bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preventing galvanic corrosion – Systematic development of a magnesium car body component
Authors: Schreckenberger H. , Izquierdo P. , Klose S. G. , Blawert C. , Heitmann Volker , Höche D. , Kainer K. U. 
Published: October 2010

AbstractDie Rückwandtür des neuen Mercedes‐Benz E‐Klasse T‐Modells ist ein Beispiel für eine Hybridbauweise bestehend aus einem Innenteil aus Magnesiumdruckguss und einer Beplankung aus Aluminiumblech. Dabei muss das Bauteil eine Reihe von Anforderungen hinsichtlich Maßhaltigkeit, Gewicht, Steifigkeit, Crash‐ und Korrosionsverhalten erfüllen. Das Hybridkonzept im Allgemeinen, diverse Anbindungspunkte und Berührungsflächen erfordern eine sorgfältige Konstruktion, um Bimetallkorrosion zu vermeiden. Kritische Punkte werden angesprochen und anhand von zwei Beispielen (Gasdruckfeder und Türscharnier) werden die konstruktiven Kriterien diskutiert. Abschließend wird das Konzept der Korrosionsschutzmaßnahmen vorgestellt und Ergebnisse von verschiedenen Korrosions‐ und Funktionserprobungen präsentiert.The hatch back of the new Mercedes‐Benz E‐Class T‐Model is one example for a hybrid design with inner magnesium high pressure die casting liner and outer aluminium sheet. The hybrid lift gate has to fulfil a variety of requirements corresponding to dimensional stability, weight, stiffness, crash and corrosion performance. The hybrid concept in general as well as various interfaces and connecting points require a careful design to prevent galvanic corrosion. Critical points are introduced and for two examples (gas pressure spring and hinge) the constructive criterions are discussed. Finally, the concept of corrosion protection measures and results of various testing trials of the component are presented.
Interhemispheric motor networks are abnormal in patients with Gilles de la Tourette syndrome
Authors: Bäumer Tobias , Thomalla Götz , Kroeger Johan , Jonas Melanie , Gerloff Christian , Hummel Friedhelm Christoph , Müller‐Vahl Kirsten , Schnitzler Alfons , Siebner Hartwig Roman , Orth Michael , Münchau Alexander 
Published: October 2010

AbstractBrain imaging has shown altered corpus callosum (CC) morphology in patients with Gilles de la Tourette syndrome (GTS). Yet it is unclear whether these morphological changes are associated with altered interhemispheric interactions. Here, we combined transcranial magnetic stimulation (TMS) with diffusion tensor magnetic resonance imaging (DTI) to explore functional and structural interhemispheric connections between the left and right motor hand areas. We studied 14 unmedicated GTS patients without psychiatric comorbidity (2 women, mean age 35.5 years) and 15 healthy volunteers (3 women, mean age 35 years). Left‐to‐right and right‐to‐left interhemispheric inhibitions (IHIs) were measured in hand muscles with TMS. In 13 GTS patients and all healthy controls, we measured fractional anisotropy (FA) with DTI to examine the relation between functional measures of interhemispheric connectivity as derived by TMS and structural properties of the CC region that carries fibers interconnecting both motor cortices. In GTS patients, left‐to‐right IHI was weaker than right‐to‐left IHI. Left‐to‐right IHI in GTS patients was also reduced compared with healthy controls. Voxel‐based morphometric analysis revealed that FA in the motor region of the CC did not differ between groups. However, there was a significant interaction between groups and the relation between regional FA and left‐to‐right IHI in the motor region of the CC. A negative linear relation between FA and left‐to‐right IHI was present in control subjects but not in patients. Our combined TMS‐DTI approach demonstrates abnormal functional interhemispheric connectivity in GTS accompanied by an altered structure–function relationship in the motor CC. © 2010 Movement Disorder Society.
Simplified modeling approach suggests structural mechanisms for constitutive activation of the C5a receptor
Authors: Nikiforovich Gregory V. , Marshall Garland R. , Baranski Thomas J. 
Published: October 2010

