bluuebunny/crossref_metadata_2025_split huggingface dataset:
Progesterone regulates the phosphorylation of protein phosphatases in the brain
Authors: Amorim Miguel A.R. , Guerra‐Araiza Christian , Pernía Olga , da Cruz e Silva Edgar F. , Garcia‐Segura Luis M. 
Published: June 2010

AbstractPrevious studies have shown that progesterone modulates the activity of different kinases and the phosphorylation of Tau in the brain. These actions of progesterone may be involved in the hormonal regulation of neuronal differentiation, neuronal function, and neuroprotection. However, the action of progesterone on protein phosphatases in the nervous system has not been explored previously. In this study we have assessed the effect of the administration of progesterone to adult ovariectomized rats on protein phosphatase 2A (PP2A) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in the hypothalamus, the hippocampus, and the cerebellum. Total levels of PP2A, the state of methylation of PP2A, and total levels of PTEN were unaffected by the hormone in the three brain regions studied. In contrast, progesterone significantly increased the levels of PP2A phosphorylated in tyrosine 307 in the hippocampus and the cerebellum and significantly decreased the levels of PTEN phosphorylated in serine 380 in the hypothalamus and in the hippocampus compared with control values. Estradiol priming blocked the effect of progesterone on PP2A phosphorylation in the hippocampus and on PTEN phosphorylation in the hypothalamus and the hippocampus. In contrast, the action of progesterone on PP2A phosphorylation in the cerebellum was not modified by estradiol priming. These findings suggest that the regulation of the phosphorylation of PP2A and PTEN may be involved in the effects of progesterone on the phosphorylation of Tau and on the activity of phophoinositide‐3 kinase and mitogen‐activated protein kinase in the brain. © 2010 Wiley‐Liss, Inc.
Zinc signaling through glucocorticoid and glutamate signaling in stressful circumstances
Authors: Takeda Atsushi , Tamano Haruna 
Published: June 2010

AbstractHumans and animals are constantly exposed to environmental stress. The hypothalamic‐pituitary‐adrenal (HPA) axis responds to stress, followed by glucocorticoid secretion from the adrenal glands. This response serves to maintain homeostasis in the living body through energy mobilization or to restore it. The brain is an important target for glucocorticoids. The hippocampus participates in the regulation of the HPA axis. Stress activates glutamatergic neurons in the hippocampus, and serious stress induces dyshomeostasis of extracellular glutamate. This dyshomeostasis, which is potentiated by glucocorticoids, modifies cognitive and emotional behavior. On the other hand, zinc is necessary for glucocorticoid signaling and is released from glutamatergic (zincergic) neurons to modulate synaptic glutamate signaling. Stress also induces dyshomeostasis of extracellular zinc, which may be linked to dyshomeostasis of extracellular glutamate. Thus, glucocorticoid signaling might also contribute to dyshomeostasis of extracellular zinc. It is likely that zinc signaling participates in cognitive and emotional behavior through glucocorticoid and glutamate signaling under stressful circumstances. This Mini‐Review analyzes the relationship among signals of glucocorticoid, glutamate, and zinc under stressful circumstances to elucidate the significance of the zinc signaling in response to stress. © 2010 Wiley‐Liss, Inc.
Reliable and non‐destructive Raman analysis to determine the urea concentration in a cream formulation
Authors: Oh Changyong , Sriphong Lawan , Kim Minjung , Chung Hoeil , Asavapichayont Panida 
Published: June 2010

AbstractWe present a reliable and nondestructive analytical method for the determination of urea concentration in a pharmaceutical cream formulation using Raman spectroscopy. A pharmaceutical cream is a highly viscous emulsion; therefore, its composition and physical mixing could be inhomogeneous on a microscopic scale. The local environment around the urea could vary, which could influence the molecular vibrations of the urea molecule. As expected, when Raman spectra were collected by focusing the laser onto a tiny area (∼2–3 µm), the position of the urea band at 1003 cm−1 varied as a result of the microscopic inhomogeneity within the sample. Therefore, acquisition of Raman spectra representative of the entire sample rather than a localized portion of it is very important for the analysis of pharmaceutical creams. Based on the preliminary Raman mapping results of a urea cream, a sample area of at least 750 × 750 µm should be covered for reliable quantitative analysis. In this study, we used a wide‐area illumination scheme capable of covering a sample area of 28.3 mm2 for Raman spectral collection in order to ensure a reliable representative sample. In addition, to simplify the measurements, Raman spectra of urea creams in plastic bottles were directly collected without further sampling, and partial least squares regression was used for quantitative analysis. The urea concentrations were accurately determined despite the spectral collection being performed through plastic bottles. Copyright © 2010 John Wiley & Sons, Ltd.
Raman spectroscopic study of phase transitions in undoped morphotropic PbZr1−xTixO3
Authors: Deluca Marco , Fukumura Hideo , Tonari Nobuhiko , Capiani Claudio , Hasuike Noriyuki , Kisoda Kenji , Galassi Carmen , Harima Hiroshi 
Published: June 2010

