bluuebunny/crossref_metadata_2025_split huggingface dataset:
Verification of effect of damper windings on the transient condition of synchronous generator
Authors: Matsuki Junya , Taoka Hisao , Hayashi Yasuhiro , Iwamoto Shigeru , Daikoku Akihiro 
Published: April 2012

AbstractThis paper describes the results of an experimental investigation on the effects of the damper winding of a four‐pole synchronous generator at a synchronous generator transient. It is known from simulations that the damper winding acts effectively under synchronous generator transient conditions. However, experimental proof has not been obtained yet. Thus, experiments on damper effects were conducted using a laboratory‐scale power system. The damper winding of the tested generator consisted of five damper bars for each pole; the number of working damper bars could be changed manually. The damper currents at each bar were measured by a Rogowski coil. FFT analysis was applied to both the damper currents and armature currents under different operating conditions. The relationships between damper currents in the rotor and armature currents in the stator were made clearer than before. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(2): 33–42, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21278
Simulation of the effects of complex‐ formation equilibria in electrophoresis: II. Experimental verification
Authors: Svobodová Jana , Beneš Martin , Hruška Vlastimil , Ušelová Kateřina , Gaš Bohuslav 
Published: April 2012

The complete mathematical model of electromigration in systems with complexation agents introduced in the Part I of this article (V. Hruška et al., Eletrophoresis, 2012, 33, this issue), which was implemented into our simulation program Simul 5, was verified experimentally. Three different chiral selector (CS) systems differing in the type of the CS, the magnitude of the complexation constants as well as in the experimental conditions were selected for verification. The experiments and simulations were performed at various concentrations of the CSs in order to discuss the influence of the concentration of the CS on the separation. The simulated and experimental electropherograms show very good agreement in the position, shape and amplitude of the analyte peaks.The new Simul 5 Complex offers a deep insight into electrophoretical separations that take place in systems containing complexing agents, for example into enantiomer separations. Using Simul 5 Complex we were able to predict and explain the significant electromigration dispersion of analyte peaks. It was clarified that the electromigration dispersion in these systems results directly from complexation. The new Simul 5 Complex was also shown to be a useful and powerful tool for the prediction of the results of enantioseparations.
Small cell lung cancer tumour cells induce regulatory T lymphocytes, and patient survival correlates negatively with FOXP3+ cells in tumour infiltrate
Authors: Wang Wei , Hodkinson Philip , McLaren Fiona , MacKinnon Alison , Wallace William , Howie Sarah , Sethi Tariq 
Published: April 2012

AbstractSmall cell lung cancer (SCLC) kills at least one person every 2 hr in the United Kingdom. Some patients do relatively well but most have rapidly progressive disease. There is no effective treatment and overall 2‐year survival is less than 5%. Patients with SCLC have poorly understood local and systemic immune defects and can be immunocompromised. As CD4+ T lymphocytes coordinate and regulate immunity, a better understanding of interactions between SCLC tumour cells and CD4+ T cells may lead to effective molecular immunotherapy. We show that some, but not all, SCLC tumour cell lines secrete molecules that induce IL‐10 secretion by and de novo differentiation of functional CD4+CD25+FOXP3+CD127loHelios− regulatory T (Treg) cells in healthy blood lymphocytes. FOXP3+ T cells were found in SCLC tumour biopsies, and patients with higher ratios of FOXP3+ cells in tumour infiltrates have a worse survival rate. The inhibitory effect of SCLC tumour cells was not affected by blocking IL‐10 receptor or TGF‐β signalling but was partially reversed by blocking IL‐15, which is reported to be involved in human Treg cells induction. IL‐15 was secreted by SCLC cells that inhibited CD4+ T‐cell proliferation and was present in SCLC biopsy tumour cells. These novel findings demonstrate that SCLC tumour cells can induce CD4+ T‐cell‐mediated immunosuppression. This gives a potential mechanism by which SCLC tumour cells may downregulate local and systemic immune responses and contribute to poor patient survival. Our data suggest that IL‐15 and Treg cells are potential new therapeutic targets to improve immune response and patient survival in SCLC.
Gastric stump cancer after distal gastrectomy for benign gastric ulcer in a population‐based study
Authors: Lagergren Jesper , Lindam Anna , Mason Robert M. 
Published: April 2012

