bluuebunny/crossref_metadata_2025 huggingface dataset:
Is dyslexia necessarily associated with negative feelings of self‐worth? A review and implications for future research
Authors: Burden Robert
Published: July 2008

This paper will provide an overview of research in the past 20 years into the relationship between dyslexia and various aspects of self‐perception, including self‐concept, self‐esteem, self‐efficacy and locus of control. Problems are identified relating to the measurement of some of the most widely used constructs, as is the need for more precise identification of key variables relating to them. Critical issues concerning the assumptions that can be drawn from largely correlational data are highlighted also. The conclusion is drawn that an alternative approach to research in this area is required to enhance our understanding of how those suffering from learning disabilities of a dyslexic nature develop a positive or negative sense of identity. Suggestions are made as to how this can be achieved by drawing upon attribution theory and other aspects of social psychology. Copyright © 2008 John Wiley & Sons, Ltd.
Depression and excess mortality: evidence for a dose response relation in community living elderly
Authors: Schoevers R. A. , Geerlings M. I. , Deeg D. J. H. , Holwerda T. J. , Jonker C. , Beekman A. T. F.
Published: July 2008

Context

Depression is associated with an increased mortality risk. It is not known to what extent depression characteristics such as severity and length of exposure to depression contribute to the association with excess mortality.

Objectives

To investigate the association between depression severity and duration with mortality in community‐living elderly.

Design

Two‐wave prospective cohort study with 10‐year follow‐up of vital status. Assessment of depression at baseline and at three year follow‐up (GMS‐AGECAT). Cox proportional hazards analyses of mortality with depression according to severity and length of exposure, adjusted for demographic variables, physical illnesses, cognitive decline and functional disabilities.

Setting and participants

Randomly selected cohort of 3 746 non‐demented older community‐living persons in the city of Amsterdam.

Main outcome measures

Excess mortality of both the baseline cohort, and of non‐demented subjects participating in both assessments (n = 1989).

Results

Both moderate (MHR 1.29, 95% CI 1.03–1.61) and severe depression (MHR 1.34, 95% CI 1.07–1.68) predicted 10‐year mortality after multivariate adjustment. Chronic depression was associated with a 41% higher mortality risk in 6‐year follow‐up compared to subjects without depression.

Conclusions

Severity and chronicity of depression are associated with a higher mortality risk. In combination with other findings this is suggestive of a causal relationship and may have implications for both preventive and treatment strategies of late‐life depression. Copyright © 2008 John Wiley & Sons, Ltd.
Characteristics of help‐seeking behaviour in subjects with subjective memory complaints at a memory clinic: a case‐control study
Authors: Ramakers Inez H. G. B. , Visser Pieter Jelle , Bittermann Arnold J. N. , Ponds Rudolf W. H. M. , van Boxtel Martin P. J. , Verhey Frans R. J.
Published: July 2008

Objective

Memory complaints in the absence of objective test impairments are common. Only a subset of these subjects seeks medical attention for these complaints. The aim of the present study was to investigate which factors determine why people with subjective memory complaints (SMC) seek medical attention.

Methods

Thirty‐three cases with SMC from a memory clinic were compared to 85 control subjects with SMC from a population‐based study who did not seek help for their complaints. We investigated whether cases differed from controls with respect to the following: depressive and anxiety symptoms (SCL‐90), extraversion and neuroticism (EPQ), meta‐memory (MIA), quality of life (SF‐36), changes in memory and daily functioning according to a relative (DECO), life‐changing events, and a family history of dementia.

Results

Cases with SMC who seek medical attention, scored lower on memory self‐efficacy and quality of life. They were more often worried due to a positive family history of dementia by comparison to the control subjects. Relatives of cases reported more deterioration in daily functioning than relatives of controls. Both the cases and control subjects had similar levels of depressive and anxiety symptoms, as well as levels of extraversion and neuroticism.

Conclusion

Lower memory self‐efficacy and quality of life, deterioration in daily functioning, and worries due to a positive family history for dementia are factors that determine why subjects with SMC seek medical attention. This information may be useful for the development of interventions for these subjects. Copyright © 2008 John Wiley & Sons, Ltd.
Selenoprotein P expression is controlled through interaction of the coactivator PGC-1α with FoxO1a and hepatocyte nuclear factor 4α transcription factors
Authors: Speckmann Bodo , Walter Philippe L. , Alili Lirija , Reinehr Roland , Sies Helmut , Klotz Lars-Oliver , Steinbrenner Holger
Published: July 2008

Selenoprotein P (SeP), the major selenoprotein in plasma, is produced mainly by the liver, although SeP expression is detected in many organs. Recently, we reported stimulation of SeP promoter activity by the forkhead box transcription factor FoxO1a in hepatoma cells and its attenuation by insulin. Here, we demonstrate that this translates into fine-tuning of SeP production and secretion by insulin. Overexpression of peroxisomal proliferator activated receptor-γ coactivator 1α (PGC-1α) enhanced the stimulatory effect of FoxO1a on SeP promoter activity. We identified a novel functional binding site for hepatocyte nuclear factor (HNF)-4α, termed hepatocyte nuclear factor binding element 1, in the human SeP promoter directly upstream of the FoxO-responsive element daf16-binding element 2 (DBE2). Point mutations in hepatocyte nuclear factor binding element 1 alone or together with DBE2 decreased basal activity and responsiveness of the SeP promoter to PGC-1α. Moreover, the PGC-1α-inducing glucocorticoid dexamethasone strongly enhanced SeP messenger RNA levels and protein secretion in cultured rat hepatocytes, whereas insulin suppressed the stimulation of both PGC-1α and SeP caused by dexamethasone treatment. In a brain-derived neuroblastoma cell line with low basal SeP expression, SeP transcription was stimulated by PGC-1α together with FoxO1a, and overexpression of HNF-4α potentiated this effect.