AbstractSeveral PbZr1−xTixO3 (PZT) compositions in the proximity of the morphotropic phase boundary (MPB) were examined by means of Raman spectroscopy in the 15–800 K temperature range. Previous studies performed by other researchers using various techniques evidenced that, in the phase diagram of PZT, areas with rhombohedral/monoclinic and tetragonal/monoclinic phases coexist across the MPB. For these compositions, either long‐range or short‐range symmetry ordering of the monoclinic phase should be considered, so that no true rhombohedral–monoclinic–tetragonal phase boundary exists. In addition, the onset of antiferrodistortive phase transitions between high‐T and low‐T perovskite phases has been predicted by ab initio calculations and experimentally reported. In the present work, low‐T and high‐T Raman scattering spectra were collected on undoped PbZr1−xTixO3 with compositions x = 0.42, 0.45, 0.465, 0.48 and 0.53 in an attempt to clarify the current open issues on the phase diagram of PZT. Spectra clearly belonging to the respective phases were observed in the rhombohedral, monoclinic and tetragonal areas, thus confirming that monoclinic ordering is long‐range only for a narrow range of compositions. Raman measurements at cryogenic temperatures allowed detecting all predicted low‐T phases, including the tetragonal one. These results are in good agreement with both ab initio calculations and experimental results obtained by other authors on the same compositions. Copyright © 2010 John Wiley & Sons, Ltd.
Liquid chromatographic analysis of the anticancer alkaloid luotonin A and some new derivatives in human serum samples
Authors: González‐Ruiz Víctor , Mussardo Pierluigi , Corda Elisa , Girotti Stefano , Olives Ana I. , Martín María Antonia 
Published: June 2010

AbstractThe quantitation of the natural cytotoxic and anti‐inflammatory alkaloid luotonin A and five recently synthesized derivatives is described, constituting the first report of a HPLC method for the analysis of these compounds in human serum samples. The conditions for the chromatographic separation were optimized and the method was validated for the analysis of these compounds in biological samples according to international guidelines. An RP‐HPLC method with fluorimetric detection and a C18 stationary phase was applied. Different ACN/water mobile phases were assayed, including 0–4% of a mobile phase modifier such as tetrahydrofuran, dioxane or tert‐butyl methyl ether. Isocratic and gradient elution conditions are compared. The influence of pH on the efficiency and resolution of the separation was also considered. The developed method was applied to the determination of luotonins in pooled human serum samples by gradient elution RP‐HPLC using a simple cleanup procedure. The proposed chromatographic method exhibits satisfactory analytical figures of merit, with LOD from 1.0×10−10 to 2.0×10−10 M, intraday and interday precision below 6% except for the concentration level closest to LOD, and good agreement between experimental and theoretical concentrations. Therefore, the developed method is suitable, reliable, rapid, and simple.
Micro‐electrochemical characterization of galvanic corrosion of TA2/316L composite plate
Authors: Cheng X. , Li X. , Dong C. , Xiao K. 
Published: June 2010

AbstractGalvanic corrosion behavior of TA2/316L composite plate was investigated in the solution of 3.5 wt% NaCl by galvanic potential monitoring, scanning localized electrochemical impedance spectroscopy (LEIS) and scanning vibrating micro‐electrode (SVME) techniques. The results demonstrated that the pitting corrosion resistance of 316L for the galvanic combination sample is lower, and the coupled current density is higher than for the single 316L sample. It indicates that the galvanic action works on the corrosion behavior of the TA2 titanium alloy/316L stainless steel galvanic combination in sodium chloride solution. The galvanic effect width was determined as 1500 µm.
Relevance of the cathodic process on the passivation of stainless steels – an approximation to the origin of the rouging phenomenon
Authors: Klapper H. Sarmiento , Göllner J. , Heyn A. , Burkert A. 
Published: June 2010

