bluuebunny/crossref_metadata_2025 huggingface dataset:
Causal discrete‐time system approximation of non‐bandlimited continuous‐time systems by means of discrete prolate spheroidal wave functions
Authors: Tzschoppe Roman , Huber Johannes B.
Published: August 2008

In general, linear time‐invariant (LTI) continuous‐time (CT) systems can be implemented by means of LTI discrete‐time (DT) systems, at least for a certain frequency band. If a causal CT system is not bandlimited, the equivalent DT system may has be to non‐causal for perfectly implementing the CT system within a certain frequency band. This paper studies the question to which degree a causal DT system can approximate the CT system. By reducing the approximation frequency band, the approximation accuracy can be increased‐‐‐at the expense of a higher energy of the impulse response of the DT system. It turns out, that there exists a strict trade‐off between approximation accuracy, measured in the squared integral error, and energy of the impulse response of the DT system. The theoretically optimal trade‐off can be achieved by approximations based on a weighted linear combination of the discrete prolate spheroidal wave functions (DPSWFs). The results are not limited to the case of approximating a CT system by means of a causal DT system, but they generally hold for the approximation of an arbitrary spectrum by means of a spectrum of an indexlimited time sequence. Copyright © 2008 John Wiley & Sons, Ltd.
The ‘forbidden theory of mountain uplift’ of Charles Taylor Trechmann (1884–1964): a tectonic theory of the 1950s in context
Authors: Donovan Stephen K.
Published: August 2008

C.A. Matley (1866–1947) recognised a Precambrian or Palaeozoic Basal Complex under Jamaica and the Caribbean, analogous to the Mona Complex he had mapped in northwest Wales. However, the existence of a Basal Complex in Jamaica remains unproven and unlikely. The principal opponent to the Basal Complex hypothesis was the only other major expert on the geology of Jamaica at this time, the independently wealthy amateur C.T. Trechmann (1884–1964). Subsequent to his debate with Matley, Trechmann changed the subject of his Caribbean research from stratigraphy and mollusc systematics to tectonics, and the formulation of his Theory of Mountain Uplift in competition with Matley's Basal Complex. Trechmann's theory suggested that uplift of mountains was the product of lunar attraction, reinforced by pressure produced by deep columns of ocean water which also induced metamorphic changes at relatively shallow crustal depths. Unfortunately, Matley died after the appearance of the first of four privately published monographs on mountain uplift, depriving Trechmann of the target audience for his theory. The Theory of Mountain Uplift was widely ignored at a time when the status of the amateur in geology was waning and Trechmann lacked disciples to spread his ideas. His was the last parochial theory of Antillean tectonics and is remembered for its errors, as seen from a present where plate tectonics provide the framework for all geology, rather than its adherence to the fixist research programmes of the first half of the 20th Century. Trechmann's theory was not just wrong, but it was wrong at the wrong time. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of the German reference drug program on ex‐factory prices of prescription drugs: a panel data approach
Authors: Augurzky Boris , Göhlmann Silja , Greß Stefan , Wasem Jürgen
Published: August 2008

This paper examines effects of the German social health insurance system's reference drug program (RDP) for prescription drugs on ex‐factory prices. Moreover, we analyze whether manufacturers adapt prices of their products that are not subject to reference pricing as a consequence of changes in reference prices of their products that are subject to reference pricing. We use econometric panel data methods based on a large panel data set of nearly all German prescription drugs on a monthly basis between October 1994 and July 2005. They provide information on ex‐factory prices, reference prices, manufacturers, type of prescription drug, and market entries and exits. Our results show that there is no full price adjustment: A 1%‐change in reference prices leads to a 0.3%‐change in market prices. Price adjustment, however, is fast – it mostly happens in the first month. Furthermore, the first introduction of a reference price reduces market prices of the affected products by approximately 7%. Finally, we observe a significant time effect that is positive in the market without reference prices and negative in the market with reference prices. Copyright © 2008 John Wiley & Sons, Ltd.
Weight and wages: fat versus lean paychecks
Authors: Han Euna , Norton Edward C. , Stearns Sally C.
Published: August 2008

Past empirical work has shown a negative relationship between the body mass index (BMI) and wages in most cases. We improve on this work by allowing the marginal effect of non‐linear BMI groups to vary by gender, age, and type of interpersonal relationships required in each occupation. We use the National Longitudinal Survey of Youth 1979 (1982–1998). We find that the often‐reported negative relationship between the BMI and wages is larger in occupations requiring interpersonal skills with presumably more social interactions. Also, the wage penalty increases as the respondents get older beyond their mid‐twenties. We show that being overweight and obese penalizes the probability of employment across all race–gender subgroups except black women and men. Our results for the obesity–wage association can be explained by either consumers or employers having distaste for obese workers. Copyright © 2008 John Wiley & Sons, Ltd.
Avoiding therapeutic pitfalls: The rational use of specifically targeted agents against hepatitis C infection
Authors: McGovern Barbara H. , Abu Dayyeh Barham K. , Chung Raymond T.
Published: August 2008