Conclusion:

High-level expression of SeP in liver is ensured by concerted action of the coactivator PGC-1α and the transcription factors FoxO1a and HNF-4α. Hence, the production of SeP is regulated similarly to that of the gluconeogenic enzyme glucose-6-phosphatase. As hepatic SeP production is crucial for selenium distribution throughout the body, the present study establishes PGC-1α as a key regulator of selenium homeostasis. (Hepatology 2008;48:1998-2006.)
Liver sinusoidal endothelial cells depend on mannose receptor-mediated recruitment of lysosomal enzymes for normal degradation capacity
Authors: Elvevold Kjetil , Simon-Santamaria Jaione , Hasvold Hege , McCourt Peter , Smedsrφd Bård , Sφrensen Karen Kristine
Published: July 2008

Liver sinusoidal endothelial cells (LSECs) are largely responsible for the removal of circulating lysosomal enzymes (LE) via mannose receptor (MR)-mediated endocytosis. We hypothesized that LSECs rely on this uptake to maintain their extraordinarily high degradation capacity for other endocytosed material. Circulatory half-life studies of 125I-cathepsin-D in MR knockout (MR−/−) and wild-type mice, and endocytosis studies in LSEC cultures, showed a total dependence on the MR for effective clearance of cathepsin-D. Radioiodinated formaldehyde-treated serum albumin, a ligand for the LSEC scavenger receptors, was used to study catabolism of endocytosed material in MR−/− and wild-type mice. The plasma clearance, liver uptake, and the starting point for release of degradation products to blood, were similar in both experimental groups, indicating normal endocytosis and intracellular transport of scavenger receptor ligands in MR−/− mice. However, the rate of formaldehyde-treated serum albumin catabolism in the liver of the MR deficient animals was reduced to approximately 50% of wild-type values. A similar reduction in intracellular degradation was recorded in LSEC cultures from MR−/− mice compared to wild-type controls. In accordance with this, MR−/− LSECs had markedly and significantly reduced enzyme activities for four out of five LE tested, i.e., cathepsin-D, α-mannosidase, β-hexosaminidase and arylsulfatase, but not acid phosphatase, compared to wild-type controls. Immunoblot analysis showed that the content of pro-cathepsin-D relative to total cathepsin-D in wild-type LSECs was less than one-fifth of that in hepatocytes, indicating lower endogenous LE production in the LSECs.

Conclusion:

We show for the first time that LSEC depend on MR-mediated recruitment of LE from their surroundings for effective catabolism of endocytosed macromolecules. (Hepatology 2008;48:2007–2015.)
Rationale for folate receptor alpha targeted therapy in “high risk” endometrial carcinomas
Authors: Brown Jones Monica , Neuper Christina , Clayton Amy , Mariani Andrea , Konecny Gottfried , Thomas M. Bijoy , Keeney Gary , Hartmann Lynn , Podratz Karl C.
Published: July 2008

Advanced and recurrent endometrial cancers account for the majority of deaths from this disease with limited therapeutic options. High grade, and nonendometrioid histology, pathologically characterize the endometrial tumors associated with adverse outcome and are classified as “high risk”. The identification of molecular prognostic factors that might be targeted for therapy among “high risk” endometrial cancers is an active area of investigation. We hypothesize that the FRα, highly expressed in endometrial cancer cells, is a potential target for this disease. Our objectives were to determine if FRα overexpression is associated with adverse prognostic factors and worse outcome. Three hundred and thirty‐two endometrial cancer cores were arrayed onto a tissue microarray and stained using a FRα‐specific monoclonal antibody. Staining was scored as absent or weak and moderate or strong. Forty‐one percent of 310 evaluable cases stained moderate/strong. Moderate/strong FRα staining was significantly associated with other poor prognostic factors including: advanced stage, nonendometrioid histology and high grade. An association was observed between moderate/strong FRα staining and recurrence (p < 0.0014). These findings support further exploring a role for FRα targeted approaches for therapy and diagnostics in endometrial cancer. © 2008 Wiley‐Liss, Inc.
Molecular characteristics and predictors of survival in patients with malignant neuroendocrine tumors
Authors: Arnold Christian N. , Nagasaka Takeshi , Goel Ajay , Scharf Iris , Grabowski Patricia , Sosnowski Andrea , Schmitt‐Gräff Annette , Boland C. Richard , Arnold Rudolf , Blum Hubert E.
Published: July 2008