AbstractUnwanted corrosive phenomena on stainless steel surfaces like rouging had been observed for years occurring at certain service conditions. Rouging consists in the formation of a colored surface film containing mainly iron on metallic surfaces in contact with high‐purity waters. In spite of numerous hypotheses and experimental examinations a clear explanation about the origin of rouging on stainless steels is currently still lacking. Because rouging occurs even at well passivated stainless steel surfaces the origin of this corrosive phenomenon should be related to the weakness of the stability of the passive film. In the present paper electrochemical noise measurements regarding the stability of the passive layer of alloy 904L (1.4539, X1NiCrMoCu25‐20‐5) in high‐purity water at 70 °C depending on the cathodic process are presented. In addition, the importance of the cathodic reaction on the passivation and stability of the passive layer is discussed.
Recent advances in understanding metal dusting: A review
Authors: Young D. J. , Zhang J. , Geers C. , Schütze M. 
Published: June 2010

AbstractRecent experimental investigations have widened the understanding of metal dusting significantly. Microscopic observations have been used to dissect dusting mechanisms. Iron dusts by growing a cementite surface scale, which catalyses graphite nucleation and growth. The resulting volume expansion leads to cementite disintegration. Cementite formation on iron can be suppressed by alloying with germanium. Nonetheless, dusting occurs via the direct growth of graphite into the metal, producing nanoparticles of ferrite. This process is faster, because carbon diffusion is more rapid in α‐Fe than in Fe3C. Austenitic materials cannot form cementite, and dust via formation of graphite at external surfaces and interior grain boundaries. The coke deposit consists of carbon nanotubes with austenite particles at their tips, or graphite particles encapsulating austenite. TEM studies demonstrate the inward growth of graphite within the metal interior. It is therefore concluded that the dusting mechanism of austenitic materials like high alloy Cr–Ni steels and Ni base materials is one of graphite nucleation and growth within the near surface metal. In all alloys examined, both ferritic and austenitic, the principal mass transfer process is inward diffusion of carbon. Alloying iron with nickel leads to a transformation from one mechanism with carbide formation to the other without. Copper alloying in nickel and high nickel content stainless steels strongly suppresses graphite nucleation, as does also an intermetallic Ni–Sn phase, thereby reducing greatly the overall dusting rate. A surface layer of intermetallic Ni–Sn Fe‐base materials facilitates the formation of a Fe3SnC surface scale which also prevents coking and metal dusting. Current understanding of the roles of temperature, gas composition and surface oxides on dusting rates are summarised. Finally, protection against metal dusting by coatings is discussed in terms of their effects on catalysis of carbon deposition, and on protective oxide formation.
A double‐blind, placebo‐controlled study to assess the mitochondria‐targeted antioxidant MitoQ as a disease‐modifying therapy in Parkinson's disease
Authors: Snow Barry J. , Rolfe Fiona L. , Lockhart Michelle M. , Frampton Christopher M. , O'Sullivan John D. , Fung Victor , Smith Robin A.J. , Murphy Michael P. , Taylor Kenneth M. ,   On behalf of the Protect Study Group
Published: June 2010

AbstractMultiple lines of evidence point to mitochondrial oxidative stress as a potential pathogenic cause for Parkinson's disease (PD). MitoQ is a powerful mitochondrial antioxidant. It is absorbed orally and concentrates within mitochondria where it has been shown to protect against oxidative damage. We enrolled 128 newly diagnosed untreated patients with PD in a double‐blind study of two doses of MitoQ compared with placebo to explore the hypothesis that, over 12 months, MitoQ would slow the progression of PD as measured by clinical scores, particularly the Unified Parkinson Disease Rating Scale. We showed no difference between MitoQ and placebo on any measure of PD progression. MitoQ does not slow the progression of PD, and this finding should be taken into account when considering the oxidative stress hypothesis for the pathogenesis of PD. © 2010 Movement Disorder Society
Increased reaction time predicts visual learning deficits in Parkinson's disease
Authors: Marinelli Lucio , Perfetti Bernardo , Moisello Clara , Di Rocco Alessandro , Eidelberg David , Abbruzzese Giovanni , Ghilardi Maria Felice 
Published: June 2010

