayed onto silica having amino group and the silica agitated at 300 rpm at 50 °C. After the reaction, unreacted MA was removed under vacuum. Then EDA was sprayed and the reaction was conducted at 50 °C with agitation. After the reaction, unreacted EDA was also removed under vacuum at 50 °C and MA was sprayed again. The percentage of poly(amidoamine) grafting onto the surface was determined to be 141% with repeated reaction cycles of eight‐times. However, the value was considerably smaller than that of the theoretical value. This indicates that the propagation of poly(amidoamine) dendron from silica surface was not achieved theoretically and hyperbranched poly(amidoamine) was grafted onto the surface because of steric hindrance of grafted polymer. In addition, the effect of initial amino group content on the growth of poly(amidoamine) from the surface was investigated. It was concluded that the method is suitable for the scale‐up synthesis of hyperbranched poly(amidoamine)‐grafted silica. Copyright © 2002 John Wiley & Sons, Ltd.
Studies on synthesis, characterization and adhesive strength evaluation of KFA substituted resole adhesives
Authors: Parija S. , Mohnaty A. K. , Misra M. , Nayak S. K. , Tripathy S. S.
Published: August 2002

Preliminary investigations revealed the presence of appreciable amount of gum rich in lignin and tannin in kendu fruit (Diospyros Cordifolia Roxb). The kendu fruit adhesive (KFA) was used to substitute phenol in resole formulations to achieve cost effectiveness. Substituted resole formulations with 50 and 100% KFA were prepared in alkaline medium through stepwise addition process. Unsubstituted and KFA substituted resole adhesives were then characterized by FT‐IR, thermogravimetric analysis, differential scanning calorimetry and X‐ray diffraction analysis. The adhesive strength of the above mentioned formulations were evaluated by comparing the results of mechanical tests as per the ASTM specifications using UTM‐LR‐100K LLOYD Instruments, UK. Analytical characterizations revealed the substitutions of phenol by KFA in the substituted resole formulations. The results of adhesive strength test revealed that the 50% KFA substituted PF resin exhibits better adhesive strength than the virgin phenol‐formaldehyde and 100% KFA‐formaldehyde resole formulation. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of 4,4′‐bis (4‐oxyphenoxy)benzophenone diglycidyl ether and the thermal stability for blends with 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexanecarboxylate
Authors: Hwang Seok‐Ho , Lee Guen‐Soo , Lee Kwan‐Ku , Jung Jae‐Chang
Published: August 2002

We synthesized novel aromatic epoxy, 4,4′‐bis(4‐oxyphenoxy)benzophenone diglycidyl ether (DGEEK), by a three step reaction sequence and then it was blended with 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexanecarboxylate (CAE). The DGEEK structure was confirmed by FT‐IR and 1H‐NMR measurement. Also, we investigated thermal properties of DGEEK/CAE blend epoxy by differential scanning calorimeter (DSC) and thermogravimetry analyzer (TGA). The glass transition temperature increased but initial decomposition temperature of cured epoxy decreased through the increasing amounts of ether–ether–ketone group of the epoxy network structure. By increasing the DGEEK mole fraction in the DGEEK/CAE blend epoxy matrix, the curing peak temperature decreased and the curing activation energy for DGEEK/CAE blend epoxy systems showed a considerable decrease. Copyright © 2001 John Wiley & Sons, Ltd.
Control of endothelial cell adhesion to polymer surface by ion implantation
Authors: Kusakabe M. , Suzuki Y. , Nakao A. , Kaibara M. , Iwaki M. , Scholl M.
Published: August 2002

The bio‐compatibility of ion implanted polymers has been studied by means of in vitro attachment measurements of bovine aorta endothelial cells. The specimens used were polystyrene (PS), polyethylene (PE), polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE). He+ and Ne+ ion implantation were performed at an energy of 150 keV with fluences between 1 × 10
13 to 1 × 10
17 ions/cm
2 at room temperature. Wettability was estimated by means of a sessile drop method. The chemical and physical structures of ion implanted polymers were investigated by contact angle measurements, atomic force microscopy and X‐ray photoelectron spectroscopic analysis in relation to cell attachment behavior. The strength of cell attachment on ion implanted specimens at static and under flow conditions was also measured. Ion implanted PP and ePTFE were found to exhibit remarkably higher adhesion and spreading of endothelial cells than non‐implanted specimens. In contrast to these findings, ion implanted PS and PE only demonstrated a little improvement of cell adhesion in this assay. Copyright © 2001 John Wiley & Sons, Ltd.
Differential expression of vesicular monoamine transporter (VMAT) 1 and 2 in gastrointestinal endocrine tumours
Authors: Jakobsen Anne‐Marie , Andersson Pernilla , Saglik Gulay , Andersson Ellinor , Kölby Lars , Erickson Jeffrey D. , Forssell‐Aronsson Eva , Wängberg Bo , Ahlman Håkan , Nilsson Ola
Published: August 2002

Neuroendocrine tumours are characterized by their capacity to produce hormones, which are stored in vesicles and secretory granules. Demonstration of granule/vesicle proteins in tumours is taken as evidence of neuroendocrine differentiation. Vesicular monoamine transporters (VMAT1 and VMAT2) mediate the transport of amines into vesicles of neurons and endocrine cells. The expression of VMAT1 and VMAT2 and the usefulness of VMAT1 and VMAT2 in the histopathological diagnosis of gastrointestinal endocrine tumours have not been fully explored. This study therefore investigated the expression of VMAT1 and VMAT2 in 211 human gastrointestinal tumours by immunocytochemistry and western blotting. VMAT1 and/or VMAT2 were demonstrated in the majority of amine‐producing endocrine tumours of gastric, ileal, and appendiceal origin. Serotonin‐producing endocrine tumours (ileal and appendiceal carcinoids) expressed predominantly VMAT1, while histamine‐producing endocrine tumours (gastric carcinoids) expressed VMAT2 almost exclusively. In peptide‐producing endocrine tumours such as rectal carcinoids and endocrine pancreatic tumours, only a small number of immunopositive tumour cells were observed. No labelling was found in non‐endocrine tumours, including gastric, colorectal and pancreatic adenocarcinomas and gastrointestinal stromal tumours. In conclusion, VMAT1 and VMAT2 are differentially expressed by gastrointestinal endocrine tumours, with a pattern specific for each tumour type, reflecting their neuroendocrine differentiation and origin. VMAT1 and VMAT2 may therefore become valuable markers in the classification of neuroendocrine tumours and may also indicate patients suitable for radioisotope treatment operating via these transporter systems. Copyright © 2001 John Wiley & Sons, Ltd.