bluuebunny/crossref_metadata_2025 huggingface dataset:
Kubelka‐munk analysis of absorptance in the presence of scattering, including surface‐reflection correction to transmittance
Authors: Shah H. S. , Billmeyer Fred W.
Published: June 2007

The absorption of optical radiation by an (incidentally) fluorescent absorbing material was studied in the presence of substantial amounts of scattering. If surface‐reflection corrections are neglected, the apparent absorptance of the system is “enhanced” in the presence of scattering. However, in this case attempts to use the Kubelka‐Munk turbid‐medium theory to compute the results do not lead to an accurate and adequate explanation. If surface‐reflection corrections are applied, all observed phenomena can be explained, but a negative enhancement is predicted. A new Saunderson‐type correction equation for surface reflection of the diffuse internal transmittance is derived and applied. Fluorescence does not contribute to the phenomena studied since measurements were limited to wavelengths outside the fluorescent emission spectral region.
Metric coefficients for CIE color‐difference formulas
Authors: Macadam David L.
Published: June 2007

Metric coefficients, for which formulas are given for the CIELUV and CIELAB color‐difference equations, are compared graphically and with published values for one observer, PGN. The corresponding chromaticity differences for any deviation from any point in the CIE x,y chromaticity diagram are easily determined from the metric coefficients.
Comparison of methods for assessing observer metamerism
Authors: Nayatani Yoshinobu , Hashimoto Kenjiro , Takahama Kotaro , Sobagaki Hiroaki
Published: June 2007

Studies on observer metamerism reported so far are classified into two series. One is studies based on the color‐matching functions of Stiles's 20 observers. The other is experimental studies by using the Davidson and Hemmendinger (D‐H) Color Rule and color‐normal actual observers. The large discrepancy of the degree of observer metamerism between the above two series of studies was analyzed by using the color‐matching functions of Stiles's 20 observers and the D–H Color Rule. The results confirmed that the discrepancy in the observer‐metamerism indices was caused by different computational procedures used for deriving the indices.
Science and art, objective and subjective
Authors: Birren Faber
Published: June 2007

A leading writer in the field of color raises objections to the intrusion of factual science into the subjective realm of the artist. The plea is for greater tolerance.
Successive heterochromatic brightness matches for a LED display
Authors: Ronchi Lucia R.
Published: June 2007

An experiment is described in which red and green pointlike sources are flashed in succession on nearby locations on the retina of the eye. While keeping the intensity of the green light fixed, the red's intensity is varied until a heterochromatic brightness match is attained. As the retinal image is more and more defocussed by the use of a blurring lens, less and less red light is needed to match the green reference light, both in the central retina and at moderate eccentricities, while the far periphery shows an insensitivity to blur. The result is tentatively explained by extending to peripheral vision some speculations concerning the brightness–luminance discrepancy in central vision. As a practical implication, it is noted that the photometric assessment of small sources, holding for the plane in which the eye is at focus, may exhibit deviations even as large as 0.5 log units when passing to defocussed locations.
The first color education in Japan
Authors: Ogata Kohji
Published: June 2007

The Meiji era (1868–1912) stands out as a period of radical modernization in Japan. For this reason, the Meiji Government paid special attention to the introduction of Western culture and civilization into modern Japanese society. Irozu (Color Chart) as the first attempt at color education in Japan resulted from one of these attempts at modernization. Iro‐zu was a direct copy of Willson's Charts for object lessons which were prevalent in the United States at that time. Willson's Charts themselves had been substantiated by color science in the Western world, especially the works of the English chemist Field and the French chemist Chevreul. On the contrary, Iro‐zu education almost abandoned the scientific meanings which Willson's Charts carried. According to the reformation of the educational system in 1879, Iro‐zu education was gradually reduced. Though Iro‐zu education lasted only five or six years, it has great importance as it marks the beginning of color education in Japan.
Growth and photoluminescence properties of CdS solid solution semiconductor
Authors: Chen Fuyi , Jie Wanqi
Published: June 2007

Photoluminescence (PL) emitted from Cd1‐xZnxS and CdS1‐ySey solid solution semiconductor was significantly stronger than PL from the pure CdS and CdSe semiconductor. The samples were prepared using an improved Se‐S‐Na2S flux route. Photoluminescence in Cd1‐xZnxS crystal was brightly yellow at the room temperature under VU radiation. The phase and composition of the solid solution was measured by the XRD and was confirmed by UV‐NIS spectrum as x of 0.3 and y of 0.2. The enhanced photoluminescence was presumably due to the introduction of extra defect (vacancies) by solid solution action and consequently the increasing of luminescence center concentration. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis, characterization and X‐ray crystal structure of guanidinuim (pyridine‐2,6‐dicarboxylato)(pyridine‐2,6‐monocarboxylato) zincate(II) mono pyridine‐2,6‐dicarboxylic acid tetrahydrate
Authors: Aghabozorg H. , Sadr‐Khanlou E.
Published: June 2007

A new complex of Zinc(II) and guanidinium pyridine–2,6–dicarboxylate proton transfer compound, (GnH)2 (pydc), was synthesized and characterized using IR, 1H NMR and 13C NMR spectroscopy and single crystal X–ray diffraction. The chemical formula and space group of the resulting complex is (GnH)[Zn(pydc)(pydcH)] · (pydcH2) · 4H2O, P 1 where the final R value is 0.0310 for 13287 reflections collected. The [Zn(pydc)(pydcH)]– anions and the (GnH)+ counter‐cations form a three‐dimensional solid‐state structure by a variety of noncovalent interactions such as ion pairing, hydrogen bonding and π–π stacking which are going to be discussed. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vivo imaging in experimental preclinical tumor research–A review
Authors: Wessels J. T. , Busse A. C. , Mahrt J. , Dullin C. , Grabbe E. , Mueller G. A.
Published: June 2007

