bluuebunny/crossref_metadata_2025 huggingface dataset:
Apathy following subthalamic stimulation in Parkinson disease: A dopamine responsive symptom
Authors: Czernecki Virginie , Schüpbach Michael , Yaici Sadek , Lévy Richard , Bardinet Eric , Yelnik Jérôme , Dubois Bruno , Agid Yves
Published: April 2008

To evaluate the effects of the dopamine D2‐D3 agonist ropinirole in patients who developed apathy after complete withdrawal from dopaminergic medication following successful subthalamic nucleus (STN) stimulation for advanced Parkinson disease (PD). We assessed apathy (Apathy Scale, Apathy Inventory), mood (Montgomery‐Åsberg Depression Rating Scale), cognitive functions (Mattis Dementia rating scale, frontal score, executive tests) and motor state (UPDRS‐III) in 8 PD patients treated with STN stimulation without dopaminergic treatment and who became apathetic. Assessments were made at baseline and after 6 weeks of ropinirole treatment (7.2 ± 5.9 mg/d; range 1–18 mg/d). Apathy improved with ropinirole in all but 1 patient (54 ± 24%; range 0–78%). Mood also improved (75 ± 31%; range 0–100%), but not in correlation with the change in apathy. Cognitive performance was not modified. Stimulation contacts were located within the STN in all patients except the one who remained apathetic in spite of ropinirole treatment (zona incerta). We suggest that apathy, which was compensated for by an enhancement of D2‐D3 receptor stimulation in PD patients with STN stimulation: (1) depends on a dopaminergic deficit in associativo‐limbic areas of the brain and (2) can be avoided if a dopaminergic agonist is administered postoperatively. © 2008 Movement Disorder Society
Effect of curcumin supplementation on blood glucose, plasma insulin, and glucose homeostasis related enzyme activities in diabetic db/db mice
Authors: Seo Kwon‐Il , Choi Myung‐Sook , Jung Un Ju , Kim Hye‐Jin , Yeo Jiyoung , Jeon Seon‐Min , Lee Mi‐Kyung
Published: April 2008

We investigated the effect of curcumin on insulin resistance and glucose homeostasis in male C57BL/KsJ‐db/db mice and their age‐matched lean non‐diabetic db/+ mice. Both db/+ and db/db mice were fed with or without curcumin (0.02%, wt/wt) for 6 wks. Curcumin significantly lowered blood glucose and HbA1c levels, and it suppressed body weight loss in db/db mice. Curcumin improved homeostasis model assessment of insulin resistance and glucose tolerance, and elevated the plasma insulin level in db/db mice. Hepatic glucokinase activity was significantly higher in the curcumin‐supplemented db/db group than in the db/db group, whereas glucose‐6‐phosphatase and phosphoenolpyruvate carboxykinase activities were significantly lower. In db/db mice, curcumin significantly lowered the hepatic activities of fatty acid synthase, β‐oxidation, 3‐hydroxy‐3‐methylglutaryl coenzyme reductase, and acyl‐CoA: cholesterol acyltransferase. Curcumin significantly lowered plasma free fatty acid, cholesterol, and triglyceride concentrations and increased the hepatic glycogen and skeletal muscle lipoprotein lipase in db/db mice. Curcumin normalized erythrocyte and hepatic antioxidant enzyme activities (superoxide dismutase, catalase, gluthathione peroxidase) in db/db mice that resulted in a significant reduction in lipid peroxidation. However, curcumin showed no effect on the blood glucose, plasma insulin, and glucose regulating enzyme activities in db/+ mice. These results suggest that curcumin seemed to be a potential glucose‐lowering agent and antioxidant in type 2 diabetic db/db mice, but had no affect in non‐diabetic db/+ mice.
Immunomodulatory effects of curcumin in allergy
Authors: Kurup Viswanath P. , Barrios Christy S.
Published: April 2008

Recent years have witnessed a global increase in allergy and asthma, particularly in developed countries. Attempts to develop effective control measures for allergy and asthma resulted in the exploration of alternate medicines including herbal remedies traditionally used in old world countries. Turmeric is known for its multiple health restoring properties, and has been used in treating several diseases including several respiratory disorders. Turmeric is a common spice used in the culinary preparations in South and East Asian countries. The active component of turmeric is curcumin, a polyphenolic phytochemical, with anti‐inflammatory, antiamyloid, antiseptic, antitumor, and antioxidative properties. Curcumin was reported to have antiallergic properties with inhibitory effect on histamine release from mast cells. The effectiveness of curcumin in allergy and asthma has been further investigated using a murine model of allergy. The results indicate a marked inhibition of allergic response in animals treated with curcumin suggesting a major role for curcumin in reducing the allergic response. The present review focuses on the results of research aimed to understand the immunomodulation induced by curcumin and its associated roles in the amelioration of allergy. These findings needed further evaluation, extrapolation, and confirmation before using curcumin for controlling allergy and asthma in humans.
Resveratrol inhibits migration and invasion of human breast‐cancer cells
Authors: Tang Feng‐Yao , Su Yu‐Ching , Chen Nai‐Chia , Hsieh Hui‐Shan , Chen Kaun‐Suei
Published: April 2008