The development of specifically targeted antiviral agents against hepatitis C is a major therapeutic advance that promises to markedly improve treatment response rates in patients with chronic infection. However, rapid emergence of drug resistance has already been described, the consequences of which are not yet understood. Although there are important differences between hepatitis C (HCV) and human immunodeficiency virus (HIV) infection, the judicious use of candidate agents against HCV should be guided by principles that have been established in the HIV therapeutic arena. In this review, we attempt to draw useful parallels between the development of antiretroviral therapy for HIV and preliminary data on antiviral agents for hepatitis C virus infection. Applying concepts learned in HIV therapeutics will hopefully lead to a prudent and cautious path in HCV treatment paradigms, particularly with respect to drug resistance. (Hepatology 2008;48:1700–1712.)
Serum and ascitic fluid bacterial DNA: A new independent prognostic factor in noninfected patients with cirrhosis
Authors: Zapater Pedro , Francés Rubén , González-Navajas José M. , de la Hoz Maria A. , Moreu Rocío , Pascual Sonia , Monfort David , Montoliu Silvia , Vila Carmen , Escudero Amparo , Torras Xavier , Cirera Isabel , Llanos Lucía , Guarner-Argente Carlos , Palazón José M. , Carnicer Fernando , Bellot Pablo , Guarner Carlos , Planas Ramón , Solá Ricard , Serra Miguel A. , Muñoz Carlos , Pérez-Mateo Miguel , Such José
Published: August 2008

We tested the hypothesis that the presence of bacterial DNA (bactDNA) in ascitic fluid and serum is associated with decreased survival in patients with cirrhosis. In a prospective, multicenter study, we analyzed the clinical evolution of 156 patients with cirrhosis and ascites (first or recurrence) with lower than 250 polymorphonuclear cells (PMN)/μL, negative ascites bacteriological culture, and absence of other bacterial infections being admitted for evaluation of large-volume paracentesis, according to the presence of bactDNA at admission. Survival, causes of death, and successive hospital admissions were determined during a 12-month follow-up period. BactDNA was detected in 48 patients. The most prevalent identified bactDNA corresponded to

Escherichia coli

(n = 32/48 patients, 66.6%). Patients were followed for 12 months after inclusion and in this period 34 patients died: 16 of 108 (15%) bactDNA negative versus 18 of 48 (38%) bactDNA positive (

P

= 0.003). The most frequent cause of death was acute-on-chronic liver failure in both groups (7/16 and 9/18 in patients without or with bactDNA, respectively), although more prevalent in the first month of follow-up in patients with presence of bactDNA (0 versus 4/7). When considering patients with model for end-stage liver disease (MELD) score less than 15, mortality was significantly higher in those with presence of bactDNA. Spontaneous bacterial peritonitis developed similarly in patients with or without bactDNA at admission.

Conclusion

: The presence of bactDNA in a patient with cirrhosis during an ascitic episode is an indicator of poor prognosis. This fact may be related to the development of acute-on-chronic liver failure at short term and does not predict the development of spontaneous bacterial peritonitis. (Hepatology 2008;48:1924-1931.)
Levothyroxin restores hypothyroidism‐induced impairment of hippocampus‐dependent learning and memory: Behavioral, electrophysiological, and molecular studies
Authors: Alzoubi Karem H. , Gerges Nashaat Z. , Aleisa Abdulaziz M. , Alkadhi Karim A.
Published: August 2008

Hypothyroidism induces cognitive impairment in experimental animals and patients. Clinical reports are conflicting about the ability of thyroid hormone replacement therapy to fully restore the hypothyroidism‐induced learning and memory impairment. In this study, we investigated the effects of L‐thyroxin (thyroxin) treatment on hippocampus‐dependent learning and memory in thyroidectomized adult rats. In the radial arm water maze (RAWM) task, thyroxin treated thyroidectomized animals made significantly fewer errors than the untreated hypothyroid animals in Trial 3 of the acquisition phase, short‐term memory and long‐term memory tests. In addition, the number of errors made by the thyroxin treated thyroidectomized animals was not different from that of the control group. Furthermore, the days‐to‐criterion (DTC) values for thyroxin treated thyroidectomized animals were not different from those of the control group but significantly lower than those of the untreated hypothyroid animals. In anesthetized rats, extracellular recording from hippocampal area CA1 of hypothyroid rats shows that thyroxin treatment restores impaired Late‐phase long‐term potentiation (L‐LTP). Immunoblot analysis of signaling molecules, including cyclic‐AMP response element binding protein (CREB), mitogen‐activated protein kinases (MAPKp44/42; ERK1/2), in area CA1 revealed that thyroxin treatment reversed hypothyroidism‐induced reduction of signaling molecules essential for learning and memory, and L‐LTP. This study shows that thyroxin treatment reverses hypothyroidism‐induced impairment of hippocampus‐dependent cognition, and L‐LTP, probably by restoring the levels of signaling molecule important for these processes. © 2008 Wiley‐Liss, Inc.
Pyridoxine 5′‐phosphate oxidase, not pyridoxal kinase, involves in long‐term potentiation induction in the rat dentate gyrus
Authors: Kwak Sung‐Eun , Kim Ji‐Eun , Kim Dae‐Won , Kwon Oh‐Shin , Choi Soo‐Young , Kang Tae‐Cheon
Published: August 2008