The multiparametric molecular cell and tissue analysis in vitro and in vivo is characterized by rapid progress in the field of image generation technologies, sensor biotechnology, and computational modeling. Fascinating new potentials in unraveling the detailed functions of single cells, organs, and whole organisms are presently emerging and permit the close monitoring i.e. tumor development or basic cell development processes with an unprecedented multiplicity of promising investigative possibilities. To answer basic questions of in vivo tumor development and progression fluorescence based imaging techniques provide new insights into molecular pathways and targets. Genetic reporter systems (eGFP, DsRED) are available and high sensitive detection systems are on hand. These techniques could be used for in vitro assays and quantified e.g. by microscopy and CCD based readouts. The introduction of novel fluorescent dyes emitting in the near infrared range (NIR) combined with the development of sensitive detector systems and monochromatic powerful NIR‐lasers for the first time permits the quantification and imaging of fluorescence and/or bioluminescence in deeper tissues. Laser based techniques particularly in the NIR‐range (like two‐photon microscopy) offer superb signal to noise ratios, and thus the potential to detect molecular targets in vivo. In combination with flat panel volumetric computed tomography (fpVCT), questions dealing e.g. with tumor size, tumor growth, and angiogenesis/vascularization could be answered noninvasively using the same animal. The resolution of down to 150 μm/each direction can be achieved using fpVCT. It is demonstrated by many groups that submillimeter resolutions can be achieved in small animal imaging at high sensitivity and molecular specificity. Since the resolution in preclinical small animal imaging is down to ∼10 μm by the use of microCT and to subcellular resolutions using (∼1 μm) microscope based systems, the advances of different techniques can now be combined to “multimodal” preclinical imaging and the possibilities for in vivo intravital cytometry now become within one's reach. © 2007 International Society for Analytical Cytology
Effect of pollution control on corporate financial performance in a transition economy
Authors: Earnhart Dietrich , Lizal Lubomir
Published: June 2007

This study analyzes the effect of pollution control on corporate financial performance in a transition economy. In particular, it assesses whether better pollution control, as measured by lower air pollutant emissions, improves or undermines financial success, as captured by accounting‐based measures of financial performance, e.g. profitability. For this assessment, this study analyzes the effect of air pollution control using a panel of Czech firms for the years 1996–1998. The analytical results indicate that better pollution control neither improves nor undermines financial success. These results provide no support for the hypothesis that pollution prevention, generated by improved production processes, led to lower costs, and thus, greater profitability. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Integration and communication as central issues in Dutch negotiated agreements on industrial energy efficiency
Authors: Bressers Hans , de Bruijn Theo , Dinica Valentina
Published: June 2007

This paper analyses specific aspects of the implementation of the second multi‐annual agreement for energy efficiency concluded in the Netherlands with various industrial sectors for the period 2002–2010. The agreement is a follow‐up on a previous negotiated agreement that was generally seen as successful. This successor aims at stretching the limits of feasible and reasonably cost‐effective improvements in energy efficiency. In order to achieve this, so‐called ‘expansion themes’ were included that typically urge communication and tuning between companies as they exceed the level of individual companies: sustainable products, sustainable industrial estates, sustainable transport and logistics and sustainable energy. While the potential benefits are very promising, the first years of implementation mostly taught lessons on the difficulties that have to be overcome in order to achieve these. This paper will discuss the emerging obstacles and positive experiences with the implementation of the expansion theme measures. Special attention will be given to the role of the ‘consultation groups’, which supervise the implementation of the sector agreements and consist of representatives of the relevant industry sector organization, government and an advisory agency. This follow‐up consultation after the agreement is concluded to play an important role in stimulating integration issues such as the coherence of the energy efficiency measures in the sector, the tuning with other environmental and energy policies of government and the mutual trust between the partners.

The paper is based on the official evaluation of this negotiated agreement by the authors, which was commissioned by the Dutch ministry for economic affairs. The results are not only informative on this particular negotiated agreement, but also provide lessons on the integration and communication aspects of this policy strategy in general. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Liquid Crystal Imidazolium Salts: Towards Materials for Catalysis and Molecular Electronics
Authors: Suisse Jean‐Moïse , Douce Laurent , Bellemin‐Laponnaz Stéphane , Maisse‐François Aline , Welter Richard , Miyake Yasuo , Shimizu Yo
Published: June 2007

1,3‐Bis(4‐alkyloxyphenyl)‐3H‐imidazol‐1‐ium trifluoromethanesulfonates, alkyl = CH3(CH2)n–1, n = 8, 10, 12, 14 and 16, can be derived from the analogous 4‐alkyloxyphenylamines. These imidazolium salts exhibit a lamellar liquid‐crystal mesophase between 99 °C and 191 °C. The smectic‐A phase was fully characterised by polarising optical microscopy, differential scanning calorimetry and X‐ray diffraction. We report also the synthesis, lamellar crystal structure and catalytic activity of the PdII complex of the (deprotonated) carbene form of one of these salts. In addition, we measured the charged carrier mobilities in the mesophase.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Distinct regulation of MHC molecule expression on astrocytes and microglia during viral encephalomyelitis
Authors: Hamo Ludwig , Stohlman Stephen A. , Otto‐Duessel Maya , Bergmann Cornelia C.
Published: June 2007

