bluuebunny/crossref_metadata_2025 huggingface dataset:
An 18‐month study of the safety and efficacy of repeated courses of inhaled aztreonam lysine in cystic fibrosis
Authors: Oermann Christopher M. , Retsch‐Bogart George Z. , Quittner Alexandra L. , Gibson Ronald L. , McCoy Karen S. , Montgomery A. Bruce , Cooper Peter J.
Published: July 2010

Chronic airway infection with Pseudomonas aeruginosa (PA) causes morbidity and mortality in patients with cystic fibrosis (CF). Additional anti‐PA therapies are needed to improve health status and health‐related quality of life. AIR‐CF3 was an international 18‐month, open‐label study to evaluate the safety and efficacy of repeated courses of aztreonam for inhalation solution (AZLI, now marketed as Cayston®) in patients aged ≥6 years with CF and PA infection who previously participated in one of two Phase 3 studies: AIR‐CF1 or AIR‐CF2. Patients received up to nine courses (28 days on/28 days off) of 75 mg AZLI two (BID) or three times daily (TID) based on randomization in the previous trials. 274 patients, mean age 28.5 years (range: 8–74 years), participated. Mean treatment adherence was high (92.0% BID group, 88.0% TID group). Hospitalization rates were low and adverse events were consistent with CF. With each course of AZLI, FEV1 and scores on the Cystic Fibrosis Questionnaire‐Revised Respiratory Symptom scale improved and bacterial density in sputum was reduced. Benefits waned in the 28 days off therapy, but weight gain was sustained over the 18 months. There were no sustained decreases in PA susceptibility. A dose response was observed; AZLI TID‐treated patients demonstrated greater improvements in lung function and respiratory symptoms over 18 months. Repeated intermittent 28‐day courses of AZLI treatment were well tolerated. Clinical benefits in pulmonary function, health‐related quality of life, and weight were observed with each course of therapy. AZLI is a safe and effective new therapy in patients with CF and PA airway infection. Pediatr Pulmonol. 2010;45:1121–1134. © 2010 Wiley‐Liss, Inc.
The promise and realities of comparative effectiveness research
Authors: Gatsonis Constantine
Published: July 2010

Comparative Effectiveness Research (CER) has been given a broad and ambitious mandate. Will it be able to deliver the multifaceted and granular comparative information that it has been tasked with developing? After a discussion of the general conditions for the feasibility of CER, we focus our attention on one of the most challenging areas: the evaluation of diagnostic tests and biomarkers. Copyright © 2010 John Wiley & Sons, Ltd.
Thixocasting Steel Hand Tools using Al2O3‐coated Steel and Molybdenum Dies
Authors: Bünck M. , Subasic E. , Bührig‐Polaczek A. , Jiang K. , Münstermann S. , Schneider J. M. , Fickert K. , Günther H.‐J.
Published: July 2010

Forging is state‐of‐the‐art for producing hand tools on an industrial scale. Due to high demands on the stiffness and the fracture toughness, high‐strength forging steels are used to provide cavity‐free components with high mechanical load capacity. Moreover, forging is a cost‐effective mass production process but, in spite of all its advantages, it has its limitations, e.g. in the freedom of designs. However, because of the extreme thermal loading (particularly with regard to permanent moulds) and the frequently unavoidable casting defects, hand tools are not cast.

By means of thixocasting steel, technical difficulties can be reduced and new options are provided which allow the manufacturing of components with much higher complexity than that using forging. Through near‐net shape production, manufacturing steps and costs can be reduced. Furthermore, steels, which are difficult to forge but nonetheless have high potential for specific applications (such as high strength or corrosion resistant steels), can also be processed.