To better understand the molecular pathogenesis of neuroendocrine tumors (NET), we investigated the molecular and clinical characteristics of malignant poorly differentiated colorectal NET and compared these findings with sporadic CRC and well‐differentiated benign and malignant fore‐/midgut NET. Tumors were analyzed and correlated for microsatellite instability (MSI) and the CpG island methylator phenotype (CIMP). NET were scored for proliferation using Ki‐67. A total of 34 malignant poorly differentiated colorectal NET, 38 well‐differentiated benign and malignant fore‐/midgut‐NET and 150 sporadic colorectal cancers (CRC) with known MSI status were investigated. Among the sporadic CRC, CIMP was significantly correlated with MSI‐high (MSI‐H) (p < 0.001). Of the 34 colorectal NET, 0/1 of the MSI‐H, 3/5 (60%) of the MSI‐L and 13/19 (68%) of the MSS tumors were CIMP+ (p = 0.17). Of the fore‐/midgut‐NET, none was MSI‐H. 20/34 (59%) colorectal NET vs. 11/38 (29%) fore‐/midgut‐NET were CIMP+ (p = 0.01). The Ki‐67 index was significantly higher in poorly differentiated colorectal NET compared to the less malignant fore‐/midgut‐NET (p < 0.0001). Besides the location in the colon, Ki‐67 predicted poor outcome in NET (p < 0.0001). CIMP status did not affect survival. In NET, p16 methylation predicted a poor outcome (p = 0.0004). We conclude that molecular pathogenesis in sporadic CRC and poorly differentiated colorectal NET is different despite some similarities. Main differences between malignant well‐differentiated and poorly differentiated NET are the Ki‐67 proliferation rate and differential methylation in tumor‐associated genes. Predictors of a poor outcome in patients with NET are poor differentiation, a high Ki‐67 index and p16 methylation. © 2008 Wiley‐Liss, Inc.
Cancer testis antigen expression in gastrointestinal stromal tumors: New markers for early recurrence
Authors: Perez Daniel , Herrmann Thomas , Jungbluth Achim A. , Samartzis Pierre , Spagnoli Giulio , Demartines Nicolas , Clavien Pierre‐Alain , Marino Silvia , Seifert Burkhardt , Jaeger Dirk
Published: July 2008

Cancer testis antigens (CTAs) are expressed in a variety of malignant tumors but not in any normal adult tissues except germ cells and occasionally placenta. Because of this tumor‐associated pattern of expression, CTAs are regarded as potential vaccine targets. The expression of CTAs in gastrointestinal stromal tumors (GIST) has not been analyzed systematically previously. The present study was performed to analyze the expression of CTA in GIST and to determine if CTA expression correlates with prognosis. Thirty‐five GIST patients were retrospectively analyzed for their expression of CTAs by immunohistochemistry using the followingmonoclonal antibodies (mAb/antigen): MA454/MAGE‐A1, M3H67/MAGE‐A3, 57B/MAGE‐A4, CT7‐33/MAGE‐C1 and E978/NY‐ESO‐1. Fourteen tumors (40%) expressed 1 or more of the 5 CTAs tested. Fourteen percent (n = 5/35) were positive for MAGE‐A1, MAGE‐A3 or MAGE‐A4, respectively. Twenty‐six percent (n = 9/35) stained positive for MAGE‐C1 and 20% (n = 7/35) for NY‐ESO‐1. A highly significant correlation between CTA expression and tumor recurrence risk was observed (71% vs. 29%; p = 0.027). In our study population, the high‐risk GIST expressed CTAs more frequently than low‐risk GIST (p = 0.012). High‐risk GISTs which stained positive for at least 1 CTA, recurred in 100% (n = 25) of the cases. This is the first study analyzing CTA expression in GIST and its prognostic value for recurrence. The CTA staining could add information to the individual patient prognosis and represent an interesting target for future treatment strategies. © 2008 Wiley‐Liss, Inc.
Cytocompatibility of a free machining titanium alloy containing lanthanum
Authors: Feyerabend Frank , Siemers Carsten , Willumeit Regine , Rösler Joachim
Published: July 2008

Titanium alloys like Ti6Al4V are widely used in medical engineering. However, the mechanical and chemical properties of titanium alloys lead to poor machinability, resulting in high production costs of medical products. To improve the machinability of Ti6Al4V, 0.9% of the rare earth element lanthanum (La) was added. The microstructure, the mechanical, and the corrosion properties were determined. Lanthanum containing alloys exhibited discrete particles of cubic lanthanum. The mechanical properties and corrosion resistance were slightly decreased but are still sufficient for many applications in the field of medical engineering. In vitro experiments with mouse macrophages (RAW 264.7) and human bone‐derived cells (MG‐63, HBDC) were performed and revealed that macrophages showed a dose response below and above a LaCl3 concentration of 200 μM, while MG‐63 and HBDC tolerated three times higher concentrations without reduction of viability. The viability of cells cultured on disks of the materials showed no differences between the reference and the lanthanum containing alloy. We therefore propose that lanthanum containing alloy appears to be a good alternative for biomedical applications, where machining of parts is necessary. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Surfaces having dual fibrinolytic and protein resistant properties by immobilization of lysine on polyurethane through a PEG spacer
Authors: Chen Hong , Zhang Yanxia , Li Dan , Hu Xiaoyang , Wang Liang , McClung W. Glenn , Brash John L.
Published: July 2008

The objective of this work is to develop a blood contacting surface that possesses both resistance to nonspecific protein adsorption and clot lysing properties. Chemical modification of a polyurethane (PU) surface with poly(ethylene glycol) (PEG); and lysine was used to create a plasminogen‐binding potentially fibrinolytic surface. The preparation involves modification of the PU surface with dihydroxy PEG, reaction of the unreacted distal OH with N,N′‐disuccinimidyl carbonate (DSC) to produce a PU‐PEG‐NHS surface, followed by conjugation of ε‐amino‐protected lysine (H‐Lys(t‐BOC)‐OH) by reaction of the α‐amino group with the NHS and deprotection. The result is a lysine‐derivatized surface in which the ε‐amino groups of the lysine are free to participate in binding plasminogen and tissue plasminogen activator (t‐PA). Surfaces were characterized by X‐ray photoelectron spectroscopy (XPS) and contact angle measurements. Protein adsorption experiments showed that nonspecific protein adsorption was greatly reduced on these surfaces and that they adsorbed significant quantities of plasminogen from plasma. After incubation with plasma and treatment with t‐PA the surfaces were able to dissolve nascent plasma clots formed around them. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Mono‐functional aminosilanes as primers for peptide functionalization
Authors: Pegg Elise C. , Walker Gavin S. , Scotchford Colin A. , Farrar David , Grant David
Published: July 2008