The potential interplay of glial cells with T cells during viral induced inflammation was assessed by comparing major histocompatibility complex molecule upregulation and retention on astrocytes and microglia. Transgenic mice expressing green fluorescent protein under control of the astrocyte‐specific glial fibrillary acidic protein promoter were infected with a neurotropic coronavirus to facilitate phenotypic characterization of astrocytes and microglia using flow cytometry. Astrocytes in the adult central nervous system up‐regulated class I surface expression, albeit delayed compared with microglia. Class II was barely detectable on astrocytes, in contrast to potent up‐regulation on microglia. Maximal MHC expression in both glial cell types correlated with IFN‐γ levels and lymphocyte accumulation. Despite a decline of IFN‐γ concomitant to virus clearance, MHC molecule expression on glia was sustained. These data demonstrate distinct regulation of both class I and class II expression by microglia and astrocytes in vivo following viral induced inflammation. Furthermore, prolonged MHC expression subsequent to viral clearance implies a potential for ongoing presentation. © 2007 Wiley‐Liss, Inc.
Verbal memory performance improved via an acute administration of D‐amphetamine
Authors: Zeeuws Inge , Soetens Eric
Published: June 2007

Background

An improved long‐term retention of verbal memory was observed after an acute D‐amphetamine administration. It was proposed that D‐amphetamine modulates consolidation, but a possible drug effect on retrieval could not be rejected.

Objectives

We want to provide additional support for the consolidation hypothesis, and investigate whether an influence on intervening retrieval can be refuted.

Methods

Thirty‐six male paid volunteers participated in a double blind, counterbalanced, placebo‐controlled design in which the number of intermediate free recall tests was manipulated.

Results

A significant D‐amphetamine facilitation effect on recall performance emerged 1 h and 1 day after list learning. In line with the consolidation hypothesis, no effect was found on immediate tests. Importantly, the number of intermediate retrievals did not affect the magnitude of the drug effect, suggesting that the D‐amphetamine facilitation effect is independent of retrieval.

Conclusion

The D‐amphetamine facilitation effect on verbal memory does not involve a modulation of the initial encoding or short‐term memory (STM) processes. Moreover, the drug does not enhance long‐term retention by acting on intervening retrieval processes. The current findings are in line with the conjecture of an involvement of the consolidation process in the D‐amphetamine facilitation effect on verbal memory in healthy humans. Copyright © 2007 John Wiley & Sons, Ltd.
Conjunctive water management options: examples from economic assessment of system‐level water saving through Liuyuankou Irrigation System, China
Authors: Khan Shahbaz , Mushtaq Shahbaz , Luo Yufeng , Dawe David , Hafeez Mohsin , Rana Tariq
Published: June 2007

The paper provides results of a study aimed at saving a substantial amount of water by maintaining deeper groundwater levels to prevent fallow evaporation and by reducing the cost of groundwater abstraction for lowland farmers. An integrated LIS economic appraisal model was developed that linked simulated response of hydrological modelling of different conjunctive management options with economic analysis.

The simulation results of the LIS system dynamic model show that a combination of canal lining and pumping groundwater is the most cost‐effective way to reduce non‐beneficial evapotranspiration and increase water availability by saving up to 68 MCM of water. The simulation results of economic parameters indicated that canal lining and pumping also offer highest net economic benefits (¥21.98 million). Among other options, canal lining also indicates reasonably high net economic benefits (¥9.02 million). The model indicates a small increase in marginal value of water with canal lining (¥1.53 m−3) and pumping and canal lining (¥1.62 m−3). Among other options, the marginal capital cost of water saving for pumping and canal lining together was the lowest (¥0.096 m−3). However, the marginal capital cost of water saving for pumping and shifting canal water downstream was the most expensive (¥1.046 m−3). Copyright © 2007 John Wiley & Sons, Ltd.
Biocompatibility of novel polymer‐apatite nanocomposite fibers
Authors: Dimitrievska Sashka , Petit Alain , Ajji Abdellah , Bureau Martin N. , Yahia L'Hocine
Published: June 2007

On the basis of the bioactivity of hydroxyapatite (HA) and the excellent mechanical and biocompatible performance of polyethylene terephthalate (PET), composite microfibers made of nanograde HA with PET was designed and fabricated to mimic the structure of biological bone, which exhibits a composite of nanograde apatite crystals and natural polymer. The PET/HA nanocomposite was molded into fibers so that the bulk structures' mechanical properties can be custom tailored by changing the final 3D orientation of the fibbers. This study focused on the in vitro biocompatibility evaluation of the PET/HA composite fibers as potential bone fixation biomaterial for total hip replacement prosthesis surfaces. The MTT assay was performed with the extracts of the composite fibers in order to evaluate the short‐term effects of the degradation products. The cell morphology of L929 mouse fibroblast cell line was analyzed after direct contact with the fiber scaffolds for different time periods, and the cell viability was also analyzed by the Alamar Blue assay. The release of the inflammatory cytokine, tumor necrosis factor‐alpha (TNF‐α), from RAW 264.7 macrophages in the presence of fiber extracts and fibers was used as a measure of the inflammatory response. The ability of the fiber matrices to support L929 attachment, spreading, and growth in vitro, combined with the compatible degradation extracts and low inflammation potential of the fibers and extracts, suggests potential use of these fibers as load‐baring bone fixation biomaterial structures. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
A mesoporous bioactive glass/polycaprolactone composite scaffold and its bioactivity behavior
Authors: Li Xia , Shi Jianlin , Dong Xiaoping , Zhang Lingxia , Zeng Hongyu
Published: June 2007