Metastasis is the primary cause of death from breast cancer. Cell migration and invasion play important roles in neoplastic metastasis. The insulin‐like growth factor (IGF‐1) stimulates cell migration through activation of PI‐3K/Akt signaling pathway. IGF‐1 induces the tumorigenicity of many types of cancer cells and is critical for metastatic cell spread in estrogen receptor (ER)‐negative breast‐cancer cells. Matrix metalloproteinase‐2 (MMP‐2) is a key enzyme in the degradation of extracellular matrices and its expression has been dysregulated in breast cancer invasion and metastasis. Resveratrol exhibited potential anticarcinogenic activities in several studies. However, the inhibitory effects of resveratrol on the expression of MMP‐2, migration and invasion of breast‐cancer cell have not been demonstrated yet. In the present study, we investigated the anti‐invasive mechanism of resveratrol in human breast cancer MDA‐MB 435cells. Here, we showed that IGF‐1 is a potent stimulant of the migration of ER‐negative human breast‐cancer cells. Resveratrol could inhibit IGF‐1‐mediated cell migration of MDA‐MB 435 in vitro. The inhibitory effect of resveratrol was mediated in part through the suppression of the activation of PI‐3K/Akt signaling pathway. Furthermore, IGF‐1‐mediated expression of MMP‐2 was significantly inhibited by resveratrol in concomitance with alteration of cell invasion.
Structure elucidation of five new iridoid glucosides from the leaves of Avicennia marina
Authors: Sun Yu , Ouyang Jie , Deng Zhiwei , Li Qingshan , Lin Wenhan
Published: April 2008

A chemical examination of the mangrove plant Avicennia marina (Forrsk.) Vierh resulted in the isolation and characterization of five new iridoids, marinoids A–E (1–5), along with 2′‐cinnamoyl‐mussaenosidic acid (6), 2′‐O‐(4″‐methoxycinnamoyl) mussaenosidic acid (7), 2′‐O‐(4″‐hydroxycinnamoyl) mussaenosidic acid (8), and 3(R)‐hydroxy‐5‐phenyl‐4(E)‐pentenoic acid (9). The structures of 1–5 were elucidated on the basis of 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) in association with IR and MS data analysis. Copyright © 2008 John Wiley & Sons, Ltd.
Genomic origin, processing and developmental expression of testicular outer dense fiber 2 (ODF2) transcripts and a novel nucleolar localization of ODF2 protein
Authors: Rivkin Eugene , Tres Laura L. , Kierszenbaum Abraham L.
Published: April 2008

Outer dense fibers are a major constituent of the sperm tail and outer dense fiber 2 (ODF2) protein is one of their major components. ODF2 shares partial homology with cenexin 1 and cenexin 2, regarded as centriolar proteins. We show that ODF2 and cenexin 2 transcripts are the product of differential splicing of a single gene, designated Cenexin/ODF2 and that cenexin 1 is an incomplete clone of ODF2. ODF2 terminates in exon 20b whereas in cenexin 2 this exon is spliced out and translation terminates in exon 24. We demonstrate a transcriptional switch during rat testicular development, from somatic‐type to testis‐type ODF2 and cenexin transcripts during the onset of meiosis. The switch is completed when spermiogenesis is established. ODF2 immunoreactive sites were visualized in the acroplaxome, along the sperm tail and the centrosome‐derived sperm head‐to‐tail coupling apparatus. An unexpected finding was the presence of ODF2 antigenic sites, but not cenexin antigenic sites, in the dense fibrillar component of the nucleolus of Sertoli cells, spermatogonia and primary spermatocytes. The characterization of the genomic origin, processing and developmental expression of ODF2 transcript isoforms and their protein products can help reconcile differences in the literature on the role of ODF2 and cenexin in the centrosome. Furthermore, the finding of ODF2 in the dense fibrillar component of the nucleolus suggests that this protein, in addition to its presence in sperm outer dense fibers and centrosome, highlights and adds to the nucleolar function during spermatogenesis and early embryogenesis. Mol. Reprod. Dev. 75: 1591–1606, 2008. © 2008 Wiley‐Liss, Inc.
High order implicit collocation method for the solution of two‐dimensional linear hyperbolic equation
Authors: Dehghan Mehdi , Mohebbi Akbar
Published: April 2008

In this article, we introduce a high‐order accurate method for solving the two dimensional linear hyperbolic equation. We apply a compact finite difference approximation of fourth order for discretizing spatial derivatives of linear hyperbolic equation and collocation method for the time component. The resulted method is unconditionally stable and solves the two‐dimensional linear hyperbolic equation with high accuracy. In this technique, the solution is approximated by a polynomial at each grid point that its coefficients are determined by solving a linear system of equations. Numerical results show that the compact finite difference approximation of fourth order and collocation method give a very efficient approach for solving the two dimensional linear hyperbolic equation. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
A characteristic finite element method with local mesh refinements for the Lamm equation in analytical ultracentrifugation
Authors: Liu Jiangguo , Chen Chaoping
Published: April 2008

The Lamm equation is a fundamental differential equation in analytical ultracentrifugation, for describing the transport of solutes in an ultracentrifuge cell. In this article, we present a characteristic finite element method with local mesh refinements for solving the Lamm equation. The numerical method is mass‐conservative by design and allows relatively large time steps to be used. Numerical experiments indicate that the numerical solutions are oscillation‐free in the region near the cell bottom, where mass build up and large concentration gradients occur. Positivity of solutions is also well kept. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Prenatal testing for a novel EBP missense mutation causing X‐linked dominant chondrodysplasia punctata
Authors: Tysoe Carolyn , Law Caroline J. , Caswell Richard , Clayton Peter , Ellard Sian
Published: April 2008

Objective

To determine the pathogenicity of a novel conserved missense mutation, p.Ser98Phe, in the emopamil binding protein (EBP) gene in order to perform a prenatal diagnostic test for X‐linked dominant chondrodysplasia punctata (CDPX2) in a male foetus at 50% risk.

Methods

Family members were tested for p.Ser98Phe using PCR and sequence analysis of leucocyte or buccal cell DNA. Haplotype analysis was employed to identify the grandparental chromosome on which p.Ser98Phe had arisen. In silico protein analyses were used to predict whether p.Ser98Phe significantly altered the EBP protein structure.