AbstractMolecular modeling of conformational changes occurring in the transmembrane region of the complement factor 5a receptor (C5aR) during receptor activation was performed by comparing two constitutively active mutants (CAMs) of C5aR, NQ (I124N/L127Q), and F251A, to those of the wild‐type C5aR and NQ‐N296A (I124N/L127Q/N296A), which have the wild‐type phenotype. Modeling involved comprehensive sampling of various rotations of TM helices aligned to the crystal template of the dark‐adapted rhodopsin along their long axes. By assuming that the relative energies of the spontaneously activated states of CAMs should be lower or at least comparable to energies characteristic for the ground states, we selected the plausible models for the conformational states associated with constitutive activation in C5aR. The modeling revealed that the hydrogen bonds between the side chains of D82–N119, S85–N119, and S131–C221 characteristic for the ground state were replaced by the hydrogen bonds D82‐N296, N296‐Y300, and S131‐R134, respectively, in the activated states. Also, conformational transitions that occurred upon activation were hindered by contacts between the side chains of L127 and F251. The results rationalize the available data of mutagenesis in C5aR and offer the first specific molecular mechanism for the loss of constitutive activity in NQ‐N296A. Our results also contributed to understanding the general structural mechanisms of activation in G‐protein‐coupled receptors lacking the “ionic lock”, R3.50and E/D6.30. Importantly, these results were obtained by modeling approaches that deliberately simplify many elements in order to explore potential conformations of GPCRs involving large‐scale molecular movements. Proteins 2011. © 2010 Wiley‐Liss, Inc.
Exciton in a strained (001)‐oriented zinc‐blende GaN/AlxGa1‐xN ellipsoidal finite‐potential quantum dot under hydrostatic pressure
Authors: Shi Lei , Yan Zu Wei 
Published: October 2010

AbstractA variational method is used to discuss the binding energies of excitons in a strained zinc‐blende ellipsoidal quantum dot by considering the hydrostatic pressure effect. The analytic expressions for the Hamiltonian of the exciton have been obtained by using the Hylleraas coordinate system. The results indicate that the binding energies of excitons reach a peak value as the quantum dot radius increases and then diminish for the finite potential well. We show that the binding energies of excitons decrease with increasing ellipticity constant, but increase with pressure. In particular, it is found that the binding energies are more sensitive to the variations of the ellipticity constant for the small size of QD (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Probing the weakest bond and the cleavage ofp‐chlorobenzaldehyde diperoxide energetic molecule via quantum chemical calculations and theoretical charge density analysis
Authors: Stephen A. David , Revathi M. , Asthana S. N. , Pawar Rajesh B. , Kumaradhas P. 
Published: October 2010

AbstractA high‐level ab initio Hartree‐Fock/Møller‐Plesset 2 and density functional theory quantum chemical calculations were performed onp‐chlorobenzaldehyde diperoxide energetic molecule to understand its bond topological, electrostatic, and energetic properties. The optimized molecular geometry for the basis set 6‐311G** exhibit chair diperoxide ring and planar aromatic side rings. Although the diperoxide ring bear same type of side rings, surprisingly, both the rings are almost perpendicular to each other, and the dihedral angle is 96.1°. The MP2 method predicts the OO bond distance as ∼1.466 Å. The charge density calculation reveals that the CC bonds of chlorobenzaldehyde ring have rich electron density and the value is ∼2.14 e Å−3. The maximum electron density of the OO bonds does not lie along the internuclear axes; in view of this, a feeble density is noticed in the ring plane. The high negative values of laplacian of CC bonds (approximately −22.4 e Å−5) indicate the solidarity of these bonds, whereas it is found too small (approximately −1.8 e Å−5for MP2 calculation) in OO bonds that shows the existence of high degree of bond charge depletion. The energy density in all the CC bonds are found to be uniform. A high electronegative potential region is found at the diperoxide ring which is expected to be a nucleophilic attack area. Among the bonds, the OO bond charge is highly depleted and it also has high bond kinetic energy density; in consequence of this, the molecular cleavage is expected to happen across these bonds when the material expose to any external stimuli such as heat or pressure treatment. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Human Embryonic Stem Cells Suffer from Centrosomal Amplification
Authors: Holubcová Zuzana , Matula Pavel , Sedláčková Miroslava , Vinarský Vladimír , Doležalová Dáša , Bárta Tomáš , Dvořák Petr , Hampl Aleš 
Published: October 2010