Composite scaffolds of mesoporous bioactive glass (MBG)/polycaprolactone (PCL) and conventional bioactive glass (BG)/PCL were fabricated by a solvent casting‐particulate leaching method, and the structure and properties of the composite scaffolds were characterized. The measurements of the water contact angles suggest that the incorporation of either MBG or BG into PCL can improve the hydrophilicity of the composites, and the former is more effective than the later. The bioactivity of the composite scaffold is evaluated by soaking the scaffolds in a simulated body fluid (SBF) and the results show that the MBG/PCL composite scaffolds can induce a dense and continuous layer of apatite after soaking in SBF for 3 weeks, as compared with the scattered and discrete apatite particles on the BG/PCL composite scaffolds. Such improvements (improvements of the hydrophilicity and apatite forming ability) should be helpful for the extensive applications of PCL scaffold in tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Amorphous hydroxyapatite‐sintered polymeric scaffolds for bone tissue regeneration: Physical characterization studies
Authors: Cushnie Emily K. , Khan Yusuf M. , Laurencin Cato T.
Published: June 2007

Given the inherent shortcomings of autografts and allografts, donor‐site morbidity and risk of disease transmission, respectively, alternatives to traditional bone grafting options are warranted. To this end, poly(lactide‐co‐glycolide) (PLAGA) and in situ‐synthesized amorphous hydroxyapatite (HA) were used to construct three‐dimensional microsphere‐based composite scaffolds of varying HA content for bone regeneration. In the current study, the effect of adding amorphous HA to the PLAGA scaffolds on their physical characteristics and in vitro degradation mechanism was investigated. Porosimetry and uniaxial compression testing were used to analyze the internal structure and elastic modulus of the scaffolds, respectively. Additionally, gel permeation chromatography (GPC) was performed to assess the polymer molecular weight over the course of an 8‐week degradation study. HA content (17% or 27%) of the composite scaffolds was found to increase scaffold pore volume from 33.86% for pure polymer scaffolds, to 40.49% or 46.29%, depending on the amount of incorporated HA. This increased pore volume provided the composite scaffolds with a greater surface area and a corresponding decrease in elastic modulus. Scaffold degradation studies conducted over 8 weeks showed PLAGA to degrade in a first‐order mechanism, with the rate of polymer degradation for the 27% HA composite scaffold being significantly slower than that of the pure PLAGA scaffold (degradation constants of 0.0324 and 0.0232 week−1, respectively). These results suggest that the addition of amorphous HA to PLAGA microspheres resulted in porous, bioactive scaffolds that offer potential as alternative bone grafting materials for the field of regenerative medicine. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
An optimized β‐tricalcium phosphate and agarose scaffold fabrication technique
Authors: Román J. , Cabañas M.V. , Peña J. , Doadrio J.C. , Vallet‐Regí M.
Published: June 2007

Biodegradable scaffolds composed of β‐tricalcium phosphate, and a natural hydrogel, agarose, were prepared by a shaping method based on the thermal gelation of the polymeric component. This technique was modified to facilitate the inclusion, during the scaffold preparation stage, of therapeutic agents that could improve the graft performance. Vancomycin was included in materials containing different amounts of agarose and ceramic without affecting the scaffold consolidation process. These materials, easily injectable, behave like a reinforced hydrogel whose swelling behavior and drug release rate depend on their composition. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Recognitive biomimetic networks with moiety imprinting for intelligent drug delivery
Authors: Byrne Mark E. , Hilt J. Zachary , Peppas Nicholas A.
Published: June 2007

Molecular imprinting techniques have been developed for the preparation of biomimetic polymer networks that can recognize a general moiety, D‐glucose, and the novel evaluation of loading and release of a larger molecule with glucose as an integral part of its structure [i.e., fluorescently tagged glucose (2‐(N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl)amino)‐2‐deoxy‐glucose) or 2‐NBDG]. Poly(acrylamide‐co‐poly(ethylene glycol)dimethacrylate) networks with varying crosslinking monomer percentages (80, 67, and 30%) and crosslinker lengths (average number of ethylene glycol units of 1, 4, and 14) were prepared and characterized using a novel fluorescent microscopy technique, which allowed for microscale observation of the dynamic binding and release of 2‐NBDG within the polymer film. Experimental results indicate that tighter mesh‐sized networks had increased affinity and capacity towards the glucose functionalized molecule as well as increased diffusional transport times, indicating the strong potential to load significantly higher amounts of therapeutic within intelligent carriers as well as control and extend the rate of release via macromolecular structure. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Semiconductor stocks: Signaling a bear market?
Authors: Tokic Damir
Published: June 2007

The S & P 500 index has been in an up‐trend since March 2000. But during the same period, semiconductor stocks have had a flat performance. Since many analysts see semiconductor stocks as leading market indicators, is the recent broad market up‐trend just a cyclical bounce in a bear market? © 2007 Wiley Periodicals, Inc.
Coping with the new E‐discovery rules
Authors: Mooney J. Lowell , Wright Harry R.
Published: June 2007

