bluuebunny/crossref_metadata_2025 huggingface dataset:
Compliant design of artificial graft: Compliance determination by new digital X‐ray imaging system‐based method
Authors: Sonoda Hiromichi , Urayama Shin‐Ichi , Takamizawa Keiichi , Nakayama Yasuhide , Uyama Chikao , Yasui Hisataka , Matsuda Takehisa
Published: August 2002

The development of an artificial graft requires formulation of biomechanical design criteria. The compliance of artifical grafts, based on the intraluminal pressure‐internal diameter (Pi‐Di) relationship, was measured by a novel method using a digital X‐ray imaging system coupled with an edge detection algorithm and a pressure transducer. The Pi‐Di values were obtained from digital angiographic images under continuous inflation of a canine femoral artery anastomosed with an expanded poly(tetrafluoroethylene) (ePTFE) vascular graft as a model vessel with a pressurized contrast medium. The Di at Pi using an NIH Image software specially programmed for the entropy filter method, which enables the detection of the edge of the vessel phantoms of the images, was determined. The Pi‐Di relationships showed a “J‐shape” curve for the artery, a steeper line with a very low pressure‐dependent distensibility for the ePTFE graft, and an intermediate curve for the anastomosis protion. The two indices for the vessel compliance, the stiffness parameter (β value) and the diameter compliance (Cd), both of which were calculated from the Pi‐Di relationships, were 10.6 and 6.8%/mmHg × 10‐2 for the artery, 164 and 0.51%/mmHg × 10‐2 for the ePTFE, and 14.4 and 5.5%/mmHg × 10‐2 for the anastomosis portion, respectively. This method can measure compliance at any portions of the sampling vessel in a single experiment on a real‐time basis with very high accuracy, compared with conventional methods, and even in cases of intimal thickening and/or connective tissues‐adhered vessels, and may serve to provide information on compliant design criteria of artificial and tissue‐engineered graft. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 191–195, 2002
Bone formation in transforming growth factor β‐1‐coated porous poly(propylene fumarate) scaffolds
Authors: Vehof Johan W. M. , Fisher John P. , Dean David , van der Waerden Jan‐Paul C. M. , Spauwen Paul H. M. , Mikos Antonios G. , Jansen John A.
Published: August 2002

This study determined the bone growth into pretreated poly(propylene fumarate) (PPF) scaffolds implanted into a subcritical size, rabbit cranial defect. PPF scaffolds were constructed by using a photocrosslinking‐porogen leaching technique. These scaffolds were then either prewetted (PPF‐Pw), treated with RF glow‐discharge (PPF‐Gd), coated with fibronectin (PPF‐Fn), or coated with rhTGF‐β1 (PPF‐TGF‐β1). One of each scaffold type was then placed into the cranium of nine rabbits. The rabbits were sacrificed after 8 weeks, and the scaffolds were retrieved for histological analysis. The most bone formation was present in the PPF‐TGF‐β1 implants; the newly formed bone had a trabecular appearance together with bone marrow‐like tissue. Little or no bone formation was observed in implants without rhTGF‐β1. These histological findings were confirmed by image analysis. Bone surface area, bone area percentage, pore fill percentage, and pore area percentage were significantly higher in the rhTGF‐β1‐coated implants than in the noncoated implants. No statistical difference was seen between the PPF‐Fn, PPF‐Pw, or PPF‐Gd scaffolds for these parameters. Quadruple fluorochrome labeling showed that in PPF‐TGF‐β1 implants bone formation mainly started in the interior of a pore and proceeded toward the scaffold. We conclude that (a) PPF‐TGF‐β1 scaffolds can indeed adequately induce bone formation in porous PPF, and (b) PPF scaffolds prepared by the photocrosslinking‐porogen leaching technique are good candidates for the creation of bone graft substitutes. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 241–251, 2002; DOI 10.1002/jbm.10073
Effect of experimental parameters on the in vitro release kinetics of transforming growth factor β1 from coral particles
Authors: Demers Caroline N. , Tabrizian Maryam , Petit Alain , Hamdy Reggie C. , Yahia L'Hocine
Published: August 2002

Coral bone graft substitutes have been supplemented in the past with growth factors to further enhance bone regeneration in defects. Little is known, however, on the dynamics of protein release from coral. Coral particles were studied for their ability to release transforming growth factor beta 1 (TGF‐β1) in vitro, under different adsorption conditions. Adsorption of TGF‐β1 (0.05 μg/mL) on coral particles (<80 μm or 300–450 μm) after 24 h of incubation was high, regardless of conditions. TGF‐β1 release kinetics in an artificial bone fluid followed a specific profile: an initial 1‐h protein burst, followed by a decreasing release during the next 24 h at which time the release increased again to reach a constant rate until the end of the 2‐week study. The protein release rate appeared mainly to depend upon the diffusion of TGF‐β1. TGF‐β1 release from coral particles was enhanced in the presence of bovine serum albumin (BSA) compared to the release in the presence of gelatin, and was dependent on the pH of adsorption. The highest total TGF‐β1 release was obtained when adsorption occurred with BSA at pH 7.4 (82 ± 3%), while the lowest release was observed when adsorption was done in the presence of gelatin at pH 11 (38 ± 1%). TGF‐β1 release was also found to vary with particle size, higher release being obtained with the smaller particles. These results suggest that coral particles could be used as a delivery system for growth factors, and that the release rate may be modulated through modification of the adsorption conditions and coral particle size. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 403–410, 2002
Electrochemical impedance spectroscopy and X‐ray photoelectron spectroscopy analysis of titanium surfaces cultured with osteoblast‐like cells derived from human mandibular bone
Authors: Mustafa Kamal , Pan Jinshan , Wroblewski Joanna , Leygraf Christofer , Arvidson Kristina
Published: August 2002