In cooperation with industrial partners, X39CrMo17 stainless steel size 17 combination spanners were thixocast. Forming dies were designed and optimized by simulation, the hot forming X38CrMoV5 tool steel as well as the molybdenum alloy TZM were selected as the tool alloys. The dies were treated by a plasma nitriding process and subsequently coated with crystalline Al2O3 protective coatings by plasma‐enhanced chemical vapor deposition (PECVD). During the experiments, combination spanners were successfully cast in the semi‐solid state. Cast parts were heat‐treated to enhance the components' toughness, which was subsequently measured by Charpy impact and tensile tests.
Dependence of Accelerated Creep Rate at 580 °C and Room Temperature Yield Stress for Two Creep Resistant Steels
Authors: Vodopivec F. , Vojvodič‐Tuma J. , Jenko M. , Celin R. , Šuštaršič B.
Published: July 2010

Two creep resistant steels, P91 and X20, were tempered for 17520 h at 650 °C or 8760 h at 750 °C to study the growth and redistribution of carbide precipitates in martensite. On specimens annealed for a different time, yield stress at room temperature and accelerated creep rate at 580 °C were determined. With increasing yield stress in the range from 350 to 650 MPa the accelerated creep rate decreased continuously by about 2 orders of magnitude from 8·10−7 s−1 to 5·10−9 s−1. For equal yield stress, the creep rate was slightly lower for the steel P91 than for the steel X20.
Short‐term Creep Behavior of an X 37 Cr Mo V 5‐1 Hot‐work Tool Steel with almost Bainitic and fully Martensitic Microstructures
Authors: Wurmbauer H. , Leitner H. , Panzenböck M. , Scheu C. , Clemens H.
Published: July 2010

In this study two different heat treatments were conducted on an X 37 Cr Mo V 5‐1 hot‐work tool steel, resulting either in a tempered fully martensitic matrix or a matrix almost consisting of tempered bainite. Short‐term creep tests were performed at a high stress level of 800 MPa and at temperatures in the range from 450 °C to 500 °C. Creep specimens consisting of a tempered fully martensitic microstructure exhibited a three times longer creep‐to‐rupture time, than those consisting of a tempered almost bainitic microstructure. Microstructural investigations of creep specimens were performed by transmission electron microscopy. Results of these investigations revealed that due to a lower cooling rate, which is necessary to form bainite, the tempered bainitic microstructure consists of large former bainitic plates, whereas tempered martensite shows fine former martensitic laths. Tempered bainite also exhibits a higher number density of large M3C, M7C3 and MC carbides than tempered martensite. Small M2C carbides appear in both microstructures in the same quantity, however, nanometer‐sized MC carbides could only be found in tempered martensite. Thus poor short‐term creep behavior of the tempered almost bainitic microstructure can be explained by the lesser amount of strengthening relevant precipitates, a smaller size‐effect due to distance of bainitic interfaces as well as lower solid solution hardening.
An Improved Synthesis of Ternary Carbonates: The Examples LiLa(CO3)2 and La(CO3)F
Authors: Glaser Jochen , Meyer H.‐Jürgen
Published: July 2010

The ternary carbonate LiLa(CO3)2, previously obtained under supercritical CO2 pressure conditions was prepared by a new and efficient way of synthesis. A 2:1 molar mixture of Li2(CO3) and LaCl3 reacted in a silica tube at 400 °C. The crystal structure of LiLa(CO3)2 was refined from X‐ray single‐crystal data and can be related with a caesium chloride type arrangement, where Li+ and La3+ ions occupy the cesium positions and (CO3)2– ions occupy all cubic voids. Cerium‐doped samples (LiLa(CO3)2:Ce) exhibit blue luminescence. The mineral bastnäsite was synthesized by the same preparative approach, departing from a 1:1 molar mixture of LaF3 and Li2(CO3) being reacted at 450 °C.
Secondary non‐response due to antibody formation in a child after three injections of botulinum toxin B into the salivary glands
Authors: Berweck Steffen , Schroeder A Sebastian , Lee Seung‐Hee , Bigalke Hans , Heinen Florian
Published: July 2010