AbstractPropagation of human embryonic stem cells (hESCs) in culture tends to alter karyotype, potentially limiting the prospective use of these cells in patients. The chromosomal instability of some malignancies is considered to be driven, at least in part, by centrosomal overamplification, perturbing balanced chromosome segregation. Here, we report, for the first time, that very high percentage of cultured hESCs has supernumerary centrosomes during mitosis. Supernumerary centrosomes were strictly associated with an undifferentiated hESC state and progressively disappeared on prolonged propagation in culture. Improved attachment to culture substratum and inhibition of CDK2 and Aurora A (key regulators of centrosomal metabolism) diminished the frequency of multicentrosomal mitoses. Thus, both attenuated cell attachment and deregulation of machinery controlling centrosome number contribute to centrosomal overamplification in hESCs. Linking the excessive number of centrosomes in mitoses to the ploidy indicated that both overduplication within a single cell cycle and mitotic failure contributed to generation of numerical centrosomal abnormalities in hESCs. Collectively, our data indicate that supernumerary centrosomes are a significant risk factor for chromosome instability in cultured hESCs and should be evaluated when new culture conditions are being implemented.
Local translation of mRNAs in neural development
Authors: Jung Hosung , Holt Christine E. 
Published: October 2010

AbstractGrowing axons encounter numerous developmental signals to which they must promptly respond in order to properly form complex neural circuitry. In the axons, these signals are often transduced into a local increase or decrease in protein levels. Contrary to the traditional view that the cell bodies are the exclusive source of axonal proteins, it is becoming increasingly clear not only that de novo protein synthesis takes place in axons, but also that it is required for the axons to respond to certain signals. Here we review the current knowledge of local mRNA translation in developing neurons with a special focus on protein synthesis occurring in axons and growth cones. WIREs RNA 2011 2 153–165 DOI: 10.1002/wrna.53This article is categorized under:

Translation > Translation Regulation
RNA Export and Localization > RNA Localization
RNA in Disease and Development > RNA in Development
N‐Acylated Bacteriohopanehexol‐Mannosamides from the Thermophilic Bacterium Alicyclobacillus acidoterrestris
Authors: Řezanka Tomáš , Siristova Lucie , Melzoch Karel , Sigler Karel 
Published: October 2010

AbstractIdentification of molecular species of various N‐acylated bacteriohopanehexol‐mannosamides from the thermophilic bacterium Alicyclobacillus acidoterrestris by semipreparative HPLC and by RP‐HPLC with ESI is described. We used triple‐quadrupole type mass spectrometer, 1H and 13C NMR for analyzing this complex lipid. CD spectra of two compounds (model compound—7‐deoxy‐d‐glycero‐d‐allo‐heptitol obtained by stereospecific synthesis, and an isolated derivative of hopane) were also measured and the absolute configuration of both compounds was determined. On the basis of all the above methods, we identified the full structure of a new class of bacteriohopanes, represented by various N‐acylated bacteriohopanehexol‐mannosamides.
Trust, autonomy and relationships: The help‐seeking preferences of young people in secondary level schools in London (UK)
Authors: Leavey Gerard , Rothi Despina , Paul Rini 
Published: October 2010

ABSTRACTHelp‐seeking among young people is complicated, often determined vicariously by the ability of adults, family or professionals, to recognize, and respond to, their difficulties. We know very little about the complex concerns of teenage young people and how they impact on help‐seeking preferences. We aimed to ascertain the help‐seeking preferences for a range of mental health problems among adolescents attending schools in an inner‐city area of London. In particular we sought to examine the relationship between such adolescents and their family doctor. Using a mixed methods approach we explored help‐seeking attitudes of young people. Emotional and mental health problems are not seen by young people as the domain of General practitioners. Moreover, there is a worrying lack of confidence and trust placed in family doctor and other professionals by young people. Young people do not tend easily to trust adults to help them with emotional difficulties.
Associations among sleep problems, learning difficulties and substance use in adolescence
Authors: Fakier Nuraan , Wild Lauren G. 
Published: October 2010