Variations in the oxide films on titanium surfaces blasted with TiO2 particles of various sizes were analyzed after cultures with cells derived from human mandibular bone. Turned titanium surfaces and surfaces blasted with 63–90‐, 106–180‐, and 180–300‐μm TiO2 particles were cultured with osteoblast‐like cells. The surfaces were characterized before and after the cell culture with electrochemical impedance spectroscopy (EIS). The surface chemical composition of selected samples was analyzed with X‐ray photoelectron spectroscopy (XPS). EIS revealed that with respect to the turned surfaces, the effective surface area was about 5, 6, and 4 times larger on the surfaces blasted with 63–90‐, 106–180‐, and 180–300‐μm particles, respectively. After 28 days of the cell culture, the corrosion resistance on all sample types was unaffected. The impedance characteristics suggest a considerable effect of ion incorporation and precipitation during culturing. XPS revealed that before the cell culture, a typical surface layer consisted of TiO2. After the culture, the surface oxide film contained both phosphorus and calcium, along with large amounts of oxidized carbon (carbonate) and nitrogen. There were lower concentrations of carbon and nitrogen on the blasted surfaces. We concluded that the effective surface area was several times higher on blasted surfaces than on turned surfaces. Cells derived from human mandibular bone affected ion incorporation into the implant surface. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 655–664, 2002
Predicted solution structure of zymogen human coagulation FVII
Authors: Perera Lalith , Darden Thomas A. , Pedersen Lee G.
Published: August 2002

A model solution structure for the complete tissue factor‐free calcium ion‐bound human zymogen FVII (residues 1–406) (FVII) has been constructed to study possible conformational changes associated with the activation process and tissue factor (TF) binding. The initial structure for the present model was constructed using the X‐ray crystallographic structure of human coagulation FVIIa/TF complex bound with calcium ions (Banner et al., Nature 1996, 380, 41–46). This model was subsequently subjected to lengthy molecular dynamics simulations. The Amber force field in conjunction with the PME electrostatic summation method was employed. The estimated TF free solution structure was then compared with the currently available X‐ray crystal structures of FVIIa (with or without TF, variable inhibitor bound) to estimate the restructuring of FVII due to TF binding and activation. The solution structure of the zymogen FVII in the absence of TF is predicted to be an extended domain structure similar to that of the TF‐bound X‐ray crystal structure. An additional extension of the serine protease (SP) domain of the zymogen above a reference lipid surface by ∼7 Å was in agreement with experiment. Significant Gla‐EGF1 and EGF1‐EGF2 interdomain motions in the zymogen were observed. Carbohydrate dimers attached to Ser‐52 and Ser‐60 did not cause restructuring in this domain. Minimal restructuring of the SP domain is found upon inference of the zymogen from the activated form. The catalytic triad residues maintain the H‐bonded network while Lys‐341 occupies the S1 specific site in the zymogen. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 35–47, 2002
Ethical behaviors of psychologists: Changes since 1987
Authors: Tubbs Paula , Pomerantz Andrew M.
Published: August 2002

Licensed psychologists (n = 92) in Illinois were surveyed regarding the frequency with which they engage in 82 behaviors of varying ethical appropriateness. For about one‐third of the behaviors studied, results differed significantly from a similar national survey published in 1987, such that the current sample reported never engaging in the behavior more frequently than did the previous sample. These differences may be due to increased involvement of managed care in professional practice, the revised ethical code, or regional or sampling factors. Implications of these results, including the need to assess ethical norms frequently, are discussed. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 395–399, 2001.
Compulsive checking behaviors in generalized anxiety disorder
Authors: Schut Alexander J. , Castonguay Louis G. , Borkovec Thomas D.
Published: August 2002

Recent evidence suggests that a relationship exists between worry, the central feature of generalized anxiety disorder (GAD), and compulsive behaviors, particularly compulsive checking. In this article we report the results from two studies. The first study assessed the frequency of obsessions and compulsions in 107 principally diagnosed GAD clients. The second study examined levels of alexithymia in analogue samples of GAD checkers (n = 31), GAD noncheckers (n = 30), and non‐GAD nonchecking controls (n = 27) using the Toronto Alexithymia Scale‐20 (Bagby, Parker, & Taylor, 1994). The results from these studies suggest that compulsive behaviors in the form of compulsive checking is more common in GAD than previously expected and that such behaviors in GAD may act as an additional mechanism by which affective experiences are avoided. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 705–715, 2001.
Liquid–liquid extraction of Hg(II) from acidic chloride solutions using bis‐2‐ethylhexyl sulfoxide
Authors: Francis Tania , Ramamohan Tumkur , Reddy Mundlapudi Lakshmipathi
Published: August 2002

The liquid–liquid extraction of Hg(II) from acidic chloride solutions has been studied using bis‐2‐ethylhexyl sulfoxide (B2EHSO) as an extractant. For comparison, extraction studies have also been carried out using di‐n‐octyl sulfoxide (DOSO) and diphenyl sulfoxide (DPhSO). The extraction data have been analysed by both graphical and theoretical methods taking into account aqueous phase speciation and all plausible complexes extracted into the organic phase. These results demonstrate that Hg(II) is extracted into xylene as HgCl2.3R2SO (where R2SO represents the sulfoxide). The equilibrium constant of the extracted complex has been deduced by non‐linear regression analysis. The developed liquid–liquid extraction procedure has been applied for the recovery of mercury from the brine‐sludge of a Chlor‐Alkali plant.