Botulinum toxin (BTX) offers a new treatment option to reduce drooling in adults and children. Antibody formation against BTX is known to be one reason for clinical secondary non‐response to this treatment. This is a case report on the development of secondary non‐response to BTX type B (BTX‐B) in a 15‐year‐old male, with bilateral dyskinetic cerebral palsy (Gross Motor Function Classification System Level IV) with additional learning disability* and microcephaly, treated for the indication of drooling. After three successful treatment sessions, the fourth and fifth injections showed no clinical response. This was associated with the presence of antibodies against BTX‐B as determined using the mouse diaphragm assay. Thus, formation of neutralizing antibodies against BTX‐B appears to be an important issue, not only in patients treated for cervical dystonia but also in children treated for drooling. Subsequent injections with an adequate dose of BTX type A (BTX‐A) did not show any clinical response either, although no antibodies to BTX‐A were detected. Besides the unanswered questions of dosing and distribution, a second possible explanation could be that BTX‐B gave rise to non‐neutralizing antibodies that cross‐react with BTX‐A. The resulting immune complexes could be taken up by phagocytes and, thereby, impede clinical response.
Does horseback riding therapy or therapist‐directed hippotherapy rehabilitate children with cerebral palsy?
Authors: Sterba John A
Published: July 2010

Quantitative (not qualitative) studies were sought investigating whether horseback riding used as therapy improves gross motor function in children with cerebral palsy (CP). Eleven published studies on instructor‐directed, recreational horseback riding therapy (HBRT) and licensed‐therapist‐directed hippotherapy were identified, reviewed, and summarized for research design, methodological quality, therapy regimen, internal/external validity, results, and authors’conclusions. Methodological quality was moderate to good for all studies; some studies were limited by small sample size or lack of non‐riding controls. HBRT improved gross motor function in five of six studies (one study was inconclusive); hippotherapy improved gross motor function in all five studies. The studies found that during HBRT and hippotherapy: (1) the three‐dimensional, reciprocal movement of the walking horse produced normalized pelvic movement in the rider, closely resembling pelvic movement during ambulation in individuals without disability; (2) the sensation of smooth, rhythmical movements made by the horse improved co‐contraction, joint stability, and weight shift, as well as postural and equilibrium responses; and (3) that HBRT and hippotherapy improved dynamic postural stabilization, recovery from perturbations, and anticipatory and feedback postural control. The evidence suggests that HBRT and hippotherapy are individually efficacious, and are both medically indicated as therapy for gross motor rehabilitation in children with CP. Recommendations for future research are discussed.
Concurrent goal-based execution of Constraint Handling Rules
Authors: LAM EDMUND S. L. , SULZMANN MARTIN
Published: July 2010

We introduce a systematic, concurrent execution scheme for Constraint Handling Rules (CHR) based on a previously proposed sequential goal-based CHR semantics. We establish strong correspondence results to the abstract CHR semantics, thus guaranteeing that any answer in the concurrent, goal-based CHR semantics is reproducible in the abstract CHR semantics. Our work provides the foundation to obtain efficient, parallel CHR execution schemes.
Heat and salt balances over the New England continental shelf, August 1996 to June 1997
Authors: Lentz S. J. , Shearman R. K. , Plueddemann A. J.
Published: July 2010

Heat and salt balances over the New England shelf are examined using 10 month time series of currents, temperature, and salinity from a four element moored array and surface heat and freshwater fluxes from a meteorological buoy. A principal result is closure of the heat budget to 10 W m−2. The seasonal variation in depth‐average temperature, from 14°C in September to 5°C in March, was primarily due to the seasonal variation in surface heat flux and a heat loss in winter caused by along‐shelf advection of colder water from the northeast. Conductivity sensor drifts precluded closing the salt balance on time scales of months or longer. For time scales of days to weeks, depth‐average temperature and salinity variability were primarily due to advection. Advective heat and salt flux divergences were strongest and most complex in winter, when there were large cross‐shelf temperature and salinity gradients at the site due to the shelf‐slope front that separates cooler, fresher shelf water from warmer, saltier slope water. Onshore flow of warm, salty slope water near the bottom and offshore flow of cooler, fresher shelf water due to persistent eastward (upwelling‐favorable) winds caused a temperature increase of nearly 3°C and a salinity increase of 0.8 in winter. Along‐shelf barotropic tidal currents caused a temperature decrease of 1.5°C and a salinity decrease of 0.7. Wave‐driven Stokes drift caused a temperature increase of 0.5°C and a salinity increase of 0.4 from mid December to January when there were large waves and large near‐surface cross‐shelf temperature and salinity gradients.
Modeling aerosol growth by aqueous chemistry in a nonprecipitating stratiform cloud
Authors: Ovchinnikov Mikhail , Easter Richard C.
Published: July 2010