Results

The mutation was detected in the proband and her affected mother but not in the maternal grandmother, who was thought to be mildly affected. However, haplotype analysis showed that p.Ser98Phe had arisen de novo on the grandpaternal X chromosome. Protein secondary structure predictions suggested that p.Ser98Phe alters the properties of the helix within which it is located.

Conclusion

We concluded that p.Ser98Phe is likely to be pathogenic and proceeded with prenatal testing. The male foetus had not inherited p.Ser98Phe and his unaffected status was confirmed at birth. This family demonstrates some of the difficulties in interpreting the significance of novel missense mutations, particularly when results are needed urgently for prenatal diagnosis. Copyright © 2008 John Wiley & Sons, Ltd.
Inhibin A measurement using an automated assay platform
Authors: Lambert‐Messerlian G. M. , Palomaki G. E. , Canick J. A.
Published: April 2008

Background

Second–trimester measurement of maternal serum inhibin A is widely used for Down syndrome screening. To date, only a manual enzyme‐linked immunosorbent assay (ELISA) produced by Diagnostic Systems Laboratories, Inc (DSL) has been available. The objective of this study was to compare the DSL assay with a new automated assay produced by Beckman Coulter, Inc (Access).

Methods

Residual serum samples from 570 women, who were receiving routine screening for Down syndrome, were retrieved from storage. The Access assay sensitivity, linearity and reproducibility were determined and a method comparison was performed. Inhibin A levels were measured using both assays. Twenty samples from women with confirmed Down syndrome pregnancy were also tested.

Results

The Access assay had coefficients of variation of less than 10% across the range of values tested, and a sensitivity below 1 pg/mL. The DSL and Access inhibin A assay values were highly correlated (r = 0.961, r2 = 0.923), with no apparent outliers. Inhibin A values from the Access assay were a constant 23% lower (95% CI 1–41%) than corresponding values from the DSL assay. Median values from 15 to 20 completed weeks' gestation were computed and found to be consistent with expectations. The weight‐adjusted multiples of the median (MoM) levels in the unaffected pregnancies fit a log Gaussian distribution well between at least the 5th and 95th percentiles with corresponding log standard deviations of 0.1960 and 0.1919 for DSL and Access, respectively.

Conclusions

With median inhibin A levels appropriately calculated for the Access assay, Down syndrome screening performance is expected to be comparable to that obtained with the manual DSL assay. Copyright © 2008 John Wiley & Sons, Ltd.
Refined fluorescent STR quantification of cell‐free fetal DNA during pregnancy in physiological and Down syndrome fetuses
Authors: Vodicka Radek , Vrtel Radek , Dusek Ladislav , Prochazka Martin , Schneiderova Eva , Vrbicka Dita , Krejcirikova Eva , Dhaifalah Ishraq , Santava Alena , Santavy Jiri
Published: April 2008

Background

Cell‐free fetal (cff) DNA analysis by short tandem repeats (STR) has the advantage of better recognizing the different genotypes. However, quantitative examination by quantitative fluorescent (QF) polymerase chain reaction (PCR) by STRs is limited to only a rough approximation. This project focuses on a more precise calculation of the relative cff DNA amount tested in the STRs' loci.

Methods

The cff DNA was analyzed in 363 samples from 258 pregnant women with physiological fetuses in different stages of pregnancy (from 4–37 gestational weeks) separately in three STRs [D21S1435, D21S1446 and PentaD (pD)] and also by gonosomal sequences amelogenin gene, X/Y‐linked/testis specific protein, Y‐linked (AMELX/Y/TSPY). Seventeen samples of cff DNA from fetuses with Down syndrome (DS) were compared. We optimized the refined quantitative fluorescent (RQF) PCR for STRs in a particular locus.

Results and Conclusions

The cff DNA detection rate was 74% in at least one of the STRs. The efficiency decreased from shorter to longer PCR fragments. All three STR and gonosomal loci proved an increase in cff DNA during pregnancy. The stutter variability rate is greatest in short STR fragments and decreases as the STR fragments increase in length. Results showed that DS samples had a significantly higher amount of cff DNA. Copyright © 2008 John Wiley & Sons, Ltd.
What is reinforcement sensitivity? Neuroscience paradigms for approach‐avoidance process theories of personality
Authors: Smillie Luke D.
Published: April 2008

Reinforcement sensitivity is a concept proposed by Gray (1973) to describe the biological antecedents of personality, and has become the common mechanism among a family of personality theories concerning approach and avoidance processes. These theories suggest that 2–3 biobehavioural systems mediate the effects of reward and punishment on emotion and motivation, and that individual differences in the functioning of these systems manifest as personality. Identifying paradigms for operationalising reinforcement sensitivity is therefore critical for testing and developing these theories, and evaluating their footprint in personality space. In this paper I suggest that, while traditional self‐report paradigms in personality psychology may be less‐than‐ideal for this purpose, neuroscience paradigms may offer operations of reinforcement sensitivity at multiple levels of approach and avoidance processes. After brief reflection on the use of such methods in animal models—which first spawned the concept of reinforcement sensitivity—recent developments in four domains of neuroscience are reviewed. These are psychogenomics, psychopharmacology, neuroimaging and category‐learning. By exploring these paradigms as potential operations of reinforcement sensitivity we may enrich our understanding of the putative biobehavioural bases of personality. Copyright © 2008 John Wiley & Sons, Ltd.
Living up to high standards and psychological distress
Authors: Van Yperen Nico W. , Hagedoorn Mariët
Published: April 2008