© 2001 Society of Chemical Industry
Epidemiology of particulate air pollution: exploiting observable exposure variability
Authors: III C. Arden Pope
Published: August 2002

Epidemiological studies of PM pollution and health have attempted to exploit observable sources of exposure variability to evaluate potential health consequences. These studies have become increasingly ingenious and rigorous in their ability to use natural exposure variability. Although a large majority of studies have evaluated only changes in short‐term exposures, long‐term, chronic exposure may be more important in terms of overall public health. This paper outlines the various dimensions of natural PM exposure variability that have been exploited in the epidemiology of PM literature, discuss how this exposure variablilty has or has not been utilized in recent epidemiology studies of PM exposure and human health, outline the inferences being drawn from the studies, and present the major limitations of these studies.Copyright © 1999 John Wiley & Sons, Ltd.
Localization of sarcoglycan, neuronal nitric oxide synthase, β‐dystroglycan, and dystrophin molecules in normal skeletal myofiber: Triple immunogold labeling electron microscopy
Authors: Wakayama Yoshihiro , Inoue Masahiko , Kojima Hiroko , Murahashi Makoto , Shibuya Seiji , Oniki Hiroaki
Published: August 2002

In order to investigate the mode of existence of the sarcoglycan complex, neuronal nitric oxide synthase (nNOS), β‐dystroglycan, and dystrophin in the normal skeletal myofiber, we examined the ultrastructural localization and mutual spatial relationship of nNOS, β‐dystroglycan, dystrophin, and the individual components of the sarcoglycan complex by using triple immunogold labeling electron microscopy. Each molecule of α‐, β‐, γ‐ and δ‐sarcoglycans is located intracellularly or extracellularly near the muscle plasma membrane mostly in accordance with the sarcoglycan antigenic sites against which the antibodies were generated. The association of different two and/or three sarcoglycan molecules out of α‐, β‐, γ‐ and δ‐sarcoglycan molecules was frequently observed. Each molecule of nNOS, β‐dystroglycan, and dystrophin was ultrastructurally noted along the cell surface of normal skeletal myofibers. Moreover, the close relation of a sarcoglycan molecule with β‐dystroglycan and dystrophin, and the association of nNOS with dystrophin were also confirmed ultrastructurally. Thus, this study demonstrated that the constituting molecules of the sarcoglycan complex, nNOS, β‐dystroglycan, and dystrophin existed in the form of a cluster at the normal muscle plasma membrane. The association of nNOS with dystrophin and its associated glycoproteins may form a macromolecular signaling complex at the muscle plasma membrane. Microsc. Res. Tech. 55:154–163, 2001. © 2001 Wiley‐Liss, Inc.
Relative length of longest paths and cycles in 3‐connected graphs
Authors: Li Rao , Saito Akira , Schelp R.H.
Published: August 2002

For a graph G, let p(G) denote the order of a longest path in G and c(G) the order of a longest cycle in G, respectively. We show that if G is a 3‐connected graph of order n such that $\textstyle{\sum^{4}_{i=1}\,{\rm deg}_{G}\,x_{i} \ge {3\over2}\,n + 1}$ for every independent set {x1, x2, x3, x4}, then G satisfies c(G) ≥ p(G) − 1. Using this result, we give several lower bounds to the circumference of a 3‐connected graph. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 137–156, 2001
Consolidating the lessons of 50 years of ‘development’
Authors: Shepherd Andrew
Published: August 2002

The World Development Report 2000/01 builds a complex picture of poverty, and a comprehensive approach to its reduction, which challenges the still dominant neo‐liberal paradigm. The significance of inequality in determining the outcomes of economic growth, of vulnerability and the need for an agenda of social security or social protection represent advances in the discourse of international agencies. The uniform and simplistic solutions of the past are dismissed with recognition of the fragility of markets and the problems of privatization. The diversity of poverty is met by emphasis on country strategies, which need to address the issues faced by the losers from the process of economic growth. Diversity has been identified — it now needs analysis. The comprehensive approach advocated should help to stabilize development thinking, to move away from the pendulum swings of policy fashion. The constraints to poverty reduction are under‐emphasised — resources to provide safety nets; the problems of preventing or resolving conflict, and the potential political resistance from elites unconvinced that poverty is their problem. Nevertheless, the report provides a basis for building a new international coalition against poverty, with the Bank as one among several agencies, a situation in which it will need to clarify its role. Copyright © 2001 John Wiley & Sons, Ltd.
SMART‐PET: Multimodality white matter imaging and display without loss of quantitative information
Authors: Juengling Freimut D. , Kassubek Jan , Högerle Stefan , Nitzsche Egbert U. , Moser Ernst
Published: August 2002

Purpose

To improve analysis of cerebral white matter (WM) in fluoro‐deoxy‐glucose positron emission tomography (PET) images.

Materials and Methods

A multimodality analysis technique (segmented MRI and registered Talairach‐transformed PET [SMART‐PET]) was used for quantitative assessment of WM metabolism. Data processing included Talairach transformation of three‐dimensional magnetic resonance imaging (MRI) and subsequent automated segmentation and coregistration to normalized PET images. Color model transformations were used for combined display: the hue saturation value color model was regarded as a three‐dimensional data matrix, integrating quantitative voxel data of both modalities. The technique was applied in normal subjects and in patients suffering from different WM diseases. Regional analysis was performed to classify metabolic impairment on a five‐point scale.