The modification of sulfate aerosol by the activation, aqueous chemistry, resuspension cycle in a shallow marine stratiform cloud is modeled using a large‐eddy simulation (LES) model and a trajectory ensemble model (TEM). Both dynamical frameworks are coupled with a new microphysics module based on a 2‐D joint size distribution function representing both interstitial and cloud particles. Particle mixing, which is represented in LES but not TEM, leads to slightly broader droplet spectra and 6% lower droplet number on average. TEM simulations with a 1‐D moving‐bin microphysics module, also included in the study, predict far narrower droplet spectra and 15% higher droplet number that are closer to observations except near the cloud boundaries where mixing appears to be important. Despite these differences in simulated droplet spectra, predicted changes in aerosol spectra due to aqueous chemistry are consistent among all three model configurations. The TEM model is used to evaluate assumptions about liquid water partitioning among activated cloud condensation nuclei (CCN). These assumptions are used in large‐scale models to map the bulk aqueous chemistry sulfate production to the changes in the aerosol size distribution. Previously used assumptions, such as droplet mass being independent of CCN size or droplet mass being proportional to CCN mass, do not perform well in the considered case. The aerosol spectra changes from aqueous chemistry using these two assumptions differ markedly from the spectra changes with the explicitly predicted water partitioning and have root‐mean‐squared deviations normalized by the mean (RMSDnorm) of 0.51 and 1.17. These deviations greatly exceed the uncertainties because of the treatment of mixing in the TEM and numerical diffusion in the fixed‐bin representation for which the RMSDnorm is about 0.15. Instead, the explicitly predicted water partitioning suggests that in the considered case the mean droplet mass is proportional to CCN dry size.
Controls on subduction reorganization in the Hellenic margin, eastern Mediterranean
Authors: Capitanio F. A. , Zlotnik S. , Faccenna C.
Published: July 2010

In subduction modeling, interactions between the down‐going slab and neighboring plates are often neglected. Here, we have modeled the interactions between a subducting and an upper plate and show that, in such a system, subducting plate advance towards the stationary margin accommodates convergence. When interactions with the lower mantle are included in this system, deeper penetration of the slab allows transient increases in subduction rates and weakening in the upper plate. However this does not last long enough to mobilize the trench away from the upper plate. The constraints imposed by the convergence of major plates are more effective in reorganizing the tectonic style, by hampering, or even locking, the subducting plate motions resulting in sustained rollback and back‐arc opening over large time periods. A comparison with the tectonics of the Hellenic margin suggests that such boundary conditions might be the key to the reorganization of plate motions in this area.
Genome-scale dynamic modeling of the competition between Rhodoferax and Geobacter in anoxic subsurface environments
Authors: Zhuang Kai , Izallalen Mounir , Mouser Paula , Richter Hanno , Risso Carla , Mahadevan Radhakrishnan , Lovley Derek R
Published: July 2010

The advent of rapid complete genome sequencing, and the potential to capture this information in genome-scale metabolic models, provide the possibility of comprehensively modeling microbial community interactions. For example, Rhodoferax and Geobacter species are acetate-oxidizing Fe(III)-reducers that compete in anoxic subsurface environments and this competition may have an influence on the in situ bioremediation of uranium-contaminated groundwater. Therefore, genome-scale models of Geobacter sulfurreducens and Rhodoferax ferrireducens were used to evaluate how Geobacter and Rhodoferax species might compete under diverse conditions found in a uranium-contaminated aquifer in Rifle, CO. The model predicted that at the low rates of acetate flux expected under natural conditions at the site, Rhodoferax will outcompete Geobacter as long as sufficient ammonium is available. The model also predicted that when high concentrations of acetate are added during in situ bioremediation, Geobacter species would predominate, consistent with field-scale observations. This can be attributed to the higher expected growth yields of Rhodoferax and the ability of Geobacter to fix nitrogen. The modeling predicted relative proportions of Geobacter and Rhodoferax in geochemically distinct zones of the Rifle site that were comparable to those that were previously documented with molecular techniques. The model also predicted that under nitrogen fixation, higher carbon and electron fluxes would be diverted toward respiration rather than biomass formation in Geobacter, providing a potential explanation for enhanced in situ U(VI) reduction in low-ammonium zones. These results show that genome-scale modeling can be a useful tool for predicting microbial interactions in subsurface environments and shows promise for designing bioremediation strategies.
Staurosporine, K‐252a, and K‐252b Stabilize Calcium Homeostasis and Promote Survival of CNS Neurons in the Absence of Glucose
Authors: Cheng Bin , Barger Steven W. , Mattson Mark P.
Published: July 2010