We argue and demonstrate that setting high standards, an essential aspect of perfectionism, is not associated with maladaptive responses in and of itself. Rather, our findings suggest that people's responses to their perceptions that they consistently fail to meet their own standards are maladaptive. More importantly, in the present survey study (n = 293), we extend previous research by showing that low personal standards and the perception that others are imposing high standards on the self operate in concert to strengthen the link between perceived discrepancy and psychological distress. Furthermore, in support of our moderation‐mediation model, regression analyses provided evidence for the mediating role of generalised self‐efficacy beliefs. Copyright © 2008 John Wiley & Sons, Ltd.
Staining efficiency of specific proteins depends on the staining method: Wheat gluten proteins
Authors: van den Broeck Hetty C. , America Antoine H. P. , Smulders Marinus J. M. , Gilissen Ludovicus J. W. J. , van der Meer Ingrid M.
Published: April 2008

To analyze gluten proteins involved in celiac disease (CD) by proteomic analysis, prolamins extracted from hexaploid wheat varieties were analyzed by SDS‐PAGE and 2‐DE. Differences between staining methods (CBB, silver nitrate, SYPRO Ruby, and CyDye) were analyzed in comparison to immunoblotting. Staining efficiency varied per protein across methods, and complete staining of all gluten proteins could not be achieved by one of these methods. Care should be taken in the selection of staining method especially if one wants to relate the results to data obtained by immunoblotting.
Post‐translational modification of cellular proteins during Leishmania donovani differentiation
Authors: Rosenzweig Doron , Smith Derek , Myler Peter J. , Olafson Robert W. , Zilberstein Dan
Published: April 2008

The pathogenic intracellular parasites Leishmania donovani cycle between sand fly gut and the human macrophage phagolysosome, differentiating from extracellular promastigotes to intracellular amastigote forms. Using isobaric tagging for relative and absolute quantifications (iTRAQ/LC‐MS/MS) proteomic methodology, we recently described the ordered gene expression changes during this process. While protein abundance changes in Leishmania were documented, little is known about their PTMs. Here we used iTRAQ to detect protein phosphorylation, methylation, acetylation, and glycosylation sites throughout differentiation. We found methylation of arginines, aspartic acids, glutamic acids, asparagines, and histidines. Detected acetylation sites included serines and protein N‐terminal acetylations on methionines, serines, alanines, and threonines. Phosphorylations were detected on serines and threonines, but not tyrosines. iTRAQ identified novel fucosylation sites as well as hexosylations. We observed quantity changes in some modifications during differentiation, suggesting a role in L. donovani intracellular development. This study is the first high‐throughput analysis of PTM sites dynamics during an intracellular parasitic development.
Thermodynamics of dark energy
Authors: Bilić N.
Published: April 2008

Thermodynamic properties of dark energy are discussed assuming that dark energy is described in terms of a selfinteracting complex scalar. We first show that, under certain assumptions, selfinteracting complex scalar field theories are equivalent to purely kinetic k‐essence models. Then we analazie the themal properties of k‐essence and in particular we show that dark‐energy in the phantom regime does not necesserely yield negative entropy.
Coset space dimensional reduction of Einstein–Yang–Mills theory
Authors: Chatzistavrakidis A. , Manousselis P. , Prezas N. , Zoupanos G.
Published: April 2008

In the present contribution we extend our previous work by considering the coset space dimensional reduction of higher‐dimensional Einstein–Yang–Mills theories including scalar fluctuations as well as Kaluza–Klein excitations of the compactification metric and we describe the gravity‐modified rules for the reduction of non‐abelian gauge theories.
Non‐topological non‐commutativity in string theory
Authors: Guttenberg S. , Herbst M. , Kreuzer M. , Rashkov R.
Published: April 2008

Quantization of coordinates leads to the non‐commutative product of deformation quantization, but is also at the roots of string theory, for which space‐time coordinates become the dynamical fields of a two‐dimensional conformal quantum field theory. Appositely, open string diagrams provided the inspiration for Kontsevich's solution of the long‐standing problem of quantization of Poisson geometry by virtue of his formality theorem. In the context of D‐brane physics non‐commutativity is not limited, however, to the topolocial sector. We show that non‐commutative effective actions still make sense when associativity is lost and establish a generalized Connes‐Flato‐Sternheimer condition through second order in a derivative expansion. The measure in general curved backgrounds is naturally provided by the Born–Infeld action and reduces to the symplectic measure in the topological limit, but remains non‐singular even for degenerate Poisson structures. Analogous superspace deformations by RR–fields are also discussed.
Observational effects of strong gravity in vicinity of supermassive black holes
Authors: Jovanović P. , Popović L.Č.
Published: April 2008

Here we discuss the effects of strong gravity that can be observed in electromagnetic spectra of active galactic nuclei (AGN). According to the unification model of an AGN, there is a supermassive black hole (107 ‐ 109 MȮ) in its center, surrounded by an accretion disk that radiates in the X‐ray band. Accretion disks could have different forms, dimensions, and emission, depending on the type of central black hole (BH), whether it is rotating (Kerr metric) or nonrotating (Schwarzschild metric). We modeled the emission of an accretion disk around supermassive BH using numerical simulations based on a ray‐tracing method in the Kerr metric. A broad emission line Fe Kα at 6.4 keV with asymmetric profile (narrow bright blue peak and a wide faint red wing) has been observed in a number of type 1 AGN. The effects of strong gravitational field are investigated by comparison between the modeled and observed iron Kα line profiles. The results of our modeling show that the parameters of the Fe Kα line emitting region have significant influence on the line profile and thus, allow us to determine the space‐time geometry (metric) in vicinity of the central BH of AGN, and also can give us information about the plasma conditions in these regions.
Masses of tetraquark candidates D
Authors: Borka Jovanović V.
Published: April 2008