Results

Using SMART‐PET, a considerable gain in image contrast for WM was achieved in all cases. In the normal subjects, WM metabolism was shown to be homogeneously unimpaired. Sum scores of regional analysis revealed metabolic WM changes in all patients. Extent of WM hypometabolism exceeded the extent of the lesions as delineated by MRI signal changes.

Conclusion

The potential of the method for further elucidation of the role of WM diseases in brain dysfunction in patients is discussed. J. Magn. Reson. Imaging 2002;15:456‐461. © 2002 Wiley‐Liss, Inc.
Texture detection of simulated microcalcification susceptibility effects in magnetic resonance imaging of breasts
Authors: James David , Clymer Bradley D. , Schmalbrock Petra
Published: August 2002

The presence, size, structure and clustering characteristics of microcalcifications can indicate breast cancer. The magnetic susceptibility of microcalcifications differs from soft biological tissues, leading to directional blurring effects that can be detected by statistical image processing methods. A study of the ability of statistical texture analysis to detect simulated localized blurring in magnetic resonance imaging (MRI) of dense breast is presented. This method can detect localized blurring with sensitivity of 88.89% to 94.44%, specificity of 99.72% to 100%, positive predictive value of 73.91% to 100% and negative predictive value of 99.91% to 99.95%. J. Magn. Reson. Imaging 2001;13:876–881. © 2001 Wiley‐Liss, Inc.
Stable isotope dilution negative ion chemical ionization gas chromatography–mass spectrometry for the quantitative analysis of paroxetine in human plasma
Authors: Leis Hans Jörg , Windischhofer Werner , Raspotnig Günther , Fauler Günter
Published: August 2002

A sensitive and specific method for the quantitative determination of paroxetine in human plasma is presented. After solvent extraction from plasma with hexane/ethyl acetate (1 : 1) at alkaline pH and derivatization to the pentafluorobenzyl carbamate derivative, paroxetine was measured by gas chromatography–negative ion chemical ionization mass spectrometry. The carboxylate anion at m/z 372 was obtained at high relative abundance. [2H6]‐labeled paroxetine was used as an internal standard and its rapid and facile preparation from the unlabeled compound is described. Calibration graphs were linear within a range of 0.094–12.000 ng ml−1 using 1 ml of plasma and 0.469–60 ng ml−1 using 200 µl of plasma. Intra‐day precision was 1.47% (0.375 ng ml−1), 3.16% (3 ng ml−1) and 1.37% (9 ng ml−1) for the low‐level method, and 3.37% (1.875 ng ml−1), 2.72% (15 ng ml−1) and 2.22% (45 ng ml−1) for the high‐level method. Inter‐day precision was 1.65% (0.375 ng ml−1), 2.13% (3 ng ml−1) and 1.66% (9 ng ml−1) for the low‐level method, and 1.10% (1.875 ng ml−1), 1.56% (15 ng ml−1) and 1.90% (45 ng ml−1) for the high‐level method. At the limit of quantification (0.094 ng ml−1), intra‐day precision was 4.30% (low‐level method) and 2.56% (high‐level method), and inter‐day precision was 3.23% (low‐level method) and 3.00% (high‐level method). The method is rugged, rapid and robust and has been applied to the batch analysis of paroxetine during pharmacokinetic profiling of the drug. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of liquid chromatography mobile phase buffer contents on the ionization and fragmentation of analytes in liquid chromatographic/ionspray tandem mass spectrometric determination
Authors: Zhao Jamie J. , Yang Amy Y. , Rogers J. Douglas
Published: August 2002

The effects of liquid chromatography mobile phase buffer contents on the ionization and fragmentation of drug molecules in liquid chromatographic/ionspray tandem mass spectrometric (LC/MS/MS) determination were evaluated for simvastatin (SV) and its hydroxy acid (SVA). The objective was to improve further the sensitivity for SV by overcoming the unfavorable condition caused by the formation of multiple major adduct ions and multiple major fragment ions when using ammonium as LC mobile phase buffer. Mobile phases (70:30 acetonitrile–buffer, 2 mM, pH 4.5) with buffers made from ammonium, hydrazine or alkyl (methyl, ethyl, dimethyl or trimethyl)‐substituted ammonium acetate were evaluated. Q1 scan and product ion scan spectra were obtained for SV in each of the mobile phases under optimized conditions. The results showed that, with the alkylammonium buffers, the alkylammonium‐adducted SV was observed as the only major molecular ion, while the formation of other adduct ions ([M + H]+, [M + Na]+ and [M + K]+) was successfully suppressed. On the other hand, product ion spectra with a single major fragment ion were not observed for any of the alkylammonium‐adducted SVs. The affinity of the alkylammoniums to SV and the basicity of the alkylamines are believed to be factors influencing the formation and abundance of molecular and fragment ions, respectively. Methylammonium acetate provided the most favorable condition among all the buffers evaluated and improved the sensitivity several‐fold for SV in LC/MS/MS quantitation compared with that obtained using ammonium acetate buffer. Better precision for SV in both Q1 and SRM scans was observed when using methylammonium buffer compared with those using ammonium buffer. The mobile phase buffer contents did not seem to affect the ionization, fragmentation and chromatography of SVA. The results of this evaluation can be applied to similar situations with other organic molecules in ionspray LC/MS/MS determination. Copyright © 2002 John Wiley & Sons, Ltd.
Turn‐on transient dynamics of a semiconductor laser with optical feedback
Authors: Torre M. S. , Masoller C.
Published: August 2002