Over the past few years, companies have gradually abandoned paper records. They've shifted to electronic communication and records. But now, IT staff and corporate counsel are grappling with a whole new set of rules governing electronic legal evidence. What electronic information must you preserve? And how can you control the spiraling costs involved—and avoid crippling damage awards for failure to comply? The authors have some answers, including special guidelines for the chief financial officer's role in all this. © 2007 Wiley Periodicals, Inc.
Outsourcing problem: The right‐to‐audit clause
Authors: Smith Gordon
Published: June 2007

Companies are outsourcing more IT functions these days. But many outsourcing contracts fail to include something that's very critical: a right‐to‐audit clause. Is your company leaving itself vulnerable here? And what should you do about it? © 2007 Wiley Periodicals, Inc.
Endless inefficient meetings? Try CMS
Authors: Burnett Royce D. , Friedman Mark , Lynch Antoinette L.
Published: June 2007

CEOs and top managers often find themselves in an endless series of meetings. And new responsibilities—along with an accelerated flood of information—have made the problem worse. But using a computer‐mediated system (CMS) to share and manage information can greatly improve your efficiency and effectiveness. The authors explain how to do it. © 2007 Wiley Periodicals, Inc.
Danger–corporate data breach!
Authors: Cannon David M. , Kessler Lara
Published: June 2007

It's time to sound the alarm. The number and consequences of corporate data breaches are growing by leaps and bounds. People often see data breaches as an information technology problem. But the fallout often affects the finance function. And while stolen consumer information gets the most publicity, sensitive employee and business partner data has also been stolen.

The authors reveal the technological, legal, and market forces causing the growth of data breaches. They also explore the impact of these breaches, as well as current legal moves to address the problem. © 2007 Wiley Periodicals, Inc.
Managing the risks of IT outsourcing
Authors: Bi Lily
Published: June 2007

There have been many debates about whether to outsource a company's IT services—and if so, how to do it. But now that the first generation of IT outsourcing is behind us, the author argues that we should embrace a strategic approach that aligns sourcing with business goals. © 2007 Wiley Periodicals, Inc.
Mathematical modeling of 13C label incorporation of the TCA cycle: The concept of composite precursor function
Authors: Uffmann Kai , Gruetter Rolf
Published: June 2007

A novel approach for the mathematical modeling of 13C label incorporation into amino acids via the TCA cycle that eliminates the explicit calculation of the labeling of the TCA cycle intermediates is described, resulting in one differential equation per measurable time course of labeled amino acid. The equations demonstrate that both glutamate C4 and C3 labeling depend in a predictible manner on both transmitochondrial exchange rate, VX, and TCA cycle rate, VTCA. For example, glutamate C4 labeling alone does not provide any information on either VX or VTCA but rather a composite “flux”. Interestingly, glutamate C3 simultaneously receives label not only from pyruvate C3 but also from glutamate C4, described by composite precursor functions that depend in a probabilistic way on the ratio of VX to VTCA: An initial rate of labeling of glutamate C3 (or C2) being close to zero is indicative of a high VX/VTCA. The derived analytical solution of these equations shows that, when the labeling of the precursor pool pyruvate reaches steady state quickly compared with the turnover rate of the measured amino acids, instantaneous labeling can be assumed for pyruvate. The derived analytical solution has acceptable errors compared with experimental uncertainty, thus obviating precise knowledge on the labeling kinetics of the precursor. In conclusion, a substantial reformulation of the modeling of label flow via the TCA cycle turnover into the amino acids is presented in the current study. This approach allows one to determine metabolic rates by fitting explicit mathematical functions to measured time courses. © 2007 Wiley‐Liss, Inc.
The neural pathway of galanin in the hypothalamic arcuate nucleus of rats: Activation of beta‐endorphinergic neurons projecting to periaqueductal gray matter
Authors: Sun Yan‐Gang , Gu Xing‐Long , Yu Long‐Chuan
Published: June 2007

We have previously shown that microinjection of galanin into the arcuate nucleus of hypothalamus (ARC) produced antinociceptive effects in rats (Sun et al., 2003a). In this study, the neural pathway of galanin from ARC to midbrain periaqueductal gray (PAG) in nociceptive modulation was investigated. The hindpaw withdrawal latencies (HWLs) with noxious thermal and mechanical stimulation were assessed by the hotplate and the Randall Selitto tests. Intra‐ARC administration of 0.1, 0.5, or 1 nmol of galanin induced significant increases in HWLs of rats. The galanin‐induced increases in HWLs were inhibited by injection of 10 μg of the opioid receptor antagonist naloxone or 1 nmol of the mu‐opioid receptor antagonist beta‐funaltrexamine (beta‐FNA) into PAG, suggesting that the antinociceptive effects induced by intra‐ARC injection of galanin occur via the neural pathway from ARC to PAG. Furthermore, our results demonstrate that the galaninergic fibers directly innervated the beta‐endorphinergic neurons in ARC by immunofluorescent methods. Taken together, our results suggest that galanin produces antinociceptive effects in the ARC of rats by activating the beta‐endorphinergic pathway from ARC to PAG. © 2007 Wiley‐Liss, Inc.
A novel compound, maltolyl p‐coumarate, attenuates cognitive deficits and shows neuroprotective effects in vitro and in vivo dementia models
Authors: Shin Ki Young , Lee Geon Ho , Park Cheol Hyoung , Kim Hee Jin , Park Soo‐Hyun , Kim Seonghan , Kim Hye‐Sun , Lee Kwan‐Sun , Won Beom Young , Lee Hyung Gun , Choi Jin‐Ho , Suh Yoo‐Hun
Published: June 2007