In this study, we investigated whether the expression of pyridoxal kinase (PLK) and pyridoxine‐5′‐phosphate oxidase (PNPO) are altered following long‐term potentiation (LTP) induction, and whether Tat‐PLK and Tat‐PNPO transductions affect LTP induction and paired‐pulse responses in the rat dentate gyrus (DG). PNPO immunoreactivity was markedly increased in dentate granule cells after the induction of LTP, but that of PLK was not. Tat‐PNPO (20 and 200 μg/kg), but not Tat‐PLK or vitamin B6 precursors, treatments, increased the efficiency of high frequency stimulus‐induced potentiation of populations spike amplitude when compared with saline‐, or Tat‐protein‐treated animals. These changes correlated with the alterations in PNPO activity and its immunoreactivity. In addition, Tat‐PNPO transduction increased paired‐pulse facilitation but had no effect on the fast and late paired‐pulse inhibitions. These findings suggest that PNPO may play a role in activity‐dependent regulation of PLP level in the brain, which is involved in LTP induction and paired‐pulse facilitation but not in enhancement of GABAergic inhibition. © 2008 Wiley‐Liss, Inc.
β1‐ and β2‐Adrenoceptors in basolateral nucleus of amygdala and their roles in consolidation of fear memory in rats
Authors: Qu Li‐Li , Guo Nan‐Nan , Li Bao‐Ming
Published: August 2008

It is known that β‐adrenoceptor (AR) in the basolateral nucleus of amygdala (BLA) plays an essential role in fear memory formation. However, the cellular and subcellular distributions of β1‐ and β2‐ARs in the BLA and their roles in fear memory formation are poorly understood. Here, we report that both β1‐ and β2‐ARs are predominantly expressed in BLA neurons but not in astrocytes. β1‐AR is distributed in the cell membrane and cytoplasm of neurons, whereas β2‐AR is localized not only in the cell membrane and cytoplasm but also in the nucleus. Intra‐BLA infusion of the β1‐AR antagonist metoprolol and atenolol or the β2‐AR antagonist ICI118551 and butoxamine produces a severe deficit in 24‐h auditory fear memory, leaving 1‐h memory intact. Western‐blot analysis reveals that the protein level of cytoplasmic β1‐AR significantly increases 2‐ and 4‐h postconditioning, whereas that of cytoplasmic or nuclear β2‐AR is unchanged. The present results indicate that β1‐ and β2‐ARs in the BLA have differential subcellular localizations and both are required for the consolidation of auditory fear memory. © 2008 Wiley‐Liss, Inc.
Hippocampus, aging, and segregating memories
Authors: Manrique Tatiana , Morón Ignacio , Ballesteros María Angeles , Guerrero Rosa María , Fenton André A. , Gallo Milagros
Published: August 2008

Rats use time‐of‐day cues to modulate learned taste aversion memories. If adult rats are accustomed to drinking saline in the evening and they receive a lithium chloride injection after drinking saline in the morning, they form a stronger aversion to saline than rats that were conditioned after drinking saline at the familiar time. The difference indicated that the rats formed segregated representations of saline taste and the time of day the saline was consumed. This was inferred because the modulation of learning by time of day was observed when the aversions were tested at the familiar evening drinking time. If the rats had formed a compound representation of saline taste and the time of day it was consumed, the opposite pattern of differences would be expected. We used this modulation of learning by time of day to assay whether aged rats have an impaired ability to form segregated representations of experience. We find that aged rats had similar saline aversions if they were conditioned at either the familiar or the unfamiliar time of day. Furthermore, dorsal hippocampal lesions affecting also the overlying parietal cortex in the aged rats caused greater saline aversions if the rats were conditioned after drinking saline at the familiar time of day. This indicated that aged rats are aware of the time of day but after the lesion, they act as if they do not segregate saline taste from the time of day it was consumed. The results suggest that the ability to form segregated representations of a complex experience is impaired in aging and abolished by hippocampal lesions. © 2008 Wiley‐Liss, Inc.
Accuracy and convergence of free energy differences calculated from nonequilibrium switching processes
Authors: Goette Maik , Grubmüller Helmut
Published: August 2008

The molecular‐dynamics‐based calculation of accurate free energy differences for biomolecular systems is a challenging task. Accordingly, convergence and accuracy of established equilibrium methods has been subject of many studies, often focusing at small test systems. In contrast, the potential of more recently proposed nonequilibrium methods, derived from the Jarzynski and Crooks equalities, has not yet fully been explored. Here, we compare the performance of these methods by calculating free energy differences for test systems at different levels of complexity and varying extent of the involved perturbations. We consider the interconversion of ethane into methanol, the switching of a tryptophane‐sidechain in a tripeptide, and the binding of two different ligands to the globular protein snurportin 1. On the basis of our results, we suggest and assess a new nonequilibrium free energy method, Crooks Gaussian Intersection (CGI), which combines the advantages of existing methods. CGI is highly parallelizable and, for the test systems considered here, is shown to outperform the other studied equilibrium and nonequilibrium methods. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
A molecular mechanics force field for lignin
Authors: Petridis Loukas , Smith Jeremy C.
Published: August 2008

A CHARMM molecular mechanics force field for lignin is derived. Parameterization is based on reproducing quantum mechanical data of model compounds. Partial atomic charges are derived using the RESP electrostatic potential fitting method supplemented by the examination of methoxybenzene:water interactions. Dihedral parameters are optimized by fitting to critical rotational potentials and bonded parameters are obtained by optimizing vibrational frequencies and normal modes. Finally, the force field is validated by performing a molecular dynamics simulation of a crystal of a lignin fragment molecule and comparing simulation‐derived structural features with experimental results. Together with the existing force field for polysaccharides, this lignin force field will enable full simulations of lignocellulose. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
CHOP T/C and C/T haplotypes contribute to early‐onset type 2 diabetes in Italians
Authors: Gragnoli Claudia
Published: August 2008