We study the effect of lateral carrier diffusion on the transient turn‐on of a semiconductor laser with optical feedback. The numerical simulations are based on the Lang–Kobayashi model, and on an extension of the model that includes lateral profiles for the carrier density and the optical field. For moderately strong feedback, intensity pulses characterize the dynamics of the turn‐on, with a repetition rate at the external cavity round‐trip time. We find that carrier diffusion has an important effect when the laser is biased close to the solitary threshold. For low carrier diffusion the intensity drops to a nearly zero value in between the pulses; for fast carrier diffusion, the spatial holes in the carrier profile burned by the intensity pulses are quickly replenished, and the intensity does not decay to a zero value in between the pulses. The results of our analysis show that the effect of diffusion is qualitatively well modelled by a non‐linear gain saturation coefficient different from zero in the space‐independent Lang–Kobayashi model. Copyright © 2001 John Wiley & Sons, Ltd.
Downregulation of a unique photoreceptor protein correlates with improper outer segment assembly
Authors: Wohabrebbi Amira , Umstot Edward S. , Iannaccone Alessandro , Desiderio Dominic M. , Jablonski Monica M.
Published: August 2002

A unique photoreceptor protein has been characterized. This protein, termed XAP‐1 antigen, is expressed by photoreceptors exclusively under conditions in which the outer segment membranes are properly assembled. When the retinal pigment epithelium is adherent to the underlying neural retina, the XAP‐1 antigen is localized to the plasma membrane that surrounds the inner and outer segments in the areas juxtaposed to the subretinal space. A similar labeling pattern is detected in retinal pigment epithelium‐deprived retinas in which assembly of nascent outer segments is supported by lactose. In retinas that undergo degeneration subsequent to the removal of the retinal pigment epithelium, the expression of this protein is completely downregulated. Immunohistochemical analyses and subcellular fractionation along with Western blot analysis, indicate that the XAP‐1 antigen is a membrane‐associated soluble protein. Mass spectrometric analysis indicates that the XAP‐1 antigen shares homology via 12 tryptic peptide masses with the gamma‐crystallin (lens structural protein) subclasses, although it does not immunolocalize to the same ocular structures as reported for the gamma‐crystallins. We propose that XAP‐1 antigen is a unique protein that is expressed extensively by healthy photoreceptor cells; the expression of the XAP‐1 antigen exclusively by photoreceptors with organized outer segments suggests that this protein may play a critical role in outer segment assembly. © 2002 Wiley‐Liss, Inc.
Vibrational analysis of Ni(II)‐ and Cu(II)‐octamethylchlorin by polarized resonance Raman and Fourier transform infrared spectroscopy
Authors: Lipski Robert J. , Unger Esko , Dreybrodt Wolfgang , Militello Valeria , Leone Maurizio , Schweitzer‐Stenner Reinhard
Published: August 2002

We measured the polarized resonance Raman spectra of Cu(II)‐2,2,7,8,12,13,17,18‐octamethylchlorin in CS2 at various excitation wavenumbers in a spectral region covering the Qy, Qx and Bx optical absorption bands. Additionally, we measured the FTIR‐Raman spectrum of the highly overcrowded spectral region between 1300 and 1450 cm−1. The spectral decomposition was carried out by a self‐consistent global fit to all spectra obtained. The thus identified Raman and IR lines were assigned by comparison with the resonance Raman spectra of Cu(II)‐octaethylporphyrin, by utilizing their depolarization ratio dispersions and by a normal mode analysis. The latter was based on a modified transferable molecular mechanics force field of Ni(II)‐octaethylporphyrin [E. Unger, M. Beck, R.J. Lipski, W. Dreybrodt, C.J. Medforth, K.M. Smith and R. Schweitzer‐Stenner, J. Phys. Chem. B 103, 10229 (1999)]. A comparison of normal mode patterns obtained for Cu(II)‐octamethylchlorin and Cu(II)‐octaethylporphyrin revealed that some modes are significantly distorted by the reduction of the pyrrole ring, in accordance with results which Boldt et al. reported earlier for Ni(II)‐octaethylchlorin [N.J. Boldt, F.J. Donohoe, R.R. Birge and D.F. Bocian, J. Am. Chem. Soc. 109, 2284 (1987)]. In contrast to conclusions drawn from this study, however, the results of our vibrational analysis and several further lines of evidence suggest that the normal modes of corresponding chlorines and porphyrins are still comparable, because they display contributions from the same local coordinates. Thus, the classical normal mode classification developed for metalloporphyrins is also applicable to metallochlorins. Finally, we performed a preliminary analysis of the absorption spectrum and the resonance excitation profiles and depolarization ratio dispersions of some Raman lines. The results show that the electronic properties of Cu(II)‐octamethylchlorin can still be described in terms of Gouterman's four orbital model [M. Gouterman, J. Chem. Phys. 30, 1139 (1959)]. In regions of the Q bands, Raman scattering of A1 modes is determined by interferences between Franck– Condon coupling and interstate Herzberg– Teller coupling between Qx(Qy) and Bx(By) states. The B2 modes are resonance enhanced by Herzberg– Teller coupling between Qx and Qy and between Qx(Qy) and By(Bx). Franck– Condon coupling of A1 modes with large contributions from CαCm stretching vibrations is comparatively strong for Qx. This is interpreted as reflecting the expansion of the chlorin macrocycle by an electronic transition into this excited state. Copyright © 2001 John Wiley & Sons, Ltd.
Comparison of resonance Raman spectra of flavin‐3,4‐dihydroxybenzoate charge‐transfer complexes in three flavoenzymes
Authors: Zheng Yuangang , Massey Vincent , Schaller Andreas , Palfey Bruce A. , Carey Paul R.
Published: August 2002