AbstractThe risk of cancer in the gastric remnant after distal gastrectomy for benign ulcer disease has been assessed mainly in studies of small sample size, selected series and limited follow‐up time. This was a population‐based cohort study of patients who had undergone distal gastrectomy for benign ulcer disease in 1964–2008 in Sweden. Data for follow‐up for cancer and censoring for death were obtained from nationwide registries of Cancer and Population, respectively. The number of observed cancer cases in the gastrectomy cohort was divided by the expected number, calculated from the cancer incidence of the Swedish population of corresponding age, sex and calendar year. Relative risks were presented as standardized incidence ratios (SIRs) with 95% confidence intervals (CIs). The distal gastrectomy cohort included 18,912 patients and 323,676 person‐years at risk. The observed total number of gastric stump cancers (n = 140) was not higher than expected (SIR 0.84, 95% CI 0.71–0.99). There was no increased SIR with latency periods shorter than 30 years; increase was seen only among patients who had undergone gastric resection over 30 years earlier (SIR 2.29, 95% CI 1.38–3.57). Sex, age, ulcer location and type of surgical reconstruction were not associated with any considerable differences in SIR. In conclusion, this large population‐based study revealed an increased risk of cancer in the gastric remnant only 30 years or longer after gastric resection for benign disease, whereas other factors did not influence this risk.
On the origin of the 1602 cm–1 Raman band of yeasts; contribution of ergosterol
Authors: Chiu Liang‐da , Hullin‐Matsuda Françoise , Kobayashi Toshihide , Torii Hajime , Hamaguchi Hiro‐o 
Published: April 2012

AbstractThe 1602 cm–1 Raman signature, which we call the “Raman spectroscopic signature of life” in yeasts, is a marker Raman band for cell metabolic activity. Despite the established fact that its intensity sensitively reflects the metabolic status of the cell, its molecular origin remained unclear. In this work, we propose ergosterol as the major contributor of the 1602 cm–1 Raman signature. The theoretical isotope shift calculation for ergosterol agreed with previous observations. Furthermore, experiments showed that the Raman spectrum of ergosterol corresponds very well with the depleting spectral component in yeast that behaves together with the 1602 cm–1 signature when the cells are under stress. This work implies that the 1602 cm–1 Raman signature could serve as an intrinsic ergosterol marker in yeasts for the study of sterol metabolism in vivo and in a label‐free manner, which could not be done by any other techniques at the current stage. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of Cu(II)‐loaded brushite scaffolds on growth and activity of osteoblastic cells
Authors: Ewald Andrea , Käppel Christine , Vorndran Elke , Moseke Claus , Gelinsky Michael , Gbureck Uwe 
Published: April 2012

AbstractBone substitute materials such as calcium phosphate cements (CPC) are frequently used as growth factor carriers for the stimulation of osteoblast‐formation around an implant. However, biological modification based on delicate protein factors like extracellular matrix proteins or growth factors is subject to a number of shortcomings like the need for storage below room temperature and cost of production. The aim of this study was to investigate ionic modification as an alternative bioinorganic route for implant modification. Although it is known that Cu(II) plays a role in angiogenesis and bone formation, not all involved processes are well understood yet. In this study the in vitro effect of Cu(II) on growth and activity of osteoblastic cells seeded on brushite (CaHPO4 · 2 H2O) scaffolds as well as on glass discs was investigated. The results show that Cu(II) enhances cell activity and proliferation of osteoblastic cells on CPC and furthermore affects the expression of several bone specific proteins such as bone sialo protein or osteocalcin. Therefore, the modification of CPC with Cu(II) may offer a promising alternative to protein based modification to stimulate cellular activity for an improved bone healing. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2392–2400, 2012.
Empirical van der Waals corrections to solid‐state density functional theory: Iodine and phosphorous containing molecular crystals
Authors: Kendrick John , Leusen Frank J. J. , Neumann Marcus A. 
Published: April 2012