When covalently attaching biomolecules to surfaces such as titanium, trifunctional silanes are commonly used as primers to produce surface amine groups. However, these primed surfaces are rarely uniform in structure due to networking of the silane. Mono‐functional aminosilanes may result in more uniform structures, although their long‐term stability and effect on osteoblast cell responses are possible issues for orthopedic applications. This study examines for the first time the optimization of peptide coupling to titanium using mono‐functional aminosilane reaction chemistry. The resultant surface topography, chemistry, and thicknesses were characterized showing improved surface uniformity compared with trifunctional silanized surfaces. The stability of the coatings was examined over a period of 8 days in environments of varying pH, temperature, and humidity. In addition, human osteosarcoma (HOS) cell adhesion and spreading on the samples was examined; adhesion was minimal on silanized surfaces, but after functionalization with cysteine the cell density was greater than the titanium control and showed no overall detrimental effect on initial cell responses. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Genetic characterization of captive Cuban crocodiles (Crocodylus rhombifer) and evidence of hybridization with the American crocodile (Crocodylus acutus)
Authors: Weaver Jeremy P. , Rodriguez David , Venegas‐Anaya Miryam , Cedeño‐Vázquez José Rogelio , Forstner Michael R.J. , Densmore Llewellyn D.
Published: July 2008

There is a surprising lack of genetic data for the Cuban crocodile (Crocodylus rhombifer), especially given its status as a critically endangered species. Samples from captive individuals were used to genetically characterize this species in comparison with other New World crocodilians. Partial mitochondrial sequence data were generated from cyt‐b (843 bp) and the tRNAPro‐ tRNAPhe‐D‐loop region (442 bp). Phylogenetic analyses were performed by generating maximum parsimony, maximum likelihood, and Bayesian‐based topologies. In addition, in an effort to identify species‐specific alleles, ten polymorphic microsatellite loci were genotyped. Distance and model‐based clustering analyses were performed on microsatellite data, in addition to a model‐based assignment of hybrid types. Both mitochondrial and nuclear markers identified two distinct C. rhombifer genetic sub‐clades (α and β); and microsatellite analyses revealed that most admixed individuals were F2 hybrids between C. rhombifer‐α and the American crocodile (C. acutus). All individuals in the C. rhombifer‐β group were morphologically identified as C. acutus and formed a distinct genetic assemblage. J. Exp. Zool. 309A:649–660, 2008. © 2008 Wiley‐Liss, Inc.
The effect of endosomal escape peptides on in vitro gene delivery of polyethylene glycol‐based vehicles
Authors: Moore Nicole M. , Sheppard Clayton L. , Barbour Tiffany R. , Sakiyama‐Elbert Shelly E.
Published: July 2008

Background

With recent progress in gene therapy clinical trials, there is an even greater demand to advance the development of nonviral gene delivery vehicles. We have previously developed poly(ethylene glycol) (PEG)‐based vehicles with transfection efficiency similar to polyethyleneimine and low cytotoxicity. It was hypothesized that conjugating endosomal escape peptides (EEPs) to PEG‐based vehicles would further increase their transfection efficiency. The present study aimed to determine how two different EEPs, INF7 and H5WYG, which destabilize the endosomal membrane at different pHs, affect the efficiency of PEG‐based vehicles.

Methods

INF7 and H5WYG were conjugated to PEG‐tetraacrylate (PEG‐TA) via a Michael‐type addition at the desired molar ratios. The pH‐dependent membrane lytic activity, transfection efficiency, particle size, zeta potential, and endosomal escape kinetic rate constants were determined.

Results

Fusogenic peptides, INF7 and H5WYG, showed pH‐dependent membrane lytic activity when conjugated to PEG‐TA. The highest membrane lytic activity of PEG‐INF7 and PEG‐H5WYG conjugates occurred at pH 5 and 5.5, respectively. Coupling one INF7 peptide to PEG‐DNA binding peptide (DBP) vehicles increased the transfection efficiency ten‐fold and showed greater transfection efficiency than PEG‐DBP vehicles coupled with H5WYG peptide. Fitting a first‐order kinetic model to the average intracellular pH of the vehicle/DNA particles over time determined that coupling EEPs to PEG‐DBP vehicles increased the endosomal escape rate constant by two orders of magnitude.

Conclusions

Endosomal escape is a key step in nonviral cellular trafficking and thus the transfection efficiency of nonviral vehicles can be increased by targeting release of DNA from the endosome with EEPs. Copyright © 2008 John Wiley & Sons, Ltd.
Optimization of a door seal structure of a microwave oven using a FDTD method
Authors: Rocha Ana Maria , Facão Margarida , Sousa João Pedro , Viegas António
Published: July 2008

The optimum door seal configuration to prevent radiation leakage from a microwave oven is still a manufacturing concern. Here, we propose a numerical algorithm to simulate the radiation propagation along a door seal structure using the finite‐difference time domain method, which is used for a priori shielding efficiency tests. The results agree with experimental data. The critical dimensions of the choke structure were found and high shielding is anticipated for a simpler choke structure. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of the autumn Iberian precipitation from long‐term datasets: comparison between observed and hindcasted data
Authors: Valero F. , Martín M. L. , Sotillo M. G. , Morata A. , Luna M. Y.
Published: July 2008