Type 2 diabetes (T2D) is characterized by impaired insulin secretion, insulin insensitivity and decreased beta‐cell mass. Multiple genes contribute to T2D. The chromosome 12q13.1 region is in linkage to T2D in different populations, including our Italian dataset. CHOP is a candidate gene for the linkage, as it is located in the chromosome 12q13.1 region, and may contribute to T2D by increasing beta‐cell apoptosis susceptibility and by impairing insulin sensitivity. Our goal was to identify any potential CHOP gene variants contributing to T2D in our Italian early‐onset T2D families, which show linkage to the CHOP region. We directly sequenced the CHOP gene in 28 Italian probands of the linked T2D families and in 115 control subjects. We performed genotype and haplotype association tests with T2D of the identified single nucleotide polymorphisms (SNPs). We performed model‐free and parametric association haplotype tests with T2D. We identified three SNPs [5′UTR‐c.279T > C, 5′UTR‐c.120A > G and + nt30C > T (F10F)] in CHOP. These SNPs are in complete linkage disequilibrium. The genotype association test showed an association trend with T2D of TT (F10F) and AG (‐c.120A > G). The haplotype association test provided significant results for the haplotypes T/C (frequency = 0.33) and C/T (frequency = 0.01) (at 5′UTR‐c.279T > C and + nt30C > T, respectively) under non‐parametric analysis (P‐value = 0.0000), recessive model (P‐value = 0.0000) and additive model (P‐value = 0.0014). Our data show that CHOP described haplotypes T/C and C/T, as an additive and as a homozygous variant, contribute significantly to T2D in our Italian early‐onset group. We conclude that the CHOP T/C and C/T haplotype contributes to our T2D linkage signal on chromosome 12q13.1. J. Cell. Physiol. 217: 291–295, 2008. © 2008 Wiley‐Liss, Inc.
Batch treatment of saline wastewater by Halanaerobium lacusrosei in an anaerobic packed bed reactor
Authors: Kapdan Ilgi Karapinar , Boylan Burcu
Published: August 2008

BACKGROUND: This study considers batch treatment of saline wastewater in an upflow anaerobic packed bed reactor by salt tolerant anaerobic organisms Halanaerobium lacusrosei.

RESULTS: The effects of initial chemical oxygen demand (COD) concentration (COD0 = 1880–9570 mg L−1), salt concentration ([NaCl] = 30–100 g L−1) and liquid upflow velocity (Vup = 1.0–8.5 m h−1) on COD removal from salt (NaCl)‐containing synthetic wastewater were investigated. The results indicated that initial COD concentration significantly affects the effluent COD concentration and removal efficiency. COD removal was around 87% at about COD0 = 1880 mg L−1, and efficiency decreased to 43% on increasing COD0 to 9570 mg L−1 at 20 g L−1 salt concentration. COD removal was in the range 50–60% for [NaCl] = 30–60 g L−1 at COD0 = 5200 ± .100 mg L−1. However, removal efficiency dropped to 10% when salt concentration was increased to 100 g L−1. Increasing liquid upflow velocity from Vup = 1.0 m h−1 to 8.5 m h−1 provided a substantial improvement in COD removal. COD concentration decreased from 4343 mg L−1 to 321 mg L−1 at Vup = 8.5 m h−1, resulting in over 92% COD removal at 30 g L−1 salt‐containing synthetic wastewater.

CONCLUSION: The experimental results showed that anaerobic treatment of saline wastewater is possible and could result in efficient COD removal by the utilization of halophilic anaerobic bacteria. Copyright © 2008 Society of Chemical Industry
Density functional theory calculations and vibrational spectra of 3,5 dichloro hydroxy benzaldehyde and 2,4 dichloro benzaldehyde
Authors: Krishnakumar V. , Mathammal R.
Published: August 2008

The solid‐phase Fourier transform infrared (FT‐IR) and FT‐Raman spectra of 3,5 dichloro hydroxy benzaldehyde (DHB) and 2,4 dichloro benzaldehyde (DB) have been recorded in the regions 4000–400 and 4000–0 cm−1, respectively. Theoretical information on the optimized geometry, harmonic vibrational wavenumbers as well as infrared and Raman intensities were obtained by means of density functional theory (DFT) using standard B3LYP/6–31G** level. This information was used in the assignment of the various fundamentals. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes. Copyright © 2008 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering of protoberberine alkaloids
Authors: Cañamares M. V. , Lombardi J. R. , Leona M.
Published: August 2008

Quaternary protoberberine alkaloids are a class of natural dyes characterized by bright colors ranging from yellow to orange. As they present a strong fluorescence emission, their analysis by Raman spectroscopy is limited to specific techniques such as Fourier transform (FT)‐Raman and spectral shift Raman techniques such as shifted subtracted Raman difference spectroscopy (SSRDS) and shifted excitation Raman difference spectroscopy (SERDS). In a previous article, we successfully used surface‐enhanced Raman scattering (SERS) in the analysis of the alkaloid dye berberine in an ancient textile. The examination of the Raman and SERS spectra of berberine in combination with density functional theory (DFT) calculations indicated a flat adsorption geometry of the molecule on the Ag surface. In this article we extend that work to the study of related protoberberine alkaloids, palmatine, jatrorrhizine, and coptisine. The same adsorption geometry as in berberine was deduced. We found that the four alkaloids, although minimally different in their chemical structures, could be differentiated by the position of marker bands. Those bands are the most enhanced ones in the SERS spectra, which appear in the 700–800 cm−1 region. Copyright © 2008 John Wiley & Sons, Ltd.
Ultrafast vibrational dynamics and solvation complexes of methyl acetate in methanol studied by sub‐picosecond infrared spectroscopy
Authors: Banno Motohiro , Ohta Kaoru , Tominaga Keisuke
Published: August 2008