Abstract: Staurosporine, K‐252a, and the 9‐carboxylic related compound K‐2525 are low‐molecular‐weight alkaloids from microbial origin that at high concentrations are kinase inhibitors and can antagonize the effects of neuronal growth factors. Paradoxically, we have found that very low concentrations of these agents (10 fM‐10 nM) prolong the survival of hippocampal, septal, and cortical neurons deprived of glucose. These agents did not prevent the depletion of ATP caused by glucose deprivation. The large elevation of intracellular calcium levels that normally mediates glucose deprivation‐induced damage was attenuated by Staurosporine, K‐252a, and K‐252b. Western blot analysis using antiphosphotyrosine antibody showed that Staurosporine and the K‐252 compounds (10–100 pM) stimulated tyrosine phosphorylation of several different proteins. The tyrosine kinase inhibitor genistein significantly reduced the protective effect of Staurosporine and the K‐252 compounds, indicating that tyrosine phosphorylation was required for neuroprotection by these compounds. Taken together, the data demonstrate that low concentrations of Staurosporine and the K‐252 compounds can stabilize calcium homeostasis, possibly by a mechanism involving activation of receptor tyrosine kinase transduction pathways.
Effect of the Non‐NMDA Receptor Antagonist GYKI 52466 on the Microdialysate and Tissue Concentrations of Amino Acids Following Transient Forebrain Ischaemia
Authors: Arvin B. , Lekieffre D. , Graham J. L. , Moncada C. , Chapman A. G. , Meldrum B. S.
Published: July 2010

Abstract: The effect of the non‐N‐methyl‐D‐aspartate (non‐NMDA) receptor antagonist 1‐(4‐aminophenyl)‐4‐methyl‐7,8‐methylenedioxy‐5H‐2,3‐benzodiazepine hydrochloride (GYKI 52466) on ischaemia‐induced changes in the microdialysate and tissue concentrations of glutamate, aspartate, and γ‐aminobutyric acid (GABA) was studied in rats. Twenty minutes of four‐vessel occlusion resulted in a transient increase in microdialysate levels of glutamate, aspartate, and GABA in striatum, cortex, and hippocampus. Administration of GYKI 52466 (10 mg/kg bolus + 10 mg/kg/60 min intravenously starting 20 min before onset of ischaemia) inhibited ischaemia‐induced increases in microdialysate glutamate and GABA in striatum without affecting the increases in hippocampus or cortex. Twenty minutes of four‐vessel occlusion resulted in immediate small decreases and larger delayed (72 h) decreases in tissue levels of glutamate and aspartate. Transient increases in tissue levels of GABA were shown in all three structures at the end of the ischaemic period. At 72 h, after the ischaemic period, significantly reduced GABA levels were observed in striatum and hippocampus. GYKI 52466, given under identical conditions as above, augmented the ischaemia‐induced decrease in striatal tissue levels of glutamate and aspartate, without significantly affecting the decreases in hippocampus and cortex. Twenty minutes of ischaemia resulted in a large increase in microdialysate dopamine in striatum. GYKI 52466 failed to inhibit this increase. Kainic acid (500 μM infused through the probe for 20 min) caused increases in microdialysate glutamate and aspartate in the striatum. GYKI 52466 (10 mg/ kg bolus + 10 mg/kg/60 min) completely inhibited the kainic acid‐induced glutamate release. In conclusion, the action of the non‐NMDA antagonist, GYKI 52466, in the striatum is different from that in the cortex and hippocampus. The inhibition by GYKI 52466 of ischaemia‐induced and kainate‐induced increases in microdialysate glutamate concentration in the striatum may be related to the neuroprotection provided by GYKI 52466 in this region.
Isoprenylated Proteins in Myelin
Authors: Sepp‐Lorenzino Laura , Coleman Peter S. , Larocca Jorge N.
Published: July 2010