To develop a novel and effective drug that could enhance cognitive function and neuroprotection, we newly synthesized maltolyl p‐coumarate by the esterification of maltol and p‐coumaric acid. In the present study, we investigated whether maltolyl p‐coumarate could improve cognitive decline in scopolamine‐injected rats and in amyloid beta peptide1–42‐infused rats. Maltolyl p‐coumarate was found to attenuate cognitive deficits in both rat models using passive avoidance test and to reduce apoptotic cell death observed in the hippocampus of the amyloid beta peptide1–42‐infused rats. We also examined the neuroprotective effects of maltolyl p‐coumarate in vitro using SH‐SY5Y cells. Cells were pretreated with maltolyl p‐coumarate, before exposed to amyloid beta peptide1–42, glutamate or H2O2. We found that maltolyl p‐coumarate significantly decreased apoptotic cell death and reduced reactive oxygen species, cytochrome c release, and caspase 3 activation. Taking these in vitro and in vivo results together, our study suggests that maltolyl p‐coumarate is a potentially effective candidate against Alzheimer's disease that is characterized by wide spread neuronal death and progressive decline of cognitive function. © 2007 Wiley‐Liss, Inc.
Stimulation of H2O2 generation by calcium in brain mitochondria respiring on α‐glycerophosphate
Authors: Tretter Laszlo , Takacs Katalin , Kövér Kinga , Adam‐Vizi Vera
Published: June 2007

It has been reported recently (Tretter et al., 2007b) that in isolated guinea pig brain mitochondria supported by α‐glycerophosphate (α‐GP) reactive oxygen species (ROS) are produced through the reverse electron transport (RET) in the respiratory chain and by α‐glycerophosphate dehydrogenase (α‐GPDH). We studied the effect of calcium on the generation of H2O2 as measured by the Amplex Red fluorescent assay in this model. H2O2 production in α‐GP‐supported mitochondria was increased significantly in the presence of 100, 250, and 500 nM Ca2+, respectively. In addition, Ca2+ enhanced the membrane potential, the rate of oxygen consumption, and the NAD(P)H autofluorescence in these mitochondria. Direct measurement of α‐GPDH activity showed that Ca2+ stimulated the enzyme by decreasing the Km for α‐GP. In those mitochondria where RET was eliminated by the Complex I inhibitor rotenone (2 μM) or due to depolarization by ADP (1 mM), the rate of H2O2 formation was smaller and the stimulation of H2O2 generation by Ca2+ was prevented partly, but the stimulatory effect of Ca2+ was still significant. These data indicate that in α‐GP‐supported mitochondria activation of α‐GPDH by Ca2+ leads to an accelerated RET‐mediated ROS generation as well as to a stimulated ROS production by α‐GPDH. © 2007 Wiley‐Liss, Inc.
PEDF‐derived synthetic peptides exhibit antitumor activity in an orthotopic model of human osteosarcoma
Authors: Ek Eugene T. H. , Dass Crispin R. , Contreras Karla G. , Choong Peter F. M.
Published: June 2007

Pigment epithelium‐derived factor (PEDF) is one of the most potent inhibitors of angiogenesis, and has recently been demonstrated to have an important multifunctional role in tumor growth, invasion, and metastasis. However, relatively little is known of mechanisms through which PEDF exerts its antitumor activity. Therefore, with the aim of identifying potential functional epitopes specifically against osteosarcoma, we evaluated the bioactivity of four 25‐mer synthetic PEDF‐derived peptides (termed StVOrth‐1, ‐2 ‐3, and ‐4) against a human osteosarcoma cell line, SaOS‐2. We found that StVOrth‐2 (residues 78–102) predominantly inhibited tumor cell proliferation, while StVOrth‐3 (residues 90–114) markedly increased cellular adhesion to collagen type‐1, with StVOrth‐4 (residues 387–411) demonstrating most significant inhibition of Matrigel invasion. Furthermore, we show that StVOrth‐1 (residues 40–64), ‐2 and ‐3 induce osteoblastic differentiation, evidenced by increased mineralized nodule formation. Interestingly, although no peptide inhibited angiogenesis in the tube formation assay, StVOrth‐3 and ‐4 markedly suppressed VEGF expression. We further tested the activity of StVOrth‐2 and StVOrth‐3 in vivo, in an orthotopic model of osteosarcoma and found that both peptides significantly inhibited primary tumor growth and the development of pulmonary metastases. Together these results provide greater insight into the potential mechanisms through which PEDF exerts its antitumor function. Furthermore, this raises the possibility of developing short PEDF fragments as lead compounds for the treatment of osteosarcoma. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1671–1680, 2007
Development of the supraspinatus tendon‐to‐bone insertion: Localized expression of extracellular matrix and growth factor genes
Authors: Galatz Leesa , Rothermich Stefan , VanderPloeg Kristin , Petersen Bryan , Sandell Linda , Thomopoulos Stavros
Published: June 2007