Using the Glozman‐Riska (flavor‐spin) interaction Hamiltonian and the SU(3) flavor symmetry breaking, we perform a schematic study of the masses of the scalar charmed tetraquarks in the following representations: $\overline{15}_\mathrm{S}$, $\bar{3}_\mathrm{S}$, $6_\mathrm{A}$ and$\bar{3}_\mathrm{A}$. Obtained pattern indicates that Ds+(2317) is a four‐quark state in the SU(3)F $\bar{3}_\mathrm{A}$ representation. Ds+(2632) is identified with a state from mixing of the $\overline{15}_\mathrm{S}$ and $\bar{3}_\mathrm{S}$ representations. There are 27 different tetraquarks composed of a charm quark c and of the three light flavors u, d, s: 11 cryptoexotic (3 Ds+, 4 D+, 4 D0) and 16 explicit exotic states. The identification of Ds+(2317) and Ds+(2632) with two cryptoexotic states in tetraquark spectrum is possible when including Glozman‐Riska hyperfine interaction. We also compare Glozman‐Riska and Fermi‐Breit contributions to the tetraquark masses and analyze the corresponding tetaraquark mass spectra.
Giant magnons on γ deformed AdS5 × S5
Authors: Rashkov R.C. , Stoilov N.M.
Published: April 2008

In this short note we report on the dispersion relation of a new magnon type string solution in γ deformed AdS5 × S5 background. Our magnon solution has one spin in AdS5 part and two in S5 part of the background.
R4 in type II superstrings
Authors: Tsimpis D.
Published: April 2008

We review the result, given in [1], of the complete four‐point effective action of both type II superstrings to all orders in α′, at tree level in string loops. We find that, in the quartic‐field approximation, the supergravity Lagrangian can be thought of as the tensor product of two copies of the super Yang‐Mills Lagrangian in ten dimensions.
Interaction of the particle with the string in pole‐dipole approximation
Authors: Vasilić M. , Vojinović M.
Published: April 2008

Within the framework of generalized Papapetrou method, we derive the effective equations of motion for a string with two particles attached to its ends, along with appropriate boundary conditions. The equations of motion are the usual Nambu‐Goto‐like equations, while boundary conditions turn out to be equations of motion for the particles at the string ends. The form of those equations is discussed, and they are explicitly solved for a particular case of a straight‐line string rotating around its center. From this solution we obtain the correction terms to the J ∝ E2 law describing Regge trajectories, due to nonzero angular momenta of the particles.
Perturbative quantum corrections and flux compactifications
Authors: Berg M. , Haack M. , Pajer E.
Published: April 2008

We review the results of arxiv:0704.0730, a string theory test of the phenomenologically interesting large volume scenario (LVS) of Balasubramanian et al. In particular, we consider whether the LVS expansion of the string effective action is consistent when the open string one‐loop corrections due to D‐branes and O‐planes are taken into account. The result is that LVS is surprisingly robust. We also review the computation of soft supersymmetry breaking terms, which is only modified at subleading order.
Expression profiling of CD133+ and CD133— epithelial cells from human prostate
Authors: Shepherd Christopher J. , Rizzo Siân , Ledaki Ioanna , Davies Melissa , Brewer Daniel , Attard Gerhardt , de Bono Johann , Hudson David L.
Published: April 2008

BACKGROUND

Recent evidence suggests that prostate stem cells in benign and tumor tissue express the cell surface marker CD133, but these cells have not been well characterized. The aim of our study was to gene expression profile CD133‐expressing cells.

METHODS

We analyzed CD133‐positive (CD133+) and ‐negative (CD133−) sub‐populations of high‐integrin expressing epithelial cells isolated from benign human prostate tissue and hormone‐refractory prostate cancer (HRPC).

RESULTS

CD133+ cells freshly isolated from benign prostate tissue exhibited an expression profile characteristic of a putative stem/progenitor cell population, with transcripts involved in biological processes ranging from development and ion homeostasis to cell communication. The profile of CD133− cells was consistent with that of a transit amplifying population, suggesting up‐regulated proliferation and metabolism. Comparison of benign populations to those from HRPC showed some similarities between CD133+ profiles but also revealed significant differences that provide a tumor‐specific pattern, which included evidence of increased metabolic activity and active proliferation. Subsequently, we demonstrated protein expression of a number of candidate genes in these cell populations and in benign tissue. In a novel observation we also found expression of some of these markers in prostate tumors, including the oligodendrocyte lineage transcription factor OLIG1.

CONCLUSIONS

This study provides a unique genome‐wide molecular signature of CD133+ and CD133− human prostate epithelial cells. This will provide a valuable resource for prostate stem cell biology research and the identification of novel therapeutic targets for the treatment of prostate cancer. Prostate 68:1007–1024, 2008. © 2008 Wiley‐Liss, Inc.
Analysis of the sequence and structural features of the left‐handed β‐helical fold
Authors: Choi Jay H. , Govaerts Cedric , May Barnaby C. H. , Cohen Fred E.
Published: April 2008

The left‐handed parallel β‐helix (LβH) is a structurally repetitive, highly regular, and symmetrical fold formed by coiling of elongated β‐sheets into helical “rungs.” This canonical fold has recently received interest as a possible solution to the fibril structure of amyloid and as a building block of self‐assembled nanotubular structures. In light of this interest, we aimed to understand the structural requirements of the LβH fold. We first sought to determine the sequence characteristics of the repeats by analyzing known structures to identify positional preferences of specific residues types. We then used molecular dynamics simulations to demonstrate the stabilizing effect of successive rungs and the hydrophobic core of the LβH. We show that a two‐rung structure is the minimally stable LβH structure. In addition, we defined the structure‐based sequence preference of the LβH and undertook a genome‐wide sequence search to determine the prevalence of this unique protein fold. This profile‐based LβH search algorithm predicted a large fraction of LβH proteins from microbial origins. However, the relative number of predicted LβH proteins per specie was approximately equal across the genomes from prokaryotes to eukaryotes. Proteins 2008. © 2008 Wiley‐Liss, Inc.
A monitoring programme for 1,3‐dichloropropene and metabolites in groundwater in five EU countries
Authors: Terry Adrian S , Carter Andrée D , Humphrey Rebecca L , Capri Ettore , Grua Bruno , Panagopoulous Andreas C , Pulido‐Bosch Antonio , Kennedy Stephen H
Published: April 2008