The present paper is focused on the analysis of the characterization of the autumn precipitation regime over the Iberian Peninsula. To this aim, different long‐term, observed, hindcasted and reanalysed datasets are used to analyse the 41‐year (1961–2001) time period. A long‐term high‐resolution precipitation database, derived from more than 4000 in situ observational stations, is used to characterize the rainfall regime. This observational data, used as a reference, allows the verification of the realism of different existing long‐term hindcasted and reanalysed products. These verification and comparison exercises were carried out with the autumn monthly hindcasted data derived from the high‐resolution Mediterranean Hindcast of Dynamic Processes of the Ocean and Coastal Areas of Europe (HIPOCAS) database, as well as the NCEP and ERA global reanalysis data. The characterization of autumn Iberian rainfall is carried out, both in terms of spatial and time variability, by means of spatial distribution of different statistics and a principal component analysis (PCA), as well as through an analysis based on wavelet methodology. The statistical comparative analysis between the HIPOCAS and the observed precipitation data shows a noticeable agreement existing between both datasets, highlighting that the Mediterranean HIPOCAS hindcast database is a useful tool that is able to accurately reproduce and largely capture the main spatial and time features that regionally configure the Iberian rainfall regime along the studied 41‐year period. Moreover, it is verified that the hindcasted HIPOCAS data notably improves the characterization of the autumn Iberian precipitation provided by the aforementioned global reanalysis products, asserting that the HIPOCAS precipitation dataset can well be used in regional studies related to hydrometeorology, statistical downscaling and climate variability. Copyright © 2008 Royal Meteorological Society
Raman spectroscopic study of the tellurite minerals: emmonsite Fe23+Te34+O9·2H2O and zemannite Mg0.5[Zn2+Fe3+(TeO3)3]4.5H2O
Authors: Frost Ray L. , Dickfos Marilla J. , Keeffe Eloise C.
Published: July 2008

Raman spectroscopy has been used to study zemannite Mg0.5[Zn2+Fe3+(TeO3)3]4.5H2O and emmonsite Fe23+Te34+O9·2H2O. Raman bands for zemannite and emmonsite, observed at 740 and 650 cm−1 and at 764 and 788 cm−1, respectively, are attributed to the ν1 (TeO3)2− symmetric stretching mode. The splitting of the symmetric stretching mode for emmonsite is in harmony with the results of X‐ray crystallography which shows three non‐equivalent TeO3 units in the crystal structure. Two bands at 658 and 688 cm−1 are assigned to ν3 (TeO3)2− anti‐symmetric stretching modes. Raman bands observed at 372 and 408 cm−1 for zemannite and 397 and 414 cm−1 for emmonsite are attributed to the (TeO3)2−ν2(A1) bending mode. The two Raman bands at 400 and 440 cm−1 for emmonsite are ascribed to the ν4(E) bending modes, while the band at 326 cm−1 is due to the ν2(A1) bending vibration. Copyright © 2008 John Wiley & Sons, Ltd.
Structural conformations and electronic interactions of the natural product, oroxylin: a vibrational spectroscopic study
Authors: Abraham Jose P. , Sajan D. , Mathew Joseph , Hubert Joe I. , George V. , Jayakumar V. S.
Published: July 2008

The oroxylin, 5,7‐dihydroxy 6‐methoxy flavone is a potent natural product extracted from ‘Vitex peduncularis’. Density functional theory (DFT) at B3LYP/6‐311G(d,p) level has been used to compute energies of different conformers of oroxylin to find out their stability, the optimized geometry of the most stable conformer and its vibrational spectrum. The conformer ORLN‐1 with torsion angles 0, 180, 180 and 0 degrees, respectively, for H13O12C6C5, H14O10C4C5, H13O12C6C5 and H14O10C4C5 is found to be most stable. The optimized geometry reveals that the dihedral angle φ between phenyl ring B and the chrome part of the molecule in − 19.21° is due to the repulsive force due to steric interaction between the ortho‐hydrogen atom H29 of the B ring and H18 of the ring C (H29·H18 = 2.198 Å). A vibrational analysis based on the near‐infrared Fourier transform(NIR‐FT) Raman, Fourier transform‐infrared (FT‐IR) and the computed spectrum reveals that the methoxy group is influenced by the oxygen lone pair‐aryl pz orbital by back donation. Hence the stretching and bending vibrational modes of the methoxy group possess the lowest wavenumber from the normal values of methyl group. The carbonyl stretching vibrations have been lowered due to conjugation and hydrogen bonding in the molecules. The intramolecular H‐bonding and nonbonded intramolecular interactions shift the band position of O10H14 and O12H13 stretching modes, which is justified by DFT results. Copyright © 2008 John Wiley & Sons, Ltd.
Vibrational spectroscopic studies and DFT calculations of 4‐fluoro‐N‐(2‐hydroxy‐4‐nitrophenyl)benzamide
Authors: Ushakumari L. , Varghese Hema Tresa , Panicker C. Yohannan , Ertan Tugba , Yildiz Ilkay
Published: July 2008

Fourier transform infrared (FT‐IR) and FT‐Raman spectra of 4‐fluoro‐N‐(2‐hydroxy‐4‐nitrophenyl)benzamide were recorded and analyzed. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red‐shift of the NH‐stretching wavenumber in the infrared (IR) spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The simultaneous IR and Raman activation of the CO‐stretching mode gives the charge transfer interaction through a π‐conjugated path. Copyright © 2008 John Wiley & Sons, Ltd.
Resonance Raman study of He+ ion implanted nanostructured ZnS
Authors: Kumar S. Saravana , Khadar M. Abdul , Nair K. G. M. , Dhara S. , Magudapathy P.
Published: July 2008