AbstractParameters are derived for a molecular mechanics type dispersive correction to solid‐state density functional theory calculations on molecular crystals containing iodine and phosphorous. The molecular C6 coefficients are derived from photoabsorption differential oscillator strength spectra determined from accurate (e,e) dipole spectra. The cross‐over parameters, which ensure correct behavior at short internuclear distances, are obtained by fitting predicted crystal lattice parameters to experimental data. The accuracy of the parameterization is assessed by optimizing the experimental structures of several additional phosphorous and iodine containing molecular crystals and by examining the relative stabilities of the known polymorphs of phosphorous pentoxide and the stabilities of different packings of an iodine containing molecular crystal, 2,9‐bis(iodo)anthanthrone, which has been the subject of a crystal structure prediction study. Optimizations of the experimental crystal structures did not lead to significant geometric deviations. The optimized experimental structure of 2,9‐bis(iodo)anthanthrone is the lowest energy packing found, indicating a satisfactory description of both energy and structure for these molecular crystals. © 2012 Wiley Periodicals, Inc.
Uterine Epithelial Morphology and Progesterone Receptors in a Mifepristone‐treated Viviparous Lizard Pseudemoia entrecasteauxii (Squamata: Scincidae) During Gestation
Authors: BIAZIK JOANNA M. , PARKER SCOTT L. , MURPHY CHRISTOPHER R. , THOMPSON MICHAEL B. 
Published: April 2012

ABSTRACTStructural and functional changes to the uterus associated with maintenance of pregnancy are controlled primarily by steroid hormones such as progesterone. We tested the hypothesis that progesterone regulates uterine structural changes during pregnancy in the viviparous skink, Pseudemoia entrecasteauxii, by treating pregnant females with the progesterone receptor antagonist mifepristone at different stages of pregnancy. Expression and distribution of progesterone receptor was determined using Western blot and immunohistochemistry. During early pregnancy, mifepristone treatment resulted in altered uterine epithelial cell surface morphology and high embryo mortality, but did not affect females at mid and late stages of pregnancy. Females treated with mifepristone in early pregnancy exhibited abnormal uterine epithelial cell morphology such as lateral blebbing and presence of wide gaps between cells indicating loss of intercellular attachment. Chorioallantoic membranes of the embryo were not affected by mifepristone treatment. Two isoforms (55 kDa and 100 kDa) of progesterone receptor were identified using immunoblots and both isoforms were localized to the nucleus of uterine epithelial cells. The 55 kDa isoform was expressed throughout pregnancy, whereas the 100 kDa isoform was expressed during mid and especially late pregnancy. In P. entrecasteauxii, mifepristone may prevent successful embryo attachment in early pregnancy through its effects on uterine epithelial cells but may have little effect on pregnancy once the maternal‐embryo structural relationship is established. J. Exp. Zool. (Mol. Dev. Evol.) 318:148–158, 2012. © 2012 Wiley Periodicals, Inc.
Dynamic expression of Pax6 in the shark olfactory system: evidence for the presence of Pax6 cells along the olfactory nerve pathway
Authors: Ferreiro‐Galve Susana , Candal Eva , Rodríguez‐Moldes Isabel 
Published: April 2012

AbstractPax6 is involved in the control of neuronal specification, migration, and differentiation in the olfactory epithelium and in the generation of different interneuron subtypes in the olfactory bulb. Whether these roles are conserved during evolution is not known. Cartilaginous fish are extremely useful models for assessing the ancestral condition of brain organization because of their phylogenetic position. To shed light on the evolution of development of the olfactory system in vertebrates and on the involvement of Pax6 in this process, we analyzed by in situ hybridization and immunohistochemistry the expression pattern of Pax6 in the developing olfactory system in a basal vertebrate, the lesser spotted dogfish Scyliorhinus canicula. This small shark is becoming an important fish model in studies of vertebrate development. We report Pax6 expression in cells of the olfactory epithelium and olfactory bulb, and present the first evidence in vertebrates of strings of Pax6‐expressing cells extending along the developing olfactory nerve. The results indicate the olfactory epithelium as the origin of these cells. These data are compatible with a role for Pax6 in the development of the olfactory epithelium and fibers, and provide a basis for future investigations into the mechanisms that regulate development of the olfactory system throughout evolution. J. Exp. Zool. (Mol. Dev. Evol.) 318:79–90, 2012. © 2011 Wiley Periodicals, Inc.
Force volume and stiffness tomography investigation on the dynamics of stiff material under bacterial membranes
Authors: Longo Giovanni , Rio Laura Marques , Roduit Charles , Trampuz Andrej , Bizzini Alain , Dietler Giovanni , Kasas Sandor 
Published: April 2012