The vibrational dynamics of the CO stretching mode of methyl acetate (MA) in methanol was studied by time‐resolved infrared (IR) pump‐probe spectroscopy. The vibrational energy relaxation (VER) process includes two components with time constants of 1.3 ± 0.1 and 4.0 ± 0.2 ps. These components result from the vibrational excitations of the hydrogen‐bonding complex of MA with one methanol and the MA monomer, respectively. The difference in the VER time is explained by the increase of the vibrational density of states (VDOS) by the intermolecular hydrogen bond. The time constants and the decay‐associated spectra are almost identical between the CH3OH and the CH3OD solutions. The vibrational modes localized in the intramolecular OH/OD bond of the solvent methanol have little effect on the vibrational dynamics of MA. Copyright © 2008 John Wiley & Sons, Ltd.
Raman spectroscopy and microscopy of individual cells and cellular components
Authors: Chan J. , Fore S. , Wachsmann‐Hogiu S. , Huser T.
Published: August 2008

Raman spectroscopy provides the unique opportunity to nondestructively analyze chemical concentrations in individual cells on the submicrometer length scale without the need for optical labels. This enables the rapid assessment of cellular biochemistry inside living cells, and it allows for their continued analysis. Here, we review recent developments in the analysis of single cells, subcellular compartments, and chemical imaging based on Raman spectroscopy. Spontaneous Raman spectroscopy provides for the full spectral assessment of cellular biochemistry, while coherent Raman techniques, such as coherent anti‐Stokes Raman scattering is primarily used as an imaging tool comparable to confocal fluorescence microscopy. These techniques are complemented by surface‐enhanced Raman spectroscopy, which provides higher sensitivity and local specificity, and also extends the techniques to chemical indicators, i.e. pH sensing. We review the strengths and weaknesses of each technique, demonstrate some of their applications and discuss their potential for future research in cell biology and biomedicine.
EB1 acts as an oncogene via activating β‐catenin/TCF pathway to promote cellular growth and inhibit apoptosis
Authors: Liu Mei , Yang Shangbin , Wang Yihua , Zhu Hongxia , Yan Shuang , Zhang Wei , Quan Lanping , Bai Jinfeng , Xu Ningzhi
Published: August 2008

Previously we showed that end‐binding protein 1 (EB1) may promote cellular growth by activating β‐catenin/T‐cell factor (TCF) pathway. To further investigate the role of EB1 in regulating cellular growth, we established an EB1‐inducible expression system in which the protein level of EB1 was significantly upregulated upon doxycycline induction. We found that EB1 promoted cellular growth and resulted in a significant increase in colony formation. In addition, EB1 could induce tumor formation in nude mice, activate β‐catenin‐dependent gene expression and upregulate the transcriptional activity of c‐myc. We also showed that EB1 in this manner inhibited apoptosis of 293‐T‐REx cells upon cisplatin and upregulated expression of Bcl‐2, whereas ΔN TCF4, an inhibitor of β‐catenin/TCF pathway, could completely or partially abolish the effects of EB1 on the promotion of cell growth and the inhibition of apoptosis activity. Moreover, knockdown of c‐myc by RNAi could abrogate upregulation of EB1‐dependent induction of Bcl‐2 expression. Overall, EB1 acts as a potential oncogene via activating β‐catenin/TCF pathway to promote cellular growth and inhibit apoptosis. © 2008 Wiley‐Liss, Inc.
α2‐Agonists as analgesic agents
Authors: Giovannoni Maria Paola , Ghelardini Carla , Vergelli Claudia , Dal Piaz Vittorio
Published: August 2008

It is well known that norepinephrine is involved in the control of pain by modulating pain‐related responses through various pathways. α2‐Adrenergic agonists have a well‐established analgesic profile and, in the recent years, have found a wider application, in particular as adjunct to anesthetics and analgesics in perioperative settings. This review analyzes the α2‐agonists currently in clinical use, starting from the prototype Clonidine, as well as the most promising and studied molecules. In addition, an overview of the imidazoles, imidazolines, and hydroxyethyl‐thioureas derivatives published in both the open and patented literature is presented, providing chemical description and pharmacological data. Finally, the most commonly α2‐agonists used in veterinary medicine are described. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 2, 339–368, 2009
Preparation of two kinds of porphyrin‐functionalized polymeric materials based on poly(glyceryl methacrylate)
Authors: Gao Baojiao , Zhang Yan , Wang Ruixin , Guo Haopeng
Published: August 2008

Poly(glyceryl methacrylate) (PGMA) was reacted with meso‐tetra(4‐hydroxylphenyl)porphyrin (THPP) in a homogeneous system via the ring opening reaction between epoxy and hydroxyl groups, which exist on the side chain of PGMA and the outside ring of THPP, respectively. Porphyrin‐functionalized PGMA with line‐type (denoted as HPP‐PGMA), on whose side chains hydroxylphenyl porphyrin (HPP) was bonded, was obtained. Grafting particles PGMA/SiO2 were also reacted with THPP, and the porphyrin‐immobilized particles (denoted as HPP‐PGMA/SiO2), on which HPP was supported, were produced. The above two target products were characterized using spectroscopy methods, such as infrared (IR), nuclear magnetic resonance (1H‐NMR), electronic absorption, and fluorescence emission. The effects of various factors on the bonding and immobilization reactions of HPP were studied in detail. The experimental results show that the soluble HPP‐PGMA has all the spectral characteristics of porphyrins and the absorption or emission intensity is increased with the increase in the bonding degree of HPP. In the preparation process of HPP‐PGMA, in order to avoid the occurrence of the crosslinking reaction and to obtain HPP‐PGMA with complete line‐type, the catalyst should be selected and the reaction time should be controlled. NaHCO3 is an appropriate catalyst. In the immobilization process of HPP on the grafting particle PGMA/SiO2, the greater the used amount of the catalyst triethylamine (TEA), the more rapid is the rate of ring opening reaction, resulting in higher immobilization amount of HPP. Besides, the immobilization amount of HPP is increased with the enhancement of the reaction temperature. Copyright © 2008 John Wiley & Sons, Ltd.
Shape memory fiber spun with segmented polyurethane ionomer
Authors: Zhu Yong , Hu Jinlian , Lu Jing , Yeung Lap Yan , Yeung Kwok‐wing
Published: August 2008