ZnS nanocrytsals of size ∼2.5 nm were prepared by chemical precipitation technique. Pressed pellets of nanostructured ZnS were implanted with He+ ions at doses of 5 × 1014, 1 × 1015 and 5 × 1015 ions/cm2. Raman spectra of both unimplanted and He+ ion implanted samples were recorded with ultraviolet (UV) excitation. LO, 2LO, 2TO, (LO + TA) and (2TO − TA) modes of ZnS were observed in the resonance Raman spectra of the unimplanted nanostructured ZnS samples. In addition, a surface mode was observed at 294 cm−1. With the implantation of He+ ions, the 2TO mode disappeared and 2LO mode became prominent and this observation was attributed to the decrease in band gap of ZnS nanocrytsals due to ion implantation. The exciton–LO phonon coupling strength was determined from the intensity ratio of 2LO to LO modes and it was observed that the exciton–LO phonon coupling strength increases with increase in implantation dose. In the present work, we report for the first time the observation of 2TO mode in the resonance Raman spectrum of nanostructured ZnS and also the modification of exciton–LO phonon coupling strength of semiconductor nanoparticles by ion implantation. Copyright © 2008 John Wiley & Sons, Ltd.
Pseudopolymorphic transitions of niclosamide monitored by Raman spectroscopy
Authors: Sardo Mariana , Amado Ana M. , Ribeiro‐Claro Paulo J. A.
Published: July 2008

Niclosamide suffers pseudopolymorphic transformations when exposed to different ambient conditions, which can lead to changes in its bioavailability. In this study, the kinetics of the pseudopolymorphic transitions of niclosamide crystals are characterized. FT‐Raman spectroscopy is used to quantify the anhydrate and hydrate forms of niclosamide crystals, mostly because of its high sensitivity to the strong intermolecular interactions present in these systems. The samples are exposed to well‐characterized relative humidity (RH) conditions during different periods of time and both water diffusion and polymorphic changes are monitored from the corresponding changes observed in the vibrational spectra. Both hydration and dehydration were found to be single‐step processes, with a half‐life time of ca. 142 and 63 h, respectively, at 24 °C. Copyright © 2008 John Wiley & Sons, Ltd.
Selection of best candidates for multiorgan resection among patients with T4 gastric carcinoma
Authors: Oñate‐Ocaña Luis F. , Becker Mauricio , Carrillo José F. , Aiello‐Crocifoglio Vincenzo , Gallardo‐Rincón Dolores , Brom‐Valladares Rocío , Herrera‐Goepfert Roberto , Ochoa‐Carrillo Francisco , Beltrán‐Ortega Arturo
Published: July 2008

Background and Objective

Indications for gastrectomy in T4 gastric carcinoma (GC) remain controversial. Our aim was to define prognostic factors to select those patients with best chance to benefit from multiorgan resection.

Materials and Methods

A cohort of patients with T4 GC treated in a 19‐year period. Surgical morbidity‐associated factors were identified by logistic regression analysis. Prognostic factors were defined by Kaplan–Meier and Cox methods.

Results

Seven hundred eighteen patients were included (gastrectomy performed in 169). Surgical morbidity and mortality were 39% and 10.7%, respectively. Surgical morbidity were associated to extent of gastrectomy, age, serum albumin, and lymphocyte count (P = 0.0001). Presence of metastasis (hazard ratio [HR], 1.68; 95% confidence interval [95% CI], 1.19–2.36), albumin <3 g/dl plus lymphocytes <1,000 cells/mm3 (HR, 2.9; 95% CI, 1.8–4.6), presence of ascites (HR, 2.1; 95% CI, 1.06–4.2), age ≥50 (HR, 1.37; 95% CI, 1.02–1.8), and unresectable disease (HR, 2.6; 95% CI, 1.7–4.1) defined poor survival (P = 0.00001).

Conclusion

Performing a multiorgan resection must be balanced between chances for long‐term survival and surviving a potentially fatal operation. Absence of metastases, serum albumin levels >3 g/dl, and accomplishment of R0 resection select patients with high probability of benefit from multiorgan resection. J. Surg. Oncol. 2008;98:336–342. © 2008 Wiley‐Liss, Inc.
Linear and nonlinear stability thresholds for a diffusive model of pioneer and climax species interaction
Authors: Buonomo Bruno , Rionero Salvatore
Published: July 2008

In this paper a reaction–diffusion model describing two interacting pioneer and climax species is considered. The role of diffusivity and forcing (stocking or harvesting of the species) on the nonlinear stability of a coexistence equilibrium is analysed. The study is performed in the context of a new approach to nonlinear L2‐stability based on the analysis of stability of the zero solution of a suitable linear system of ordinary differential equations. Theorems concerning the effect of forcing and diffusivity on the dynamics are established and stability–instability thresholds for the system are obtained. An example to illustrate the practical use of the results is also provided. Copyright © 2008 John Wiley & Sons, Ltd.
Urinary excretion of strawberry anthocyanins is dose dependent for physiological oral doses of fresh fruit
Authors: Hollands Wendy , Brett Gary M. , Dainty Jack R. , Teucher Birgit , Kroon Paul A.
Published: July 2008