Various flavoenzymes can form charge‐transfer (CT) complexes with their substrates or analogs. The CT bands are red‐shifted from the flavin absorption bands. In the present study, under the resonance Raman condition when 647.1 nm excitation was used, resonance Raman spectra were obtained for three CT complexes formed by 3,4‐dihydroxybenzoic acid (protocatechuic acid, PCA) with the flavoenzymes old yellow enzyme I (OYE I), 12‐oxophytodienoate 10,11‐reductase (LeOPR I) and dihydroorotate dehydrogenase A (DHOD A). Many flavin ring modes were intensity‐enhanced under these conditions, although to varying degrees. However, the Raman intensity enhancements of the PCA modes were highly selective. Using phenolate binding to OYE I as a model system, and deuterium substitution in PCA, the enhanced modes were identified as benzene in‐plane ring modes containing contributions from C–H bending. The intensity enhancement for these modes is up to several thousand‐fold. The mechanism for the selective intensity enhancement is not understood. Although the CT absorption bands for PCA binding to OYE I, DHOD A and LeOPR I are very similar, the positions of the Raman modes of bound PCA and their response to deuterium substitution are distinct. This demonstrates that the Raman data can detect differences in the chemistry of the CT binding sites that are not apparent in the absorption spectral data. Copyright © 2001 John Wiley & Sons, Ltd.
Enhancing effect of chemically reduced gold on surface Raman scattering for organic sulfides chemisorbed on iron
Authors: Lu Yun , Chen Jin , Li Fengting , Xue Gi
Published: August 2002

Chemically reduced gold particles on an organic sulfide‐covered plate can effectively enhance surface Raman scattering signals. This method was used to investigate the adsorption states of 4‐aminophenyl disulfide and benzyl disulfide attached to the iron surface by Fourier transform surface‐enhanced Raman scattering. The results indicate that these sulfide molecules can be chemisorbed perpendicularly and form a self‐assembled film dotted with ferric hydroxide on the iron surface. Copyright © 2001 John Wiley & Sons, Ltd.
Investigations of micro‐stress and phase transition in sol–gel‐derived multideposited coatings of barium titanate using Raman spectroscopy
Authors: Gupta S.
Published: August 2002

Thin films of barium titanate (BaTiO3; BT) of various thicknesses (20, 60, 120, 160 and 200 nm) were deposited by a modified sol–gel route on M‐plane sapphire [Al2O3 : (1010)] substrates. Raman spectroscopy (RS) and x‐ray diffraction (XRD) were used to evaluate the stress and structural changes with respect to film thickness and establish a correlation. Raman bands and x‐ray peak intensities of 20 nm thick films were too weak to reveal any structural information. Structurally, all other films showed a polycrystalline nature and the average grain size increased with increasing thickness. From the changes in the lattice parameters and one of the Raman modes [B1 + E (TO)], an inverse relation between the compressive stress and film thickness was found at room temperature. Excellent agreement was found for stress values from both measurements. The ferroelectric to paraelectric phase transition (TC) was estimated from the temperature dependence of one of the lattice phonon (∼310 cm−1) wavenumber position (ω, cm−1) and linewidth (Γ, cm−1). This is one of the phonons belonging to the tetragonal phase. For thin films, these ‘order parameters’ did not show apparent anomaly and were qualitatively evaluated from the loss of intensity of this mode. The values of TC in thin films differ from those of the bulk counterpart. Almost an exponential decrease in the stress was observed with increasing thickness for the films due to the structural changes or lattice parameter relaxation. This behavior of TC is discussed using the conventional Landau–Devonshire theoretical formulation. Copyright © 2002 John Wiley & Sons, Ltd.
Taking risk in joint ventures: whose throw of the dice?
Authors: Sulej Julian C. , Stewart Victoria , Keogh William
Published: August 2002

The development of key partnerships between innovative small and medium‐sized enterprises (SMEs) and larger organizations is a primary strategic consideration. The level of risk involved can often mean that smaller firms are placed in highly vulnerable positions when attempting to develop a product, process or service.

Risk may be related to a wide range of influences including asymmetric resource allocation, the perception and framing of problems and the building of trust and commitment. The smaller organization may also have concerns that a larger partner would absorb their intellectual property.

Key considerations in determining perceived risk appear to be related to the shadow of the future, i.e. the balance of probabilities concerning investment and relative return combined with future expectations regarding any situation and its potential outcomes. The experience and individual agendas of managers and their influence on risk perception within such alliances are examined.

Future research using longitudinal studies to examine risk perception and evaluation in relation to strategic decision making is required.
Expression of cyclooxygenase‐2 in primary and remnant gastric carcinoma: Comparing it with p53 accumulation, Helicobacter pylori infection, and vascular endothelial growth factor expression
Authors: Kawabe Atsushi , Shimada Yutaka , Uchida Shigeki , Maeda Masato , Yamasaki Seiji , Kato Masayuki , Hashimoto Yosuke , Ohshio Gakuji , Matsumoto Masao , Imamura Masayuki
Published: August 2002

Background and Objectives

Cyclooxygenase‐2 (COX‐2) expression may contribute to the synthesis of prostanoids, which have been related to carcinogenesis and tumor progression. It is well known that the gastric remnant is at greater risk of the development of gastric cancer than is the whole stomach; incidence rates for gastric cardia adenocarcinoma are rising in the United States and Europe. Our objective was to determine the involvement of COX‐2 in primary and remnant gastric cancer tissues as well as in adjacent noncancerous mucosa.