The effect of cationic groups within hard segments on shape memory polyurethane (SMPU) fibers was studied and the cyclic tensile testing was conducted to assess the shape memory effect. Mechanical properties, hard segment crystallization, and dynamic mechanical properties of SMPU ionomer fibers composed of 1,4‐butanediol (BDO), N‐methyldiethanolamine (NMDA), 4,4′‐methylenebis(phenyl isocyanate) (MDI), and poly(butylene adipate)diol (PBA) were investigated using a universal tensile tester, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The results demonstrate that only 2 wt% NMDA can significantly change the glass transition temperature of the soft segment phase. DSC shows that the ionic group within hard segments can facilitate the crystallization of hard segments in unsteamed SMPU ionomer fibers. But for steamed fiber specimens, this effect is insignificant. Moreover, the ionic groups in hard segments with different hard segment contents (HSC) have different effects. In unsteamed fibers with 64 wt% HSC, 2 wt% NMDA increases the glass transition of soft segments from 63.5 to 70.6°C. However, in fibers with 55 wt% HSC, the glass transition temperature is lowered from 46.7 to 33.5°C. The post‐treatment, high‐pressure steaming is an effective way to remove the internal stress and subsequently improve the dimensional stability of SMPU ionomer fibers. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and characterization of metronidazole‐loaded chitosan nanoparticles for drug delivery application
Authors: Elzatahry A. A. , Eldin M. S. Mohy
Published: August 2008

This study describes the preparation of mucoadhesive chitosan nanoparticles containing metronidazole (MZ) intended for colon‐specific delivery. The chitosan nanoparticles were prepared by the ionic gelation method and their in vitro properties were studied. The release profiles of MZ from the nanoparticles were determined by UV–Vis absorption measurement at λmax 278 nm. Scanning electron microscopy was used for morphology observation. The nanoparticles exhibited mucoadhesive properties, which diminished with increasing drug content. The nanoparticles with a particle size range between 200 and 300 nm exhibited excellent mucoadhesive properties. The results show that the formulated nanoparticles have succeeded in controlling the release of MZ over a 12‐hr period. In conclusion, the release of MZ was found to be dependent upon the composition of the nanoparticles, the ratio of the components and possible particle size, as well as bioadhesive ability. Copyright © 2008 John Wiley & Sons, Ltd.
Utility of FDG‐PET/CT in the follow‐up of neuroblastoma which became MIBG‐negative
Authors: Colavolpe Cécile , Guedj Eric , Cammilleri Serge , Taïeb David , Mundler Olivier , Coze Carole
Published: August 2008

We report on the case of a 10‐month‐old female infant with a metastatic neuroblastoma which became MIBG‐negative at time of relapse. We discuss the different hypothesis associated with this particular outcome, and the potential utility of FDG‐PET as an alternative to follow up the residual disease at this stage. Pediatr Blood Cancer 2008;51:828–831. © 2008 Wiley‐Liss, Inc.
Bordetella holmesii bacteremia in sickle cell disease
Authors: McCavit Timothy L. , Grube Steve , Revell Paula , Quinn Charles T.
Published: August 2008

Patients with sickle cell disease (SCD) have an increased risk of invasive bacterial infection because of hyposplenism. Bordetella holmesii is a recently described Gram‐negative coccobacillus with an apparent predilection for asplenic hosts. We report two patients with SCD and B. holmesii bacteremia. Fastidious growth in culture and a typically uncomplicated clinical course distinguish B. holmesii infection from other invasive bacterial infections in SCD. Providers for patients with SCD should be aware of this pathogen and ensure that their microbiology laboratories are capable of isolating and identifying this organism. Pediatr Blood Cancer 2008;51:814–816. © 2008 Wiley‐Liss, Inc.
Plethysmographic lung volumes in normal chilean children and adolescents
Authors: Caussade Solange , Pulgar Dahiana , Vega‐Briceno Luis , Viviani Paola , Diaz Carla , Contreras Ilse , Sanchez Ignacio
Published: August 2008

Introduction

Plethysmographic measurement is the most reliable method for evaluating lung volumes in children. Current published normative data are based on studies in primarily Caucasian children.

Objectives

To establish Chilean normal values with new reference equations and to compare these results with previously published data.

Subjects and Methods

Lung function was measured [slow vital capacity (SVC), inspiratory capacity (IC), expiratory reserve volume (ERV), functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), and RV/TLC] in 245 healthy Chilean school children and adolescents, using spirometry and plethysmography; 123 girls and 122 boys were studied, aged 7–18 years.