There is considerable interest in coloured fruits and berries as sources of biologically active anthocyanins. To examine the relationship between the oral dose and the amount excreted for anthocyanins from a food source across a physiological range of doses, volunteers were fed, in random order, four portions (100–400 g) of fresh strawberries as part of a standard breakfast. Urine was collected at 2 h intervals up to 8 h, and for the period 8–24 h. Fresh strawberries contained pelargonidin‐3‐glucoside as the major anthocyanin with smaller amounts of cyanidin‐3‐glucoside and pelargonidin‐3‐rutinoside. Anthocyanins were detected in the urine of all volunteers for all doses, predominantly as pelargonidin glucuronide and sulphate metabolites. There was a strong, linear relationship between oral dose and anthocyanin excretion (Pearson's product moment correlation coefficient = 0.692, p < 0.001, n = 40) which indicated that on an average, every additional unit of dose caused 0.0166 units of excretion. Within individuals, dose – excretion data fitted a linear regression model (median R2 = 0.93). We conclude that strawberry anthocyanins are partially bioavailable in humans with a linear relationship between oral dose and urinary excretion for doses up to 400 g fresh fruit.
Absorption of N‐phenylpropenoyl‐L‐amino acids in healthy humans by oral administration of cocoa (Theobroma cacao)
Authors: Stark Timo , Lang Roman , Keller Daniela , Hensel Andreas , Hofmann Thomas
Published: July 2008

Besides flavan‐3‐ols, a family of N‐phenylpropenoyl‐L‐amino acids (NPAs) has been recently identified as polyphenol/amino acid conjugates in the seeds of Theobroma cacao as well as in a variety of herbal drugs. Stimulated by reports on their biological activity, the purpose of this study was to investigate if these amides are absorbed by healthy volunteers after administration of a cocoa drink. For the first time, 12 NPAs were quantified in human urine by means of a stable isotope dilution analysis with LC‐MS/MS (MRM) detection. A maximum amount was found in the urine taken 2 h after the cocoa consumption. The highest absolute amount of NPAs excreted with the urine was found for N‐[4′‐hydroxy‐(E)‐cinnamoyl]‐L‐aspartic acid (5), but the highest recovery rate (57.3 and 22.8%), that means the percentage amount of ingested amides excreted with the urine, were determined for N‐[4′‐hydroxy‐(E)‐cinnamoyl]‐L‐glutamic acid (6) and N‐[4′‐hydroxy‐3′‐methoxy‐(E)‐cinnamoyl]‐L‐tyrosine (13). In order to gain first insights into the NPA metabolism in vivo, urine samples were analyzed by LC‐MS/MS before and after β‐glucuronidase/sulfatase treatment. As independent of the enzyme treatment the same NPA amounts were found in urine, there is strong evidence that these amides are metabolized neither via their O‐glucuronides nor their O‐sulfates. In order to screen for caffeic acid O‐glucuronides as potential NPA metabolites, urine samples were screened by means of LC‐MS/MS for caffeic acid 3‐O‐β‐D‐glucuronide and 4‐O‐β‐D‐glucuronide. But not even trace amounts of one of these glucuronides were detectable, thus excluding them as major NPA metabolites and underlining the importance of future investigations on a potential O‐methylation or reduction of the N‐phenylpropenoyl moiety in NPAs.
Fungal siderophores function as protective agents of LDL oxidation and are promising anti‐atherosclerotic metabolites in functional food
Authors: Pócsi István , Jeney Viktória , Kertai Pál , Pócsi Imre , Emri Tamás , Gyémánt Gyöngyi , Fésüs László , Balla József , Balla György
Published: July 2008

Iron‐mediated oxidation of low‐density lipoprotein has been implicated in the pathogenesis of vascular disorders such as atherosclerosis. The present investigations were performed to test whether hydrophobic fungal siderophores – hexadentate trihydroxamates desferricoprogen, desferrichrome, desferrirubin, and desferrichrysin – might suppress heme‐catalyzed LDL oxidation and the toxic effects of heme‐treated LDL on vascular endothelium. Indeed, two of these – desferricoprogen and desferrichrome – markedly increased the resistance of LDL to heme‐catalyzed oxidation. In similar dose–response fashion, these siderophores also inhibited the generation of LDL products cytotoxic to human vascular endothelium. When iron‐free fungal siderophores were added to LDL/heme oxidation reactions, the product failed to induce heme oxygenase‐1, a surrogate marker for the noncytocidal effects of oxidized LDL (not in the case of desferrichrysin). Desferricoprogen also hindered the iron‐mediated peroxidation of lipids from human atherosclerotic soft plaques in vitro, and was taken up in the gastrointestinal tract of rat. The absorbed siderophore was accumulated in the liver and was secreted in its iron‐complexed form in the feces and urine. The consumption of mold‐ripened food products such as aged cheeses and the introduction of functional foods and food additives rich in fungal iron chelators in diets may lower the risk of cardiovascular diseases.
Expression of microRNA processing machinery genes in rhesus monkey oocytes and embryos of different developmental potentials
Authors: Mtango Namdori R. , Potireddy Santhi , Latham Keith E.
Published: July 2008

MicroRNAs (miRNAs) are a class of small RNAs that silence gene expression. In animal cells, miRNAs bind to the 3′ untranslated regions of specific mRNAs and inhibit their translation. The correct regulation of mRNA expression by miRNAs is believed to be important for oocyte maturation, early development and implantation. We examined the expression of 25 mRNAs involved in the microRNA processing pathway in a nonhuman primate oocyte and embryo model. We observed that mRNAs related to miRNA splicing are downregulated during oocyte maturation while those related to miRNA processing are upregulated, indicating that there may exist a temporal difference in their activities related to transcriptional activity in germinal vesicle stage oocytes. We also observed that the vast majority of mRNAs examined were insensitive to α‐amanitin at the 8–16 cell stage. The expression data did not reveal a major impact of embryo culture, and hormonal stimulation protocol affected only a small number of mRNAs, suggesting that the components of the pathway may be accumulated in the oocyte during oogenesis and resistant to exogenous insults. In comparison to published mouse array data, we observed species differences and similarities in the temporal expression patterns of some genes, suggesting that miRNA processing may be regulated differently. These data extend our understanding of the potential roles of miRNA during primate embryogenesis. Mol. Reprod. Dev. 76: 255–269, 2009. © 2008 Wiley‐Liss, Inc.
Network design for time‐constrained delivery
Authors: Chen Hui , Campbell Ann Melissa , Thomas Barrett W.
Published: July 2008