ABSTRACTThis study investigated the relationships among sleep problems, learning difficulties and substance use in adolescence. Previous research suggests that these variables share an association with executive functioning deficits, and are intertwined. The sample comprised 427 adolescents (M age = 16 years) attending remedial schools and 276 adolescents (M age = 15 years) attending a mainstream school in Cape Town, South Africa. Participants completed anonymous self‐report questionnaires. Results indicated that adolescents without learning difficulties were more likely to use tobacco, methamphetamine and cannabis, whereas those with learning difficulties engaged in more inhalant use. Adolescents who had more sleep problems were more likely to use tobacco, alcohol, methamphetamine, cannabis, inhalants, cocaine, ecstasy and any other illegal drug. Adolescents with learning difficulties had more sleep problems than those without learning difficulties. However, sleep problems remained independently associated with tobacco, cannabis and inhalant use when learning difficulties were taken into account.
Developmental and metabolic brain alterations in rats exposed to bisphenol A during gestation and lactation
Authors: Kunz Nicolas , Camm Emily Jane , Somm Emmanuel , Lodygensky Gregory , Darbre Stéphanie , Aubert Michel Lucien , Hüppi Petra Susan , Sizonenko Stéphane Vladimir , Gruetter Rolf 
Published: October 2010

AbstractIn recent years, considerable research has focused on the biological effect of endocrine‐disrupting chemicals. Bisphenol A (BPA) has been implicated as an endocrine‐disrupting chemical (EDC) due to its ability to mimic the action of endogenous estrogenic hormones.The aim of this study was to assess the effect of perinatal exposure to BPA on cerebral structural development and metabolism after birth.BPA (1 mg/l) was administered in the drinking water of pregnant dams from day 6 of gestation until pup weaning. At postnatal day 20, in vivo metabolite concentrations in the rat pup hippocampus were measured using high field proton magnetic resonance spectroscopy. Further, brain was assessed histologically for growth, gross morphology, glial and neuronal development and extent of myelination.Localized proton magnetic resonance spectroscopy (1H MRS) showed in the BPA‐exposed rat a significant increase in glutamate concentration in the hippocampus as well as in the Glu/Asp ratio. Interestingly these two metabolites are metabolically linked together in the malate–aspartate metabolic shuttle.Quantitative histological analysis revealed that the density of NeuN‐positive neurons in the hippocampus was decreased in the BPA‐treated offspring when compared to controls. Conversely, the density of GFAP‐positive astrocytes in the cingulum was increased in BPA‐treated offspring.In conclusion, exposure to low‐dose BPA during gestation and lactation leads to significant changes in the Glu/Asp ratio in the hippocampus, which may reflect impaired mitochondrial function and also result in neuronal and glial developmental alterations.
The mere association effect and brand evaluations
Authors: Dimofte Claudiu V. , Yalch Richard F. 
Published: October 2010

AbstractThe associative network model of memory proposes that each node (construct) belongs to specific networks of associations. These networks include nodes that share associations with a third (common) construct but are not themselves directly associated (merely associated nodes). The present research proposes that automatic associations between such indirectly related nodes can be primed in a single exposure and this may be sufficient to alter subsequent concept evaluations. An implicit cognition measure is used to demonstrate the automatic transfer of properties (both cognitive evaluations and affective responses) from a common associative node to seemingly unrelated objects. The effect is driven by individuals' inability to ignore activated but irrelevant associations. Results also show that the mere association effect and the underlying property transfer process (1) are more likely for consumers familiar with the concepts involved, (2) involve both cognitive and affective information, and (3) counterintuitively, occur more often for concepts from different categories rather than the same category.
Synergistic induction of apoptosis by the Bcl‐2 inhibitor ABT‐737 and imatinib mesylate in gastrointestinal stromal tumor cells
Authors: Reynoso David , Nolden Laura K. , Yang Dan , Dumont Sarah N. , Conley Anthony P. , Dumont Amaury G.P. , Zhou Kim , Duensing Anette , Trent Jonathan C. 
Published: October 2010