BACKGROUND: 1,3 Dichloropropene (1,3‐D) is a preplanting soil fumigant for the control of cyst and free‐living nematodes and is currently undergoing a resubmission under Annex 1 listing of Directive 91/414/EEC. The characteristics of 1,3‐D are such that the risk of it or its soil metabolites leaching through the soil profile cannot be excluded. As such, groundwater monitoring programmes were established in five EU countries representing a wide range of agricultural, climatic and hydrogeological situations, covering a range of groundwater vulnerability scenarios. All monitoring was conducted in areas where there has been historical use of 1,3‐D.

RESULTS: Over 5000 groundwater samples were analysed for the presence of 1,3‐D and its metabolites over a 2 year period. Almost all analyses (for parent and metabolites) yielded concentrations of < 0.1 µg L−1. There were just two detections of > 0.1 µg L−1 (0.12 µg L−1 and 0.4 µg L−1) for the 3‐chloroacrylic acid metabolite in shallow groundwater samples of the alluvial gravels of the River Tiétar in the Caceres region of Spain.

CONCLUSION: Groundwater monitoring programmes have been conducted in the EU in five countries. These have demonstrated that there is negligible contamination of groundwater with 1,3‐D or its metabolites across a range of agroclimatic regions where 1,3‐D is known to have been used for a number of years. Local scientific knowledge of geological features, hydrology, agricultural practice and specific local issues was essential to the conduct of the study. Copyright © 2008 Society of Chemical Industry
Controlling charge‐transfer at the gate interface of organic field‐effect transistors
Authors: Mühlenen Adrian von , Castellani Mauro , Schaer Michel , Zuppiroli Libero
Published: April 2008

The performance and charge transport characteristics of pentacene transistors with oxide gates such as SiO2 and Al2O3 have been recently shown to largely depend on the density of residual carriers due to electron acceptor defects at the oxide surface. The threshold field in particular is strongly connected to the density of these surface states. We demonstrate that by vapor deposition of self‐assembled monolayers on the oxide gate prior to pentacene growth this charge transfer process is inhibited, the residual charge concentration is decreased by up to two orders of magnitude, and the field‐effect mobility increases by up to a factor of four. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exponential series representation for heat capacities of semiconductors and wide‐bandgap materials
Authors: Pässler Roland
Published: April 2008

The Thirring series expansion is used as the starting point for the design of a structurally novel, dispersion‐related analytical model for descriptions of the temperature dependences of harmonic parts of isochoric heat capacities, CVh (T). The notorious problem of slow convergence of this conventional series expansion is satisfactorily resolved here by its transformation into an associated exponential series representation, which shows up markedly better convergence properties than the original Thirring expansion. Combining this unprecedented analytical CVh (T) model in a physically adequate way with the recently introduced power series expansion for contributions of lattice expansion and anharmonicity effects to the observable isobaric heat capacities, we get a novel effective tool for numerical simulations and analyses of corresponding Cp (T) data sets, which is suitable for applications to the practically important regions of intermediate to high temperatures. This model is usable, among other things, as a physically consistent substitution for various types of ad hoc chosen polynomials that are hitherto still frequently used, especially in the field of thermochemistry. In order to illustrate the considerable usefulness of the novel analytical tool, especially for the technologically important class of wide‐bandgap materials, we perform simultaneous least‐mean‐square fittings of combined sets of available high‐ and low‐temperature Cp (T) data for diamond, SiC‐3C, the III‐nitrides BN, AlN, and GaN, and the zinc chalcogenides ZnO, ZnS, and ZnSe. For a comparison with results obtained recently for Si and Ge on the basis of a three‐oscillator model, we have re‐examined the respective Cp (T) data sets. As interesting byproducts of present fittings we evaluate several even‐order moments of the respective phonon density of states spectral functions. The discussion of numerical results reveals, among other things, the basic physical cause of the obvious inappropriateness of the conventional Debye model with respect to the majority of the materials under study. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical studies of the spin Hamiltonian parameters and the local structure for the orthorhombic V4+ in CaYAlO4
Authors: Fu Chuan‐Ji , Wu Shao‐Yi , Wei Li‐Hua , Zhang Zhi‐Hong , Hu Yue‐Xia
Published: April 2008

The spin Hamiltonian parameters (g ‐factors and the hyperfine structure constants) and the local structure for the orthorhombic V4+ in CaYAlO4 are theoretically studied from the perturbation formulas of these parameters for a 3d1 ion in orthorhombically distorted octahedra. Based on the present studies, this center is explicitly assigned to V4+ occupying the Al3+ site, associated with one next‐nearest‐neighbor Mg2+ replacing the host Al3+ (i.e. MgAl) in the ab ‐plane due to the charge compensation. Since the effective charge of the compensator is negative (−e), the ligand O2− intervening in the impurity V4+ and the MgAl would undergo a small displacement (≈0.08 Å) towards the central ion because of the electrostatic repulsion. The local structure of this center can be described as elongation of the oxygen octahedron along the c‐ axis and the slight orthorhombic distortion in the perpendicular direction. The theoretical spin Hamiltonian parameters and the optical transitions based on the above local structure show reasonable agreement with the experimental data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The ‘hybrid cell’: a new compensated infinity cell for larger radius ion excitation in Fourier transform ion cyclotron resonance mass spectrometry
Authors: Kim Sunghwan , Choi Myoung Choul , Hur Manhoi , Kim Hyun Sik , Yoo Jong Shin , Hendrickson Christopher L. , Marshall Alan G.
Published: April 2008