To meet customer demand, delivery companies are offering an increasing number of time‐definite services. In this article, we examine the strategic design of delivery networks which can efficiently provide these services. Because of the high cost of direct connections, we focus on tree‐structured networks. As it may not be possible to identify a tree‐structured network that satisfies all of the delivery guarantees, we allow these guarantees to be violated but seek to minimize the sum of the violations. We establish the complexity of the problem and exploit an empirically identified solution structure to create new neighborhoods which improve solution values over more general neighborhood structures. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Collaborative procurement among competing buyers
Authors: Keskinocak Pinar , Savaşaneril Seçil
Published: July 2008

Collaborative procurement emerged as one of the many initiatives for achieving improved inter‐firm coordination and collaboration. In this article, we adopt a game‐theoretical approach to study the interaction between two firms who procure jointly, but produce independently and remain competitors in a product market characterized by price‐sensitive demand. We study the underlying economics behind collaborative procurement, examine the effects of collaboration on buyer and supplier profitability, and derive conditions under which collaboration is beneficial to each participant. We find that a necessary and sufficient condition for a buyer to collaborate is to increase its sales. We identify the conditions that lead equal size buyers (i.e., consortia consisting of only large buyers or only small buyers) versus different size buyers to collaborate. We also determine the conditions that make collaboration profitable for the supplier, and show that rather than selling a large quantity to a single buyer, the supplier prefers to sell to multiple buyers in smaller quantities. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Collection depots facility location problems in trees
Authors: Benkoczi Robert , Bhattacharya Binay , Tamir Arie
Published: July 2008

We consider a generalization of the median and center facility location problem called the collection depots facility location (CDFL) problem. We are given a set of client locations and a set of collection depots and we are required to find the placement for a certain number of facilities, so that the cost of dispatching a vehicle from a facility, to a client, to a collection depot, and back, is optimized for all clients. The CDFL center problem minimizes the cost of the most expensive vehicle tour among all clients, and the CDFL median problem minimizes the sum of the tour costs for all clients. We provide the first polynomial time algorithms to solve the 1 and k median problems in trees with time complexities O(n log n) and O(kn3), respectively, where n is the number of vertices in the tree. In contrast, a restricted version of the k‐median problem, where clients are given lists of allowed collection depots, is NP‐complete even for star graphs. We also give an optimal linear time algorithm to solve the discrete and continuous weighted 1‐center problem, improving on the O(n log n) result of Tamir and Halman [Discrete Optimization 2(2005), 168–184]. © 2008 Wiley Periodicals, Inc. NETWORKS, 2009
Conceptualizing and measuring illness self‐concept: A comparison with self‐esteem and optimism in predicting fibromyalgia adjustment
Authors: Morea Jessica M. , Friend Ronald , Bennett Robert M.
Published: July 2008

Illness self‐concept (ISC), or the extent to which individuals are consumed by their illness, was theoretically described and evaluated with the Illness Self‐Concept Scale (ISCS), a new 23‐item scale, to predict adjustment in fibromyalgia. To establish convergent and discriminant validity, illness self‐concept was compared to self‐esteem and optimism in predicting health status, illness intrusiveness, depression, and life satisfaction. The ISCS demonstrated good reliability (α = .94; test–retest r = .80) and was a strong predictor of outcomes, even after controlling for optimism or self‐esteem. The ISCS predicted unique variance in health‐related outcomes; optimism and self‐esteem did not, providing construct validation. Illness self‐concept may play a significant role in coping with fibromyalgia and may prove useful in the evaluation of other chronic illnesses. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:563–575, 2008
Thiophene‐based ionic liquids: synthesis, physical properties, self‐assembly, and oxidative polymerization
Authors: Burns Christopher T. , Lee Sungwon , Seifert Sönke , Firestone Millicent A.
Published: July 2008

Preparation and polymerization of methylimidazolium‐based ionic liquids (ILs) that incorporate a thiophene moiety at the terminus of a C10 alkyl chain are described. Both a bromide and nitrate salt of the amphiphilic thiophene IL self‐assembles in water (albeit the nitrate to a lesser extent), adopting columnar mesophases. Polarized optical microscopy and small‐angle X‐ray scattering (SAXS) studies show that at low water content the IL–water binary mixtures form liquid crystalline mesophases possessing significant short‐range ordering due to strong π interactions between adjacent thiophene moieties. At higher water content, the short‐range ordering is lost, but long‐range ordering persists up to ca. 45% (w/w) water. The chemical oxidative coupling of the nitrate monomer yields a highly water‐soluble polymer. Electrochemical studies show that the polymer possesses a high oxidation potential (1.95 V) and thus, is resistant to chemical doping. In dilute aqueous solution, electronic absorption spectroscopy and X‐ray scattering show the polymer adopts a random, coil‐like conformational state. Slight improvement in the polymer conformation can be achieved by exchange of the counter anion. Copyright © 2008 John Wiley & Sons, Ltd.