Abstract: Incubation of rat brainstem slices with [3H]‐ mevalonate ([3H]MVA) in the presence of lovastatin resulted in the incorporation of label into three groups of myelin‐associated proteins with molecular masses of 47, 21–27, and 8 kDa, as revealed on sodium dodecyl sulfate‐ polyacrylamide rod gel electrophoresis. Although the gel patterns of [3H]MVA‐derived prenylated proteins were similar, the relative level of 3H incorporated into each protein species differed between myelin and the brainstem homogenate. Immunoprecipitation studies identified the 47‐kDa prenylated protein as a 2′‐3′‐cyclic nucleotide phospho‐ diesterase, whereas the 8‐kDa protein proved to be the γ subunit of membrane‐associated guanine nucleotide regulatory protein. The 3H‐labeled 21–27‐kDa group in myelin corresponds to the molecular mass of the extensive Ras‐ like family of monomeric GTP‐binding proteins known to be prenylated in other tissues. Increase in lovastatin concentration resulted in reduced levels of [3H]MVA‐labeled species in myelin and concomitantly increased levels in the cytosol. A cold MVA chase restored to normality the appearance of [3H]MVA‐labeled proteins in myelin. Furthermore, a high lovastatin concentration in the brainstem slice incubation mixture altered the appearance of newly synthesized nonprenylated myelin proteins, including proteolipid protein and the 17‐kDa subspecies of myelin basic protein. Because other myelin proteins were unaffected by the high lovastatin concentration, restricting the availability of MVA in myelin‐forming cells may selectively alter processes required for myelinogenesis. Although the molecular basis for the” different MVA requirements in myelin‐ forming cells remains undefined, it may involve an alteration in the biological activity of certain proteins that require prenylation to be functionally active, and that are responsible for promoting insertion of specific proteins into the myelin membrane.
Fixed Versus Removable Microdialysis Probes for In Vivo Neurochemical Analysis: Implications for Behavioral Studies
Authors: Fumero Blas , Guadalupe Teresa , Valladares Francisco , Mora Francisco , O'Neill Robert D. , Mas Manuel , Gonzalez‐Mora Jose Luis
Published: July 2010

Abstract: The levels of several neurochemicals, i.e., uric acid (UA), dopamine (DA), dihydroxyphenylacetic acid, and 5‐hydroxyindoleacetic acid, collected daily from the rat striatum with either fixed or removable microdialysis probes for 7 days after surgery were compared. The implantation of the fixed cannula was followed by a 10‐fold increase in the UA content in the dialysates collected from the first day after surgery onward and by a steady decrease in dihydroxyphenylacetic acid levels, whereas those of DA remained fairly stable. With the removable cannula system, only a smaller, transient increase in UA during the first 3 days after surgery was observed, with no change in DA or monoamine metabolites. The glial reaction around the cannula tracks was assessed by both quantitative histological techniques and measuring the glutamine levels in the dialysates collected at the time of surgery and 7 days later. Both the glial cell number and nuclear size, as well as the glutamine outflow, were considerably larger in the animals implanted with the fixed probes. It is, therefore, likely that the UA levels in the dialysate reflect the glial reaction to the probe. The suitability of the removable probe system for behavioral experiments involving repeated microdialysis sampling was illustrated in an experiment showing that the DA release in the nucleus accumbens of male rats assessed daily at postsurgery days 5–10 was virtually identical in three alternating sessions of sexual behavior as was the smaller release of this neurotransmitter detected during intervening nonsexual social interactions.
Amphetamine Promotes Neostriatal Ascorbate Release via a Nigro‐Thalamo‐Cortico‐Neostriatal Loop
Authors: Pierce R. Christopher , Clemens Amy J. , Grabner Chad P. , Rebec George V.
Published: July 2010