AbstractTo determine whether the process involved in movement preparation of patients in the early stages of Parkinson's disease (PD) shares attentional resources with visual learning, we tested 23 patients with PD and 13 healthy controls with two different tasks. The first was a motor task where subjects were required to move as soon as possible to randomly presented targets by minimizing reaction time. The second was a visual learning task where targets were presented in a preset order and subjects were asked to learn the sequence order by attending to the display without moving. Patients with PD showed higher reaction and movement times, while visual learning was reduced compared with controls. For patients with PD, reaction times, but not movement times, displayed an inverse significant correlation with the scores of visual learning. We conclude that visual declarative learning and movement preparation might share similar attentional and working memory resources. © 2010 Movement Disorder Society
The prebiotic, oligofructose‐enriched inulin modulates the faecal metabolite profile: Anin vitroanalysis
Authors: De Preter Vicky , Falony Gwen , Windey Karen , Hamer Henrike M. , De Vuyst Luc , Verbeke Kristin 
Published: June 2010

AbstractScope:Health benefits of prebiotic administration have been judged mainly from the increased numbers of bifidobacteria and the enhanced production of short‐chain fatty acids in the colon. Only a few studies have focused on the capacity of prebiotics to decrease the proteolytic fermentation, which might contribute to health as well.Methods and results:The influence of the prebiotic oligofructose‐enriched inulin (OF‐IN) on the pattern of volatile organic compounds was characterized using anin vitrofaecal model. Faecal slurries, obtained from healthy subjects, were anaerobically incubated at 37°C with and without different doses of OF‐IN (2.5, 5, 10, or 20 mg) and changes in the metabolite pattern and pH were evaluated. A total of 107 different volatile organic compounds were identified and classified according to their chemical classes. The concentration of esters and acids significantly increased with increasing doses of OF‐IN. Similar effects were observed for some aldehydes. To the contrary, OF‐IN dose‐dependently inhibited the formation of S‐compounds. Also, the generation of other protein fermentation metabolites such as phenolic compounds was inhibited in the presence of OF‐IN.Conclusion:Our results confirmed a clear dose‐dependent stimulation of saccharolytic fermentation. Importantly, a significant decrease in toxic protein fermentation metabolites such as sulphides attended these effects.
Effect of exogenous DNA on bovine sperm functionality using the sperm mediated gene transfer (SMGT) technique
Authors: Canovas Sebastian , Gutierrez‐Adan Alfonso , Gadea Joaquin 
Published: June 2010

AbstractSperm mediated gene transfer (SMGT) could provide the opportunity to carry out transgenesis on a mass scale using spermatozoa as vectors for exogenous DNA. However, the efficiency of sperm‐mediated DNA transfer is still questionable, and the mode of transmission to the egg has not yet been well understood. Our aim was to investigate the capacity of bovine spermatozoa to carry exogenous DNA and its relationship to sperm functionality. We studied these parameters using flow cytometry to measure viability (necrosis and apoptosis) and capacitation status, computer‐assisted semen analysis (CASA) to measure motility parameters and in vitro fertilization (IVF) to assess fertilizing capacity. Furthermore, we studied the effect of capacitation status on interaction with exogenous DNA, and the role of heparin supplementation in this process. Bull spermatozoa showed a high capacity to bind DNA quickly and reached a maximum after 30 min, with approximately half of the DNA‐bound spermatozoa being viable. Incubation with exogenous DNA induced a decrease in sperm viability and motility and increased the proportion of apoptotic cells, but did not affect the cleavage rate in IVF assay. Heparin increased high‐lipid disorder and the number of sperm with DNA bound (viable and dead). In conclusion, this study shows that live spermatozoa can bind exogenous DNA with a slight negative effect in some parameters of sperm function that in our opinion, would not drastically compromise fertility. Mol. Reprod. Dev. 77: 687–698, 2010. © 2010 Wiley‐Liss, Inc.
Reactive extrusion of PLA and of PLA/carbon nanotubes nanocomposite: processing, characterization and flame retardancy
Authors: Bourbigot Serge , Fontaine Gaëlle , Gallos Antoine , Bellayer Séverine 
Published: June 2010