Results

Almost all variables of pulmonary volume differed between boys and girls (P < 0.05). Z scores were significantly higher than zero in all age groups when compared with predicted values. We present predictive exponential equations for each variable of static lung volume; all of these variables had a strong correlation with height, but not weight.

Normal values of lung volumes of Chilean school children and adolescents are significantly higher than the current predictive values. These differences may be related to differences in anthropometric characteristics. We recommend using these data in our population and postulate that Latin‐American populations like ours may have similar lung volumes. Pediatr Pulmonol. 2008; 43:866–873. © 2008 Wiley‐Liss, Inc.
Effectiveness of home treatment for patients with cystic fibrosis: The intravenous administration of antibiotics to treat respiratory infections
Authors: Termoz A. , Touzet S. , Bourdy S. , Decullier E. , Bouveret L. , Colin C. , Nove‐Josserand R. , Reix P. , Cracowski C. , Pin I. , Bellon G. , Durieu I.
Published: August 2008

Patients with cystic fibrosis (CF) experience repeated infectious respiratory exacerbations leading to a continuous decline in lung function. The exacerbations are treated in hospital or at home. Our aim was to compare the clinical outcome for patients undergoing intravenous antibiotic treatment either in hospital or at home. A retrospective 10‐year study was performed in four regional CF Centers. The outcome measures were percentage changes in forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC) and weight for age z‐score (WZS). FEV1, FVC, and WZS changes were calculated for the entire study period and for each course. A total of 1,164 courses were analyzed. For each course, the mean improvement in FEV1 and FVC was significantly higher when performed in hospital than when performed at home (P < 0.05). FEV1 and FVC values were 10.2%, 9.5% respectively in the hospital group and 7.3%, 6.8% in the home group. A total of 153 patients were analyzed (51 inpatients matched to 102 patients treated at home). The two groups had no significant differences in any outcome variable at baseline. The mean variation per year in FEV1 was greater in the hospital group versus the home group (−0.4% vs. −1.8%; P = 0.03). The mean variation per year in WZS was greater in the hospital group versus the home group (P < 0.01). Clinical outcome, as defined by spirometric parameters and body weight, was better after a course of treatment in hospital than after a home treatment. This benefit was maintained throughout of the study period. Pediatr Pulmonol. 2008; 43:908–915. © 2008 Wiley‐Liss, Inc.
Obstructive sleep disordered breathing in children: Beyond adenotonsillectomy
Authors: Praud Jean‐Paul , Dorion Dominique
Published: August 2008

Traditionally, adenotonsillectomy (AT) has long been the treatment of choice for obstructive sleep disordered breathing (SDB) in children. AT is usually considered a safe procedure, which cures 80% of children with SDB. Accumulated data have however challenged this overly simplistic view. Indeed, AT is invariably associated with significant morbidity, post‐operative pain, and a mortality rate which, though low, cannot be ignored. In addition, aside from a recurrence of SDB at adolescence in an unknown percentage of cases, some recent results suggest that complete SDB cure is not achieved in as much as 75% of cases after AT. Interestingly, several treatment options have been recently proposed for replacing or complementing AT. Continuous positive airway pressure (CPAP) is now suggested in children with remaining SDB after AT; however, compliance and suitability of equipment remain important hurdles, especially in small children and infants. Anti‐inflammatory treatments, including nasal glucocorticoids and/or the anti‐leukotriene montelukast, appear to hold great promise. Finally, orthodontic treatments are an appealing option, with recent results in children suggesting that it is possible to improve or perhaps even cure SDB in a durable manner by enlarging the nasal passages and/or the oropharyngeal airspace. In conclusion, while we are currently in the midst of an exciting time with several new treatments being developed for childhood SDB, randomized controlled trials are urgently needed to delineate their indications. In the meantime, it appears that systematic detection of orthodontic anomalies and better collaboration with maxillofacial specialists, including orthodontists and/or dentists, is needed for deciding the best treatment options for childhood SDB. Pediatr Pulmonol. 2008; 43:837–843. © 2008 Wiley‐Liss, Inc.
On the analysis of some orbital contributions to the current density in circulenes
Authors: Monaco Guglielmo , Zanasi Riccardo
Published: August 2008

According to the ipsocentric method, the current density stems from a sum of rotationally and translationally allowed transitions: translationally allowed transition are diatropic and rotationally allowed transition must be prevailingly paratropic. Applying this method to circulenes, we show that it can be used, together with simple Hückel theory, to design systems with localized currents on the rim. More importantly, we report the current density maps of coronene2+ and coronene2−. In these systems, a single rotational contribution gives both diatropic and paratropic circulations. This finding has been interpreted by a simple model based on the orbitals of the subsystem, which are the hub and the rim. It turns out that, in such cases, simple inspection of the Hückel orbitals is sufficient to predict the relative tropicities on the rim and the hub. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Preformed pair induced quantum phase transition in fulleride superconductivity
Authors: Squire Richard H. , March Norman H.
Published: August 2008