The adult healing response of the rotator cuff tendon‐to‐bone insertion site differs from the ordered process of insertion site development. Healing is characterized by disorganized scar and a lack of fibrocartilage formation, in contrast to the well organized fibrocartilaginous transition which forms during the normal development of the tendon‐to‐bone insertion. The purpose of this study was to localize the expression of a number of extracellular matrix and growth factor genes during insertion site development in order to guide future strategies for augmenting adult rotator cuff healing. The rotator cuff was morphologically distinct at 13.5 dpc (days postconception). Neo‐tendon was evident as a condensation of cells adjacent to bone. The interface between tendon and bone did not form into a mature fibrocartilaginous insertion until 21‐days postnatally, based upon the appearance of four distinct zones with a mineralized humeral head. Fibroblasts of the supraspinatus tendon expressed type I collagen at all timepoints. Type II collagen was first expressed by chondrocytes in the fibrocartilage and mineralized fibrocartilage at 7 days and persisted in the mineralized fibrocartilage at 56 days. Type X collagen was first expressed by the chondrocytes in the mineralized fibrocartilage at 14 days and persisted in the mineralized fibrocartilage at 56 days. A shift from TGF‐β3 to TGF‐β1 expression occurred at 15.5 dpc. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1621–1628, 2007
Effects of Botox® and Neuronox® on muscle force generation in mice
Authors: Stone Austin V. , Ma Jianjun , Whitlock Patrick W. , Koman L. Andrew , Smith Thomas L. , Smith Beth P. , Callahan Michael F.
Published: June 2007

The current study determined the dose–response relationship for inhibition of muscle force of two commercially available botulinum neurotoxin type‐A (BoNTA) preparations (Botox® and Neuronox®) in a murine model and characterized the time course of recovery from the toxin‐induced muscle paralysis. The effect of freezing reconstituted toxin on toxin potency was also determined. The gastrocnemius muscles in male CD‐1 mice were injected with either saline or BoNTA (0.3–3.0 U/kg), and muscle force generation was examined following stimulation of the tibial nerve (single twitch and 15–200 Hz tetany). Botox and Neuronox produced nearly equivalent decrements in muscle force (30%–90%) at 4 days after toxin injection. At 28 days after injection (1 U/kg), muscle force had recovered from the effects of both toxin preparations. Maintaining reconstituted toxin at −80°C for up to 5 months did not result in significant loss of toxin activity. The results of this study suggest that Botox and Neuronox produce equivalent responses in a murine model, and, in contrast to other models, muscle recovery is rapid with doses of toxin that produce less than maximal decrements in muscle force. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1658–1664, 2007
‘It is better to beg forgiveness than to ask permission’: tourism development in an unregulated town
Authors: Ross Andrew J. , Riley Roger W. , Rumpca Tiffany L.
Published: June 2007

This study describes the state of a Costa Rican community as it is affected by tourism development. It suggests reasons for the current state of affairs and offers potential solutions to remedy this town's issues. By gathering data on location through the use of interviews with business owners, the issue of individual development versus community development is exposed. It provides a glimpse into the concept of group dynamics and collective action (or the lack of it), and offers some understanding about collective development in unregulated communities. Copyright © 2007 John Wiley & Sons, Ltd.
Complications Associated with Percutaneous Placement of Venous Return Cannula for Venovenous Bypass in Adult Orthotopic Liver Transplantation†
Authors: Sakai Tetsuro , Planinsic Raymond M. , Hilmi Ibetsam A. , Marsh Wallis J.
Published: June 2007

Percutaneous large bore cannula placement during orthotopic liver transplantation (OLT) for use in venovenous bypass (VVB) has been reported to be a rapid and simple technique. It is, however, a technique that carries its own risks. The aim of the study was to investigate the incidence of complications related to the placement of a percutaneous venous return cannula and subsequent VVB in OLT. A retrospective review of 360 consecutive adult OLT patients during a period of 18 months (January 1, 2003 to June 30, 2004) was performed. The percutaneous venous cannula (18 Fr) was placed by an attending transplant anesthesiologist. The cannulation was attempted in 326 patients (90.6%). No cannulation was attempted on the subclavian veins. Internal jugular venous cannula placement was attempted but aborted in 6 patients (1.8%) due to technical difficulties. In 320 patients who received an internal jugular venous cannula, 313 (97.8%) underwent OLT without complication. The remaining 7 patients (2.2%) had complications. The operation was delayed for 1 patient due to suspected hemomediastinum. The other 6 complications were related to VVB: air embolism (2 patients), low flow rate (2 patients), hypotension (1 patient), and atrial fibrillation (1 patient). Successful OLT was eventually carried out in all the 7 patients and no mortality associated with internal jugular venous cannula placement or VVB was noted. In conclusion, percutaneous placement of a large bore venous return cannula for VVB during adult OLT can be performed with acceptable risk using a flexible 18-Fr cannula via the right internal jugular vein (IJV) by experienced attending transplant anesthesiologists. Liver Transpl 13:961–965, 2007. © 2007 AASLD.
A Prospective Evaluation of Fibrosis Progression in Patients with Recurrent Hepatitis C Virus Following Liver Transplantation†
Authors: Yilmaz Nevin , Shiffman Mitchell L. , Stravitz Todd R. , Sterling Richard K. , Luketic Velimir A. , Sanyal Arun J. , Mills Scott A. , Contos Melissa J. , Coterell Adrian , Maluf Daniel , Posner Marc P. , Fisher Robert A.
Published: June 2007