Abstract: In the neostriatum, amphetamine and other dopamine agonists elevate the extracellular level of ascorbate, which is known to modulate neostriatal function. Although both D1 and D2 receptors have been linked to neostriatal ascorbate release, ample evidence suggests it is controlled by areas outside the neostriatum. The present series of experiments used selective lesions and intracerebral drug infusions to probe the involvement of the ventromedial thalamus and substantia nigra pars reticulata. Our results implicate both of these sites in amphetamine‐induced increases in the release of neostriatal ascorbate. Thus, whereas unilateral electrolytic lesions of the substantia nigra pars reticulata completely abolished the ability of systemic amphetamine (2.5 mg/kg) to increase extracellular ascorbate in ipsilateral neostriatum, intranigral infusions of this drug (10 and 30 µg/µl) elevated neostriatal ascorbate release. This infusion effect, moreover, was blocked by electrolytic lesions of the ipsilateral ventromedial thalamus, which receives input from the substantia nigra pars reticulata and projects to the cerebral cortex. These results, combined with previous evidence implicating cortical projections to neostriatum as the source of extracellular ascorbate, suggest that neostriatal ascorbate release is regulated, at least in part, by a nigro‐thalamo‐cortico‐neostriatal pathway.
Decreased Catalase Activity but Unchanged Superoxide Dismutase Activity in Brains of Patients with Dementia of Alzheimer Type
Authors: Gsell Wieland , Conrad Rudolf , Hickethier Majida , Sofic Emin , Frölich Lutz , Wichart Ildiko , Jellinger Kurt , Moll Gunther , Ransmayr Gerhard , Beckmann Helmut , Riederer Peter
Published: July 2010

Abstract: “Oxidative stress” may be of significance in the etiopathogenesis of dementia of Alzheimer type (DAT). Therefore, we measured activities of the enzymes superoxide dismutase (SOD) and catalase (CAT), which detoxicate reactive oxygen species. Enzyme activities were measured postmortem in basal ganglia, cortical, and limbic brain regions of patients with DAT and age‐matched controls. SOD activity increased with age in basal nucleus of Meynert. However, there was no significant difference in SOD activity between DAT and controls. CAT activity was independent of age and postmortem time. There were significant reductions in CAT activity in parietotemporal cortex, basal ganglia, and amygdala in DAT compared with controls (p < 0.05 to 0.01). Our findings are in line with the assumption that reactive oxygen species could contribute to the pathogenesis of DAT. Absence of these changes in basal nucleus of Meynert might reflect retrograde degeneration of cholinergic fibers.
Participation of Tubulin in the Stimulatory Regulation of Adenylyl Cyclase in Rat Cerebral Cortex Membranes
Authors: Hatta Shinichi , Ozawa Hiroki , Saito Toshikazu , Ohshika Hideyo
Published: July 2010

Abstract: This study examined effects of tubulin on the activation of adenylyl cyclase in rat cerebral cortex membranes. Tubulin, prepared from rat brain by polymerization with the hydrolysis‐resistant GTP analogue 5′‐guanylylimidodiphosphate (GppNHp) caused significant activation of the enzyme by ∼156% under conditions in which stimulation rather than inhibition of the enzyme was favored. Tubulin‐GppNHp activated isoproterenol‐sensitive adenylyl cyclase, potentiated forskolin‐stimulated activity of the enzyme, and reduced agonist binding affinity for β‐adrenergic receptors. When tubulin, polymerized with the hydrolysis‐resistant photoaffinity GTP analogue [32P]P3(4‐azidoanilido)‐P1‐5′‐GTP ([32P]AAGTP), was incubated with cerebral cortex membranes, AAGTP was transferred from tubulin to Gsα as well as Giα. These results suggest that, in rat cerebral cortex membranes, the tubulin dimer participates in the stimulatory regulation of adenylyl cyclase by transferring guanine nucleotide to Gsα, as well as affecting the Gi‐mediated inhibitory pathway.
The Mammalian Pineal Expresses the Cone but Not the Rod Cyclic GMP Phosphodiesterase
Authors: Carcamo B. , Hurwitz M. Y. , Craft C. M. , Hurwitz R. L.
Published: July 2010