A new ‘hybrid’ ion cyclotron resonance (ICR) trap is proposed and analyzed by computer simulations. The trap is basically a hybrid of a segmented end cap (Infinity) and capacitively coupled cylindrical cell, with additional electrodes placed at the center of each end cap. The new trap produces an on‐axis electric field z‐profile similar to that of the Infinity cell or capacitively coupled open cylindrical cell during ion excitation. Simion simulations demonstrate that, during detection, appropriate changes of the potentials applied to the two new sets of electrodes produce a radial electric field z‐profile that more closely approaches that for an ideal axial three‐dimensional quadrupolar potential at high post‐excitation ICR orbital radius, for improved signal‐to‐noise ratio and resolving power, and minimal m/z‐discrimination. Copyright © 2008 John Wiley & Sons, Ltd.
Quantitation of methylated hemoglobin adducts in a signature peptide from rat blood by liquid chromatography/negative electrospray ionization tandem mass spectrometry
Authors: Zhang Fagen , Bartels Michael J. , Pottenger Lynn H. , Schisler Melissa R. , Grundy Joy J. , Gollapudi B. Bhaskar
Published: April 2008

Hemoglobin adducts are often used as biomarkers for exposure to reactive chemicals in toxicology studies. Therefore, fast, sensitive, accurate, and reproducible methods for quantifying these protein adducts are key to evaluate test material dosimetry. A methodology has been developed for the quantitation of methylated hemoglobin adducts isolated from rats exposed to the model alkylating agent: methyl methane sulfonate (MMS). After 4 days of MMS exposure by oral gavage, hemoglobin was isolated from rat blood and digested with trypsin. The tryptic digestion solution was used for the adducted hemoglobin signature peptide quantitation via liquid chromatography/negative tandem mass spectrometry (LC/ESI‐MS/MS). The limit of quantitation (LOQ) for the methylated hemoglobin beta chain N‐terminal signature peptide (MeVHLTDAEK) was 1.95 ng/mL (5.9 pmol/mg globin). The calibration curves were linear over a concentration range of 1.95 to 625 ng/mL, with a correlation coefficient R2 >0.998, accuracy of 85.8 to 119.3%, and precision of 0.9 to 19.4%. Copyright © 2008 John Wiley & Sons, Ltd.
Plastische Tragfähigkeit von semi‐kompakten Querschnitten aus Stahl
Authors: Kettler Markus , Lechner Andreas , Greiner Richard
Published: April 2008

Semi‐kompakte Querschnitte sind jene, die in EN 1993‐1‐1 als Querschnitte der Klasse 3 definiert werden. Ihr Tragverhalten wird dort rein elastisch vorgegeben, wodurch sich ein abrupter Unstetigkeitssprung zum plastischen Tragverhalten der Klasse 2 einstellt. Die vorliegende Arbeit untersucht das teil‐plastische Verhalten dieses Querschnittsbereichs in Hinblick auf die Querschnittstragfähigkeit. Als Belastung werden Normalkraft, Biegung um die beiden Hauptachsen und deren Interaktion untersucht. Die Untersuchungen erfolgten sowohl experimentell als auch numerisch und führen auf einen Bemessungsvorschlag, unterlegt mit statistischen Auswertungen nach EN 1990.
Der Einfluss von Imperfektionen in dünnwandigen geschweißten Rechteckquerschnitten unter Druckbeanspruchung
Authors: Degée Hervé , Kuhlmann Ulrike , Detzel Annette , Maquoi René
Published: April 2008

Dieser Beitrag stellt die Ergebnisse eines Forschungsprojekts vor, in dem das Gesamtstabilitätsverhalten dünnwandiger geschweißter Rechteckhohlquerschnitte unter Druckbeanspruchung untersucht wurde. Um den Einfluss verschiedenartiger Imperfektionen, d. h. Eigenspannungen aus dem Schweißen und lokale wie globale geometrische Vorverformungen, auf die Traglast zu untersuchen, wurden umfangreiche experimentelle und numerische Untersuchungen durchgeführt. Aus den Erkenntnissen zum Tragverhalten wurden Empfehlungen für anzusetzende (Ersatz‐)Imperfektionen hergeleitet, die bei der numerischen Berechnung quadratischer und rechteckiger Hohlquerschnitte der Querschnittsklasse 4 unter Druckbeanspruchung verwendet werden sollten.
Zum zuverlässigkeitstheoretischen Konzept der Verbundträgerbemessung
Authors: Geißler Karsten , Heyde Stefan
Published: April 2008

Im Beitrag wird das Sicherheitskonzept zur Bemessung von Verbundträgern angesprochen. Dabei werden die sich für Verbundträger ergebenden Probleme aufgezeigt und diskutiert, dass eine Übertragung der an Bauteilen aus jeweils einem Werkstoff bewährten semiprobabilistischen Bemessungskonzepte nicht ohne Weiteres auf Verbund‐ bzw. Hybridbauteile möglich ist. Am Beispiel der “klassischen” Verbundträger werden für einfache Hochbauträger für den Spezialfall des starren Verbundes Ergebnisse von zahlreichen Berechnungen im Grenzzustand der Tragfähigkeit sowie der Gebrauchstauglichkeit dargestellt, die einzelnen Wertigkeiten der Eingangsparameter diskutiert und daraus abgeleitet die notwendigen Teil sicherheitsbeiwerte für diese Parameter begründet. Dabei werden bestimmte Modellungenauigkeiten am Querschnitt für die probabilistischen Berechnungen zunächst toleriert und der Fokus auf die Darstellung der zuverlässig‐keitstheoretischen Analyse gelegt.
Entwicklung eines allgemeinen Verfahrens für den Biegedrillknicknachweis von Verbundträgern im Bauzustand
Authors: Boissonnade Nicolas , Jaspart Jean‐Pierre , Haller Mike , Cajot Louis‐Guy , Weynand Klaus
Published: April 2008