AbstractAliphatic polyesters such as polylactide (PLA) currently deserve particular attention in the area of environmentally degradable polymer materials. PLA is produced via polymerization of renewable products, namely lactic acid or lactide. In this work, the synthesis of PLA is done by reactive extrusion via ring opening polymerization of L,L‐lactide using a continuous single‐stage process which is a fast and an easy method. The resulting PLA is fully characterized by solid state NMR. It is shown that it exhibits properties similar to those of PLA synthesized by the traditional methods. A kinetic model based on a phenomenological approach permits one to describe the polymerization of L,L‐lactide. PLA nanocomposites containing multi‐wall carbon nanotube (MWNT) are also prepared by reactive extrusion. Reaction to fire of PLA nanocomposite shows a slight improvement of the flame retardancy. The nanodispersion characterized by transmission electronic microscopy (TEM) is acceptable but should be improved to obtain the best flame retardancy. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and optical properties of poly (vinyl acetate)/bismuth oxide nanorods
Authors: Mahmoud Waleed E. , Al‐Ghamdi A. A. , Al‐Agel F. 
Published: June 2010

AbstractPoly (vinyl acetate) (PVAc) loaded bismuth oxide (Bi2O3) nanorods were successfully prepared at ambient pressure. X‐ray diffraction (XRD) and transmission electron microscopy were used to characterize the final product. It was found that Bi2O3 nanorods were formed and the diameter of the rods was confined to about 8 nm. The diameter and length of formed rods were found to increase by increasing the bismuth oxide concentration in the PVAc matrix. The optical properties of the nanocomposite films were characterized from the analysis of the experimentally recorded transmittance and reflectance data in the spectral wavelength range of 300–800 nm. The values of some important parameters of the studied films are determined such as refractive index (n), extinction coefficient (k), optical absorption coefficient (α), and band energy gap (Eg). According to the analysis of dispersion curves, it has been found that the dispersion data obeyed the single oscillator of the Wemple–DiDomenico model, from which the dispersion parameters and high‐frequency dielectric constant were determined. In such work, from the transmission spectra, the dielectric constant (ε∞) and the third‐order optical nonlinear susceptibility χ(3) were determined. Copyright © 2010 John Wiley & Sons, Ltd.
Study on the friction and wear behavior of surface‐modified carbon nanotube filled carbon fabric composites
Authors: Zhang Xinrui , Pei Xianqiang , Wang Qihua 
Published: June 2010

AbstractThe functionalization of multi‐walled carbon nanotubes (MWNTs) was achieved by grafting furfuryl amine (FA) onto the surfaces of MWNTs. Furthermore, the functional MWNTs were incorporated into carbon fabric composites and the tribological properties of the resulting composites were investigated systematically on a model ring‐on‐block test rig. Friction and wear tests revealed that the modified MWNTs filled carbon fabric composite has the highest wear resistance under all different sliding conditions. Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and thermal gravimetric analysis (TGA) revealed that MWNTs were successfully functionalized and the modification led to an improvement in the dispersion of MWNTs, which played an important role on the enhanced tribological properties of carbon fabric composites. It can also be found that the friction and wear behavior of MWNTs filled carbon fabric composites are closely related with the sliding conditions such as sliding speed, load, and lubrication conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Multifunctional PES fabrics modified with colloidal Ag and TiO2nanoparticles
Authors: Mihailović Darka , Šaponjić Zoran , Vodnik Vesna , Potkonjak Branislav , Jovančić Petar , Nedeljković Jovan M. , Radetić Maja 
Published: June 2010

AbstractThis study is aimed to highlight the possibility of engineering the multifunctional textile nanocomposite material based on the polyester (PES) fabric modified with colloidal Ag and TiO2nanoparticles (NPs). The effects of concentration of NPs as well as the order of Ag and TiO2NPs loading on antimicrobial, UV protective, and photocatalytic properties of PES fabrics were examined. The antimicrobial activity of differently modified PES fabrics was tested against Gram‐negative bacteriumEscherichia coli, Gram‐positive bacteriumStaphylococcus aureus, and fungusCandida albicans. The concentration of Ag colloid and the order of Ag and TiO2NPs loading considerably affected the antimicrobial efficiency of PES fabrics. The fabrics provided maximum UV protection upon surface modification with Ag and TiO2NPs. Ag NPs enhanced Ag NPs enhanced the photodegradation activity of TiO2NPs and total photodegradation of methylene blue was achieved after 24 hr of UV illumination. Copyright © 2010 John Wiley & Sons, Ltd.