There continues to be enormous interest in the BCS to BEC transition. While the BCS and BEC “end points” seem to be well‐established, in the intermediate region—home to fulleride and high temperature superconductors—considerable extrapolation of the models must be done as there still is no exact theory. Last year we reported a revealing reinterpretation of the Boson–Fermion model (BFM) by comparing it to the “cold” atom formulation. While the ground and singly excited states appear to remain continuous in all models we have examined, the collective modes due to a Feshbach resonance (tuned by doping) cause a breakdown of the Migdal theorem, thereby transforming the nature of the superconductivity. As a result of vertex corrections there is a fundamental change in the nature of the superconductivity due to the formation of “preformed pairs” as the previously suggested location (Squire and March, Int J Quantum Chem 2007, 107, 3013) of a quantum critical point in the fulleride phase diagram is passed. The result is a quantum phase transition between BCS and BEC superconductivity (SC) in the BFM. We discuss features of the resonance and the experimentally observed preformed pair formation in fullerides, essential to the BFM, and often speculated since the work of Nozieres and Schmitt–Rink (J Low Temp Phys 1985, 59, 980). Here we present arguments to establish a model of the preformed pair which can be favorably compared with a circular charge density wave (CDW) isolated on a fulleride molecule due to Coulomb splitting of the Jahn–Teller active Hg vibrational modes. Our conclusions are: (1) the doping of two electrons into triply degenerate t1u orbitals results in the experimentally observed singlet state (CDW); and (2) this CDW (preformed pair) results in suppression of BCS SC and enables the Feshbach resonance. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Theoretical studies on effects of hydrogen bonds attaching to cysteine ligands on 4Fe‐4S clusters
Authors: Kitagawa Y. , Shoji M. , Saito T. , Nakanishi Y. , Koizumi K. , Kawakami T. , Okumura M. , Yamaguchi K.
Published: August 2008

The effect of hydrogen bonds attaching to sulfur atoms of cysteine ligands on 4Fe‐4S cluster is examined by using UB3LYP method. Calculated results indicate that an existence of the hydrogen bonds scarcely changes SOMO‐SUMO gap, shapes of Kohn‐Sham orbitals, and magnetic interactions between Fe ions, although it stabilizes Kohn‐Sham orbital energies of SOMO and SUMO about 1.0 eV. And they also make a reduced state stable in comparison with an oxidized state. In addition, the point charges of +0.1e (e: elementary electric charge) at the position of the hydrogen atoms give almost same results to the hydrogen bonds quantitatively. The results suggest that a positive environment from the hydrogen bonds around the clusters is important for a redox potential of 4Fe‐4S clusters. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Computational modeling of inclusion complexes of β‐cyclodextrin with enantiomers of salsolinol, N‐methyl‐salsolinol, and 1‐benzyl‐tetrahydroisoquinoline
Authors: Huang Ming‐Ju , Quan Zhe , Liu Yi‐Ming
Published: August 2008

Capillary electrophoresis with β‐CD as a chiral selector has successfully separated the two enantiomers of salsolinol, N‐methyl‐salsolinol, and 1‐benzyl‐tetrahydroisoquinoline (BTIQ). The migration times of each enantiomer in capillary electrophoresis reflect the stability of their β‐CD inclusion complexes. This paper reports a computational modeling study of the inclusion complexes of β‐cyclodextrin (β‐CD) with salsolinol, N‐methyl‐salsolinol, and BTIQ by using PM3 (Parametric Method 3) semiempirical molecular orbital calculations and the ONIOM hybrid method. Two types of the inclusion complexes, cis‐ and trans‐orientations, are considered for each enantiomer of the guest molecules, salsolinol, N‐methyl‐salsolinol, and BTIQ. In the cis‐orientation, the nitrogen in the salsolinol, N‐methyl‐salsolinol, and BTIQ points toward the secondary hydroxyls of the β‐CD, while in the trans‐orientation, the nitrogen in salsolinol, N‐methyl‐salsolinol, and BTIQ points toward the primary hydroxyls of the β‐CD. We found that the stabilization energies of these inclusion complexes from these PM3 and ONIOM different methods correlate very well with the migration order deduced from the study of capillary electrophoretic separation. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Structural evaluation of the glucuronides of morphine and formoterol using chemical derivatization with 1,2‐dimethylimidazole‐4‐sulfonyl chloride and liquid chromatography/ion trap mass spectrometry
Authors: Salomonsson Matilda Lampinen , Bondesson Ulf , Hedeland Mikael
Published: August 2008

For the first time chemical derivatization of isomeric drug glucuronides with 1,2‐dimethylimidazole‐4‐sulfonyl chloride (DMISC) has been successfully applied as a tool for determining the site of conjugation. This provides a way to differentiate between glucuronide isomers containing aliphatic and phenolic hydroxyl groups. The analyses were performed with liquid chromatography/electrospray ion trap mass spectrometry (LC/ESI‐MSn). DMISC has previously been shown to react selectively with phenols in estrogens, thus improving sensitivity in ESI‐MS. The model compounds selected for this study were commercially available standards of formoterol, morphine, morphine‐3‐glucuronide (M3G), and morphine‐6‐glucuronide (M6G). Formoterol glucuronides were produced with an enzymatic method in house. Both formoterol and morphine possess one phenolic and one aliphatic hydroxyl group where glucuronidation could take place. The product ion mass spectra of the native morphine glucuronides were indistinguishable due to the initial neutral loss of monodehydrated glucuronic acid (176 u). However, a significant difference between the isomers was observed with DMISC derivatization, as only the form with a free phenol, M6G, gave a detectable reaction product. Formoterol formed two detectable glucuronide isomers in the enzymatic reaction. Their respective sites of conjugation could not be directly determined from the product ion spectra. Reaction with DMISC, however, gave a detectable product with only one of the isomers. Based on previous experience of the preferred DMISC reactions with phenols, and interpretation of the fragmentation pattern of the derivative, it was concluded that the reactive isomer had a free phenol, and was thus conjugated on the aliphatic chain. Copyright © 2008 John Wiley & Sons, Ltd.