In diesem Aufsatz wird eine neue Nachweismethode zur Überprüfung des Biegedrillknickverhaltens von Verbundträgern vorgestellt. Es wird eine neue Methode beschrieben, die auf der reduzierten Schlankheit gekoppelt mit dem Gebrauch von Knickkurven basiert. Dadurch gelingt es, die Momentengrenztragfähigkeit Mb,Rd zu bestimmen. Diese Methode wird als “hybrid” bezeichnet, da sie sich einerseits auf die analytisch berechneten Eigenschaften (Biegewiderstand) und andererseits auf numerische Rechnungen (kritisches Moment) stützt. Anschließend wird ausführlich über die Richtigkeit der Methode im Vergleich zu den Ergebnissen numerischer Simulationen berichtet. Außerdem werden Hilfswerkzeuge zur Dimensionierung vorgestellt. Schließlich wird die Software LATROCON (ACP) beschrieben. Sie ist gratis unter der Internetadresse www.arcelor.com/sections erhältlich.
X‐ray micro‐CT applied to natural building materials and art objects
Authors: De Witte Y. , Cnudde V. , Pieters K. , Masschaele B. , Dierick M. , Vlassenbroeck J. , Van Hoorebeke L. , Jacobs P.
Published: April 2008

In recent years, x‐ray micro‐CT has become an important tool for investigating all kinds of materials. The technique uses x‐ray transmission images of a sample to create a 3D representation of the specimen. Owing to its nondestructive nature, it is especially suited to investigate rare or expensive samples. This article aims to point out the potential x‐ray computed tomography (CT) has to offer to the preservation of cultural heritage and the world of art. Research was performed at the UGCT facility of the Ghent University (Belgium), using a ‘state of the art’ x‐ray microtomograph. In this article, the results for two applications of x‐ray CT are shown and discussed. The first application is the localization of salts in sandstone and limestone, as a contribution to the European Saltcontrol project. As for the second application, several bronze artifacts were scanned and reconstructed. This allows one to look at the interior composition of the sample and detect possible signs of reparation. Copyright © 2008 John Wiley & Sons, Ltd.
Hydrogen–deuterium exchange strategy for delineation of contact sites in protein complexes
Authors: Dyson H. Jane , Kostic Milka , Liu Jeff , Martinez-Yamout Maria A.
Published: April 2008

We use NMR spectra to determine protein–protein contact sites by observing differences in amide proton hydrogen–deuterium exchange in the complex compared to the free protein in solution. Aprotic organic solvents are used to preserve H/D labeling patterns that would be scrambled in water solutions. The binding site between the mammalian co‐chaperone Aha1 with the middle domain of the chaperone Hsp90 obtained by our H/D exchange method corresponds well with that in the X‐ray crystal structure of the homologous complex from yeast, even to the observation of a secondary binding site. This method can potentially provide data for complexes with unknown structure and for large or dynamic complexes inaccessible via NMR and X‐ray methods.
Neuronal nitric oxide synthase: Prototype for pulsed enzymology
Authors: Salerno John C.
Published: April 2008

The established pdigm in understanding and describing enzyme activity uses formalisms based on steady‐state assumptions, including Michaelis–Menten and King–Altman approaches. These are appropriate for enzymes operating under steady‐state conditions. Signal generating enzymes transfer information, rather than material. Because the information capacity of a signal channel depends on frequency, steady‐state descriptions may not be appropriate. Recently, Stuehr and coworkers described a novel product inhibition mechanism for NO synthases. Simulations presented here suggest that at physiological temperatures neuronal nitric oxide synthase produces sharp pulses of NO, consistent with its signaling function. These temporal pulses greatly restrict the effective spatial range of NO signaling.
Neurotrophin‐3 reduces apoptosis induced by 6‐OHDA in PC12 cells through Akt signaling pathway
Authors: Li Zhiquan , Hu Yunyu , Zhu Qingsheng , Zhu Jinyu
Published: April 2008

Previous work has demonstrated that 6‐hydroxydopamine (6‐OHDA) induces apoptosis in PC12 cells. The goal of the present study was to investigate the mechanisms underlying the protection by neurotrophin‐3 (NT‐3) against 6‐OHDA‐induced apoptosis in PC12 cells. Treatment of PC12 cells with 6‐OHDA resulted in activation of caspase‐3 and subsequent apoptosis, as detected by TUNEL staining. In addition, Akt phosphorylation was decreased following 6‐OHDA treatment. Pretreatment with NT‐3 reduced the percentage of apoptotic cells and caspase‐3 activity induced by 6‐OHDA and suppressed the cleavage of caspase‐3 and Poly(ADP‐ribose) polymerase (PARP) with a significant decrease in cell viability. Moreover, Akt phosphorylation was enhanced and 6‐OHDA‐induced chromatin condensation was suppressed by NT‐3. Such NT‐3‐evoked suppression in chromatin condensation was reversed by anti‐TrkA antibody receptor blockade. Further study revealed that LY294002, an inhibitor of PI3‐kinase (a molecule upstream of Akt), enhanced 6‐OHDA‐induced apoptosis. These data indicate that NT‐3 prevents 6‐OHDA‐induced apoptosis in PC12 cells via activation of PI3‐kinase/Akt pathway.