Methods

We investigated the expression of COX‐2 in 91 human gastric cancer tissue and adjacent noncancerous mucosa samples (40 remnant gastric cancer, 37 gastric cardia cancer, and 14 gastric corpus and antrum cancer), using immunohistochemistry. In addition, p53 expression, Helicobacter pylori infection, and vascular endothelial growth factor in the tissues were evaluated by immunohistochemical staining and compared with COX‐2 expression.

Results

There were no significant differences in clinicopathological data in the gastric cancer tissues. There was a significant relation between the expression of COX‐2 and p53 in gastric cancer tissues (P = 0.0048). However, vascular endothelial growth factor expression and Helicobacter pylori infection showed no correlation with the expression of COX‐2. In the case of adjacent noncancerous mucosa, the positive rate of COX‐2 expression was significantly higher in the remnant gastric cancers (75.0%) than in the primary gastric cancers (25.5%) (P < 0.0001).

Conclusions

This information may help in the analysis of the carcinogenesis of gastric cancer; there is also a possibility that the COX‐2 selective inhibitor to the remnant gastric cancer has a chemopreventive effect. J. Surg. Oncol. 2002;80:79–88. © 2002 Wiley‐Liss, Inc.
Kinetics of HCCl + NOx reactions
Authors: Baren Randall E. , Erickson Mark A. , Hershberger John F.
Published: August 2002

The kinetics of reactions of HCCl with NO and NO2 were investigated over the temperature ranges 298–572 k and 298–476 k, respectively, using laser‐induced fluorescence spectroscopy to measure total rate constants and time‐resolved infrared diode laser absorption spectroscopy to probe reaction products. Both reactions are fast, with k(HCCl + NO) = (2.75 ± 0.2) × 10−11 cm3 molecule−1 s−1 and k(HCCl + NO2) = (1.10 ± 0.2) × 10−10 cm3 molecule−1 s−1 at 296 K. Both rate constants displayed only a slight temperature dependence. Detection of products in the HCCl + NO reaction at 296 K indicates that HCNO + Cl is the major product with a branching ratio of ϕ = 0.68 ± 0.06, and NCO + HCl is a minor channel with ϕ = 0.24 ± 0.04. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 12–17, 2002
Protection against human papillomavirus type 16‐E7 oncogene‐induced tumorigenesis by in vivo expression of dominant‐negative c‐jun†
Authors: Young Matthew R. , Farrell Linda , Lambert Paul , Awasthi Parirokh , Colburn Nancy H.
Published: August 2002

Expression of the human papillomavirus (HPV) type 16 E6 and E7 gene products is a risk factor for human cervical carcinogenesis as well as skin and oral carcinogenesis. Expression of the HPV‐16 E7 gene in mouse skin induces hyperplasia and enhances tumor promotion. Expression of dominant‐negative c‐jun (TAM67) in the mouse skin protects mice from 7,12‐dimethylbenz[a]anthracene (DMBA)/12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)–induced papillomagenesis without blocking mitogen‐induced hyperproliferation. To determine the role of activator protein‐1 (AP‐1) in HPV‐induced cancer, we crossed HPV‐16 E7 mice with TAM67 mice and analyzed the effects of DMBA/TPA on tumor promotion. We showed that expression of TAM67 protected mice from HPV‐16 E7–enhanced tumorigenesis, suggesting AP‐1 as a target for prevention of HPV‐induced cancer. Published 2002 Wiley‐Liss, Inc.
Profiling of differentially expressed genes induced by high linear energy transfer radiation in breast epithelial cells
Authors: Roy Debasish , Calaf Gloria , Hei Tom K.
Published: August 2002

Methods to define patterns of gene expression have applications in a wide range of biological systems. Several molecular biological techniques are used to study expression patterns during the neoplastic progression of breast epithelial cells. In the present study, differential expression of human oncogenes/tumor suppressor genes in human breast epithelial cell lines irradiated with low doses of high linear energy transfer radiation and treated with estrogen was assessed with cDNA expression arrays. Transformed and tumorigenic cell lines were compared with the control cell line to identify differentially expressed genes during tumorigenic progression. Autoradiographic analysis showed that of the 190 genes analyzed, 49 genes showed a high level of altered expression, and 12 genes had minor differences in expression levels. Among these 49 genes, 17 genes were altered at all stages of transformation, 21 were altered only at the early stage, and the remaining 11 were at the late stage of transformation to the tumorigenic stage of progression. Among the 11 late stage–associated genes, seven genes were altered exclusively in the tumorigenic cell lines and in Tumor‐T. Of the 17 all‐stage genes, six were randomly selected, and we confirmed their altered expression by gene‐specific semiquantitative reverse transcription polymerase chain reaction, followed by Northern blot analysis. The results showed that the mRNA expression patterns of all these genes were consistent with the expression pattern seen on the array. Among these six genes, five genes, including c‐myc, puf, MNDA, c‐yes, and Fra‐1 showed upregulation, and the other gene, RBA/p48, showed downregulation in the transformed and tumorigenic cell lines compared with the control MCF‐10F cell line. Investigation of these genes should help establish the molecular mechanisms of progression that are altered by radiation and estrogen treatment. A number of candidates reported here should be useful as biomarkers involved in breast carcinogenesis. © 2001 Wiley‐Liss, Inc.
Fast optical flip‐flop by use of Mach–Zehnder interferometers
Authors: Hill Martin T. , De Waardt H. , Khoe G. D. , Dorren H. J. S.
Published: August 2002