Recurrence of hepatitis C virus (HCV) following liver transplantation (LT) is universal. A subset of these patients develop advanced fibrosis and cirrhosis and it is believed that this leads to increased posttransplantation mortality. The specific aims of this study were to determine the incidence of advanced fibrosis and those factors associated with this process, and to evaluate causes for mortality in patients with recurrent HCV. A total of 227 patients who underwent LT with chronic HCV were monitored prospectively. The mean age of this group at LT was 49.5 yr; 76% were male and 85% were Caucasian. Fibrosis progression was monitored by protocol liver biopsy, initially performed 6 months after LT and then at 6- to 24-month intervals. Advanced fibrosis, defined as the bridging fibrosis or cirrhosis, developed in 1%, 11%, 25%, and 41% of patients after 1, 3, 5, and 6-10 yr, respectively. Acute cellular rejection hepatic steatosis, a persistent elevation in serum alanine aminotransferase and donor-race were associated with the development of advanced fibrosis. In contrast, the development of advanced fibrosis was not affected by the use of interferon prior to undergoing LT, cytomegalovirus disease, or donor age. A total of 60 patients (26%) died over 15 yr of follow-up. Although graft failure accounted for 45% of deaths in patients with advanced fibrosis, this represented only 8% of all deaths in patients with recurrent HCV. Sepsis was the most common cause of death and this was observed with similar frequency in patients who developed advanced fibrosis (45%) and in those with less advanced fibrosis (47%). In conclusion, approximately 41% of patients with recurrent HCV developed advanced fibrosis 6-10 yr after LT. However, complications associated with sepsis, not recurrent cirrhosis, was the most common cause of death in patients with recurrent HCV and this was similar in patients with or without advanced fibrosis. Liver Transpl 13:975–983, 2007. © 2007 AASLD.
Hepatic Stellate Cell Activation in Liver Transplant Patients with Hepatitis C Recurrence and in Non-Transplanted Patients with Chronic Hepatitis C
Authors: Cisneros Laura , Londoño Maria-Carlota , Blasco Carmen , Bataller Ramón , Miquel Rosa , Bruguera Miquel , Ginès Pere , Rimola Antoni
Published: June 2007

The pathogenic mechanisms of accelerated graft fibrosis in hepatitis C recurrence after liver transplantation (LT) are not well established. The aim of the study was to assess whether a greater activation of hepatic stellate cells (HSC), the major collagen-producing cells in the liver, can occur in these patients as compared to non-LT patients with chronic hepatitis C. We determined the amount of activated HSC by computer-based morphometric analysis of α-smooth muscle actin (αSMA)-positive cells and the hepatic TGFβ1 expression by immunohistochemistry in 46 LT patients with hepatitis C recurrence, 35 non-LT patients with chronic hepatitis C, and 16 controls. Hepatic αSMA and TGFβ1 expression was higher in LT patients with hepatitis C recurrence than in controls and was correlated with fibrosis stage and progression rate. No significant difference in αSMA and TGFβ1 expression was observed between LT and non-LT patients with hepatitis C, with the exception of a higher transforming growth factor β-1 (TGFβ1) expression in non-LT patients in the early stages of fibrosis. LT patients receiving cyclosporine (CsA) or tacrolimus (FK) had a similar fibrosis progression rate and αSMA and TGFβ1 expression. In conclusion, the accelerated fibrosis observed in LT patients with hepatitis C recurrence does not seem to be related to a greater amount of activated HSC and TGFβ1 expression in the grafts of these patients as compared to non-LT patients with chronic hepatitis C. In LT patients, the amount of activated HSC and TGFβ1 expression correlated with fibrosis stage and progression, without any apparent influence of the type of calcineurin inhibitor administered. Liver Transpt 13:1017–1027, 2007. © 2007 AASLD.
Anemia in Liver Transplant Recipients Undergoing Antiviral Treatment for Recurrent Hepatitis C
Authors: Saab Sammy , Oh Mina K. , Ibrahim Ayman B. , Durazo Francisco , Han Steven , Yersiz Hasan , Farmer Douglas G. , Ghobrial Mark R. , Goldstein Leonard I. , Tong Myron J. , Busuttil Ronald W.
Published: June 2007

Adherence to antiviral therapy is essential to achieve sustained virological responses in patients treated for hepatitis C. An important limitation to use of appropriate doses of ribavirin is development of anemia. The aim of this study is to identify risk factors associated with anemia in liver transplant recipients undergoing treatment for recurrent hepatitis C virus (HCV). Retrospective analysis was performed on 115 adult liver transplantation (LT) recipients who received antiviral treatment. Anemia was defined as hemoglobin of <10 gm/dL or the use of erythropoietin replacement therapy. Variables found to be significant in univariate analysis were further studied in multivariate analysis. The mean (± standard deviation [SD]) age of our cohort was 52.1 (± 8.8) yr. Anemia developed in 44 patients (38.3%). Mean (± SD) onset of anemia was 8.9 (± 6.8) weeks after initiation of antiviral therapy. A total of 30 patients (26%) required erythropoietin replacement, at a mean (± SD) of 7.9 (± 6.0) weeks after start of antiviral treatment. A total of 27 patients (24%) required ribavirin dose reduction, at a mean (± SD) time to dose reduction of 8.1 (± 6.3) weeks. In univariate analysis, body mass index (BMI) (P < 0.01), mycophenolate mofetil use (P = 0.05), trimethoprim-sulfamethoxazole (P = 0.02), and age (P = 0.02) were statistically significant. In conclusion, in multivariate analysis, BMI (P < 0.01) and age (P = 0.02) were found to be independent predictors of anemia. Anemia is common in liver transplant recipients treated for recurrent HCV. Special vigilance is required for older patients and patients with a low BMI. Liver Transpt 13:1032–1038, 2007. © 2007 AASLD.