The determination of the characteristics of micro‐organisms in clinical specimens is essential for the rapid diagnosis and treatment of infections. A thorough investigation of the nanoscale properties of bacteria can prove to be a fundamental tool. Indeed, in the latest years, the importance of high resolution analysis of the properties of microbial cell surfaces has been increasingly recognized. Among the techniques available to observe at high resolution specific properties of microscopic samples, the Atomic Force Microscope (AFM) is the most widely used instrument capable to perform morphological and mechanical characterizations of living biological systems. Indeed, AFM can routinely study single cells in physiological conditions and can determine their mechanical properties with a nanometric resolution. Such analyses, coupled with high resolution investigation of their morphological properties, are increasingly used to characterize the state of single cells.In this work, we exploit the capabilities and peculiarities of AFM to analyze the mechanical properties of Escherichia coli in order to evidence with a high spatial resolution the mechanical properties of its structure. In particular, we will show that the bacterial membrane is not mechanically uniform, but contains stiffer areas. The force volume investigations presented in this work evidence for the first time the presence and dynamics of such structures. Such information is also coupled with a novel stiffness tomography technique, suggesting the presence of stiffer structures present underneath the membrane layer that could be associated with bacterial nucleoids. Copyright © 2012 John Wiley & Sons, Ltd.
Optically detected magnetic resonance studies of luminescence‐quenching processes in π‐conjugated materials and organic light‐emitting devices
Authors: Shinar J. 
Published: April 2012

AbstractIt is widely recognized that nonradiative quenching of excitons by other excitons and polarons become the dominant decay mechanism of these excitons at high excitation densities. These quenching processes cause the roll‐off in the efficiency of organic light‐emitting devices (OLEDs) and prevent lasing at high injection current densities. This review presents the optically‐detected magnetic resonance (ODMR) evidence for these photoluminescence‐ and electroluminescence‐quenching processes. And while it provides such evidence for quenching of singlet excitons by polarons and triplet excitons, it reveals the central role of the strongly spin‐dependent annihilation of triplet excitons by polarons, since under normal excitation conditions the steady‐state polaron and triplet exciton populations are 100–104 times the singlet exciton population. In addition, it also suggests that quenching of singlet excitons by bipolarons, likely stabilized by a counterpolaron or countercharge at specific sites, may also be a significant quenching mechanism that also affects the charge transport properties.
Co(acac)2‐Mediated Radical Polymerization of Acrylonitrile: Control Over Molecular Weights and Copolymerization With Methyl Methacrylate
Authors: Buchmeiser Michael R. , Marino Michael G. 
Published: April 2012

AbstractThe cobalt‐mediated radical polymerization of acrylonitrile in DMSO using cobalt (II) acetylacetonate [Co(acac)2] as mediator is studied. Both the evolution of molecular weight and conversion over time under various conditions are monitored. Molecular weights increase sharply at the beginning of the reaction and subsequently grow linearly with conversion. No branching of the polymer is observed by 13C NMR. By a careful design of the reaction parameters, number‐average molecular weights >1.2 · 105 g · mol−1 with a PDI around 2.4 together with conversions of up to 90% within 24 h are achieved. The copolymerization parameters of acrylonitrile with methyl methacrylate in DMSO at 30 °C are determined using the Kelen‐Tüdõs approach giving rAN = 0.33, rMMA = 0.71.magnified image
Transforming Frozen Self‐Assemblies of Amphiphilic Block Copolymers Into Dynamic pH‐Sensitive Micelles
Authors: Dutertre Fabien , Boyron Olivier , Charleux Bernadette , Chassenieux Christophe , Colombani Olivier 
Published: April 2012

AbstractThe self‐assembly in water of an amphiphilic P(nBMA50%‐stat‐DMAEMA50%)100‐b‐PDMAEMA235 diblock copolymer based on hydrophilic dimethylaminoethylmethacrylate (DMAEMA) units and hydrophobic n‐butylmethacrylate (nBMA) ones is reported. DMAEMA units have been incorporated into the hydrophobic block of this copolymer to moderate its hydrophobic character. Light scattering experiments revealed the formation of micelles whose apparent aggregation number varied reversibly with the ionization degree of the DMAEMA units. Incorporating hydrophilic units into the hydrophobic block of an amphiphilic block copolymer is thus a way to generate dynamic aggregates in aqueous medium. As this strategy was also successful using other types of hydrophilic units, we believe it to be universal.
Endoplasmic reticulum stress is involved in granulosa cell apoptosis during follicular atresia in goat ovaries
Authors: Lin Pengfei , Yang YanZhou , Li Xiao , Chen Fenglei , Cui ChenChen , Hu Linyong , Li Qian , Liu Wei , Jin YaPing 
Published: April 2012