Optical flip‐flops formed from two coupled Mach–Zehnder interferometers are presented. The interferometers employ semiconductor optical amplifiers in their arms. The flip‐flops are demonstrated via simulations and experiments. Low switching energy and very high speed are possible in spite of the relatively slow semiconductor optical amplifier carrier recovery time. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 411–415, 2001.
S‐Parameter broadband measurements of microstrip lines and extraction of the substrate intrinsic properties
Authors: Hinojosa J. , Faucon L. , Queffelec P. , Huret F.
Published: August 2002

A measurement technique for the broadband determination of the complex permittivity and permeability of isotropic film‐shaped materials is presented. εr and μr are computed from S‐parameter measurements of microstrip lines propagating in the dominant mode and used as cells. The material under test is the microstrip‐line substrate, which is the original feature of this method in comparison with existing techniques. This leads to a simple and reproducible measurement process. Measurements for several materials in the 0.05–40 GHz frequency range show good agreement between measured and predicted data. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 65–69, 2001.
Oxazine‐ and oxazole‐fused derivatives of the alkaloid boldine and their complete structural and spectral assignments by HMQC and HMBC experiments
Authors: Sobarzo‐Sánchez Eduardo , Cassels Bruce K. , Saitz‐Barría Claudio , Jullian Carolina
Published: August 2002

The novel heterocycles 1,11‐dimethoxy‐2‐hydroxy‐6‐methyloxazolo[4,5‐k]‐5,6,6a,7‐tetrahydro‐4H‐dibenzo [de,g]quinoline, 1,12‐dimethoxy‐2‐hydroxy‐6‐methyl‐9‐phenyl‐10H‐oxazin[5,6‐k]‐5,6,6a,7‐tetrahydro‐4H‐ dibenzo[de,g]quinolin‐10‐one and 1,11‐dimethoxy‐2‐hydroxy‐6‐methyl‐9‐phenyloxazolo[4,5‐k]‐5,6,6a,7‐tetrahydro‐4H‐dibenzo[de,g]quinoline were prepared starting from the alkaloid boldine. The structures were confirmed and the 1H and 13C NMR spectra were completely assigned using a combination of one‐ and two‐dimensional NMR techniques. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of the absolute stereochemistry of vitamin E derived oxa‐spiro compounds by NMR spectroscopy
Authors: Schröder Harald , Netscher Thomas
Published: August 2002

This contribution describes the structure elucidation of dimeric and trimeric oxidation products derived from natural (2R,4′R,8′R)‐α‐ and (2R,4′R,8′R)‐γ‐tocopherol, the most important lipid‐soluble vitamin E compounds and antioxidants in biological systems. Complete 1H and 13C NMR signal assignments have been obtained by combinations of one‐ and two‐dimensional NMR techniques. These structural investigations include full determination of stereochemistry and a study of dynamic processes. Copyright © 2001 John Wiley & Sons, Ltd.
Galactose metabolism in normal human lymphoblasts studied by 1H, 13C and 31P NMR spectroscopy of extracts
Authors: Wehrli, Suzanne L. , Reynolds, Robert , Chen, Jie , Yager Claire , Segal Stanton
Published: August 2002

The development of tools to follow and quantitate the fate of galactose in mammalian cells is crucial to the study and understanding of the inherited disorders of galactose metabolism. In this study we incubated normal human lymphoblasts with 1‐ or 2‐13C galactose for 2.5 or 5 h and prepared TCA extracts of the cells. The various galactose metabolites were identified and quantified using a combination of proton, carbon and phosphorus NMR spectra. Galactose‐1‐phosphate (gal‐1P), uridine diphosphogalactose, uridine diphosphoglucose and galactitol were present in the extracts. Average levels for gal‐1P were around 10 nmol/mg protein and for uridine diphosphoglucose, uridine diphosphogalactose and galactitol in the range of 0.5–2 nmol/mg protein. Galactonate was never found in any conditions. Percentage labeling could be estimated for gal‐1P and for the ribose carbons of AMP. The labeling agrees with a conversion of galactose to glucose through the Leloir pathway. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations used:

Asp

aspartate

CPD

composite pulse decoupling

gal‐1P

galactose‐1‐phosphate

GALT

galactose 1‐phosphate uridylyl transferase

GB

gaussian factor

Glu

glutamate

LB

line broadening

NOE

nuclear Overhauser effect

PPP

pentose phosphate pathway

TCA

trichloroacetic acid

TSP

trimethylsilylpropionic acid

UDPgal

uridine diphosphogalactose

UDPglu

uridine diphosphoglucose.
Edge‐cutsets in the directed hypercube
Authors: Mariz Paul L. , Shahriari Shahriar
Published: August 2002

Let n ≥ 2 and 0 ≤ k ≤ n − 2 be integers. We show that given any collection of k skipless chains in 2[n], the Boolean lattice of order n, there exists n − k edge‐disjoint maximal chains that are edge‐disjoint from the original collection. We also characterize all collections of n − 1 pairwise edge‐disjoint skipless chains in 2[n] with the property that there is no maximal chain that is edge‐disjoint from the collection. Since the Hasse diagram of the Boolean lattice of order n is the n‐dimensional hypercube, the results are applicable to the directed hypercube network. © 2002 Wiley Periodicals, Inc.
A meshless method for Kirchhoff plate bending problems
Authors: Leitão Vitor M. A.
Published: August 2002

In this work a meshless method for the analysis of bending of thin homogeneous plates is presented. This meshless method is based on the use of radial basis functions to build an approximation of the general solution of the partial differential equations governing the Kirchhoff plate bending problem. In order to obtain a symmetric and non‐singular linear equation system the Hermite collocation method is used. To assess the formulation a series of plates with different boundary conditions are analysed. Comparisons are made with other results available in the literature. Copyright © 2001 John Wiley & Sons, Ltd.