Background: Although imatinib mesylate has revolutionized the management of patients with gastrointestinal stromal tumor (GIST), resistance and progression almost inevitably develop with long‐term monotherapy. To enhance imatinib‐induced cytotoxicity and overcome imatinib‐resistance in GIST cells, we examined the antitumor effects of the pro‐apoptotic Bcl‐2/Bcl‐xL inhibitor ABT‐737, alone and in combination with imatinib.Methods: We treated imatinib‐sensitive, GIST‐T1 and GIST882, and imatinib‐resistant cells with ABT‐737 alone and with imatinib. We determined the anti‐proliferative and apoptotic effects by cell viability assay, flow cytometric apoptosis and cell cycle analysis, immunoblotting, and nuclear morphology. Synergism was determined by isobologram analysis.Results: The IC50 of single‐agent ABT‐737 at 72 h was 10 μM in imatinib‐sensitive GIST‐T1 and GIST882 cells, and 1 μM in imatinib‐resistant GIST48IM cells. ABT‐737 and imatinib combined synergistically in a time‐ and dose‐dependent manner to inhibit the proliferation and induce apoptosis of all GIST cells, as evidenced by cell viability and apoptosis assays, caspase activation, PARP cleavage, and morphologic changes. Isobologram analyses revealed strongly synergistic drug interactions, with combination indices <0.5 for most ABT‐737/imatinib combinations. Thus, clinically relevant in vitro concentrations of ABT‐737 have single‐agent antitumor activity and are synergistic in combination with imatinib.Conclusion: We provide the first preclinical evidence that Bcl‐2/Bcl‐xL inhibition with ABT‐737 synergistically enhances imatinib‐induced cytotoxicity via apoptosis, and that direct engagement of apoptotic cell death may be an effective approach to circumvent imatinib‐resistance in GIST.
Cochlear Implantation in Brown–Vialetto–Van-Laere syndrome
Authors: Sinnathuray A R , Watson D R , Fruhstorfer B , Olarte J R , Toner J G 
Published: October 2010

AbstractObjective:To report outcomes for the first known cochlear implantation procedures in two patients with Brown–Vialetto–Van-Laere syndrome.Patients:Two adult patients (a brother and sister) with post-lingual sensorineural deafness associated with Brown–Vialetto–Van-Laere syndrome. The female patient presented with a milder form of the syndrome.Intervention:Cochlear implantation.Main outcome measure:Post-implantation speech discrimination scores.Results:Auditory evoked potential testing suggested pathological changes in both patients' cochleae, auditory nerves, brainstem and (probably) central auditory pathways. In the male patient, despite implantation of the better ear, the Bamford–Kowal–Bench sentence score was zero at 21 months post-implantation. In the female patient, Bamford–Kowal–Bench sentence scores at six months post-implantation were 25 per cent in quiet and 3 per cent in noise.Conclusion:These poor clinical outcomes appear to be related to retrocochlear and probable central auditory pathway degeneration.
Serum matrix metalloproteinases and tympanosclerosis
Authors: Aslan H , Başoğlu M Sinan , Şentürk B , Özbay C , Katilmiş H , Öztürkcan S 
Published: October 2010

AbstractAim:To investigate levels of matrix metalloproteinases 2 and 9, and of their tissue inhibitor (i.e. tissue inhibitor matrix metalloproteinase 1), in the serum of patients with tympanosclerosis.Materials and method:We included 40 patients (age range 13–63 years) who had undergone surgery in the ENT department of İzmir Atatürk Training and Research Hospital between 2002 and 2007. Twenty had uncomplicated chronic otitis media and 20 had tympanosclerosis. We also included as the control group 20 individuals with no history of previous otic complaints or systemic or infectious disease. Serum levels of serum matrix metalloproteinases 2 and 9 and of tissue inhibitor matrix metalloproteinase 1 were measured in all subjects and compared.Result:Significantly higher levels of serum matrix metalloproteinases 2 and 9 were found in the tympanosclerosis group, compared with the chronic otitis media and control groups. There was no statistically significant difference in tissue inhibitor matrix metalloproteinase 1 level between the three groups.Conclusion:Tympanosclerosis surgery has poor success rates, since the pathological process is still active. We suggest that high levels of matrix metalloproteinases may play a role in the continuation of the disease process.