AbstractFollicular atresia is primarily induced by granulosa cell apoptosis, but description of the apoptotic pathway in granulosa cells is incomplete. In this study, we explored the possibility that endoplasmic reticulum (ER) stress could be involved in granulosa cell apoptosis during goat follicular atresia. Immunohistochemical analysis revealed that DNA damage‐inducible transcript 3 (DDIT3) and glucose‐regulated protein 78 (Grp78) were observed in scattered apoptotic granulosa cells of atretic follicles. Grp78 and DDIT3 mRNA and protein were upregulated in granulosa cells during follicular atresia, although DDIT3 was not significantly different between early atretic and progressed atretic follicles. Spontaneous apoptosis was also observed in vitro in granulosa cells induced by serum deprivation or by the ER stress agent tunicamycin, both inducing similar increases in DDIT3 mRNA. Activating transcription factor‐6 (ATF6) and ATF4 mRNAs were significantly increased during granulosa cell apoptosis in vivo; in contrast to ATF6, ATF4 mRNA was attenuated after 16 hr of culture despite the persistence of ER stress. Taken together, ER stress‐dependent DDIT3 pathways may play an important role in the regulation of selective granulosa cell apoptosis in goat ovaries during early follicular atresia. Serum deprivation could also increase apoptosis of cultured granulosa cells through the ER stress pathway as both ATF6 and PERK/eIF2α/ATF4 signaling have been implicated in the granulosa cell apoptosis of atretic follicles. Mol. Reprod. Dev. 79:423–432, 2012. © 2012 Wiley Periodicals, Inc.
Perfusion phantom: An efficient and reproducible method to simulate myocardial first‐pass perfusion measurements with cardiovascular magnetic resonance
Authors: Chiribiri Amedeo , Schuster Andreas , Ishida Masaki , Hautvast Gilion , Zarinabad Niloufar , Morton Geraint , Otton James , Plein Sven , Breeuwer Marcel , Batchelor Philip , Schaeffter Tobias , Nagel Eike 
Published: April 2012

AbstractThe aim of this article is to describe a novel hardware perfusion phantom that simulates myocardial first‐pass perfusion allowing comparisons between different MR techniques and validation of the results against a true gold standard. MR perfusion images were acquired at different myocardial perfusion rates and variable doses of gadolinium and cardiac output. The system proved to be sensitive to controlled variations of myocardial perfusion rate, contrast agent dose, and cardiac output. It produced distinct signal intensity curves for perfusion rates ranging from 1 to 10 mL/mL/min. Quantification of myocardial blood flow by signal deconvolution techniques provided accurate measurements of perfusion. The phantom also proved to be very reproducible between different sessions and different operators. This novel hardware perfusion phantom system allows reliable, reproducible, and efficient simulation of myocardial first‐pass MR perfusion. Direct comparison between the results of image‐based quantification and reference values of flow and myocardial perfusion will allow development and validation of accurate quantification methods. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Reducing localized signal fluctuation in fMRI using spectral–spatial fat saturation
Authors: Xu Dan , Hinks R. Scott , King Kevin F. 
Published: April 2012

AbstractConventional 1D, spatially nonselective fat saturation can generate uncrushed fat signals in areas far outside the imaging slice where crushers are weak because of reduced gradient linearity. These fat signals can corrupt in‐slice water signal, and in functional MRI, they can manifest themselves as artifacts such as clouds in image background or localized signal fluctuation over time. In this article, a spectral–spatial radiofrequency pulse is proposed to replace the conventional, spatially nonselective fat saturation pulse. The advantage of the proposed method is that fat protons far outside the image slice would not be excited because of the spatial selectivity, thereby removing the root cause of the fat aliasing artifacts. The proposed method also preserves thin slice capability, pulse duration, and fat suppression performance of the conventional method. Bloch simulation and human volunteer results show that the method is effective in reducing the fat aliasing artifacts seen in functional MRI. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.