Abstract: To determine the presence of cone or rod cyclic GMP phosphodiesterase (EC 3.1.4.17) in the mammalian pineal, extracts from adult rat and bovine pineals were injected onto a Mono Q anion‐exchange HPLC column and eluted with an NaCl linear gradient. Fractions were immunoadsorbed with monoclonal antibodies specific to rod and cone phosphodiesterases (ROS‐1) and to calmodulin‐phosphodiesterase complexes (ACC). Profiles were assayed with 10 µmol/L [3H]cyclic GMP in the presence of calcium‐calmodulin, histone, or trypsin. Rat and bovine pineals displayed a single peak of activity recognized by ROS‐1, which corresponded to the activity of the cone but, not to the rod in bovine retina. ROS‐1 immunoadsorbed ∼80% of the activity in the 60‐day‐old rat pineal but only 26% of the activity in bovine pineal. ACC immunoadsorbed the remaining activity in both species. Western blot analysis of rat pineal extracts revealed three polypeptides of ∼87, 15, and 10 kDa when probed with a rod/cone phosphodiesterase‐specific antiserum. The specific activity of the cone‐like phosphodiesterase in 10‐day‐old rat pineals was twice that of this isozyme in the bovine retina and 150 times that in the bovine pineal. The specific activity of phosphodiesterase in rat pineals decreased with age. We conclude that an enzyme with biochemical and antigenic characteristics similar to cone, but distinct from rod phosphodiesterase, is present in bovine and rat pineals.
d‐Fenfluramine Increases Striatal Extracellular Dopamine In Vivo Independently of Serotonergic Terminals or Dopamine Uptake Sites
Authors: De Deurwaerdère Philippe , Bonhomme Norbert , Le Moal Michel , Spampinato Umberto
Published: July 2010

Abstract: The effect of various doses of the serotonin (5‐HT) release‐inducing agent d‐fenfluramine (d‐fenf) on extracellular dopamine (DA), 3,4‐dihydroxyphenylacetic acid (DOPAC), and 5‐hydroxyindoleacetic acid (5‐HIAA) was studied in vivo in the striatum of halothane‐anesthetized rats, following systemic and local administration. At 5 and 10 but not 2.5 mg/kg, d‐fenf administered intraperitoneally significantly increased DA extracellular concentration and reduced DOPAC outflow. A concentration‐dependent enhancement of DA dialysate content was also found following intrastriatal application (5, 10, 25, and 50 µM). The bilateral administration of 5,7‐dihydroxytryptamine into the dorsal raphe nucleus, which markedly depleted 5‐HT in the striatum, did not modify the effect on extracellular DA concentration of 25 µM d‐fenf locally applied into the striatum. The enhancement of extracellular DA level induced by 25 µM d‐fenf was slightly but significantly reduced by the local application of 25 µM citalopgram. The blockade of DA uptake sites by nomifensine (0.1, 0.3, and 1 µM) did not modify significantly the effect of d‐fenf. The rise of DA outflow induced by 25 µM d‐fenf was strongly reduced in the presence of 1 µM tetrodotoxin (TTX) or by the removal of Ca2+ from the perfusion medium. The results obtained show that d‐fenf increases the striatal extracellular DA concentration by a Ca2+‐dependent and TTX‐sensitive mechanism that is independent of striatal 5‐HT itself or DA uptake sites.
D2 Receptor Antagonists Do Not Modify Guanine Nucleotide‐Sensitive Interactions Between Dopamine and D1 Dopamine Receptors Under In Vitro Conditions
Authors: Farrell C. B. , Lawlor M. , Dunne A. , O'Boyle K. M.
Published: July 2010

Abstract: This study investigated possible D1/D2 interactions in rat and bovine striatal tissue by examining the effects of D2 antagonists on the action of dopamine at D1 dopamine receptors. In addition, the extent to which D2 antagonists may induce an agonist low‐affinity state of the D1 receptor was evaluated in comparison with the effects of the guanine nucleotide analogue 5′‐guanylylimidodiphosphate [Gpp(NH)p]. In saturation experiments dopamine caused a dose‐dependent decrease in rat striatal and bovine caudate D1 receptor density. This effect of dopamine, which has been shown to be sensitive to Gpp(NH)p, was not altered by pretreatment with either of the selective D2 antagonists eticlopride (200 nM) or domperidone (200 nM). Results from displacement experiments show that the affinity of dopamine for D1 receptors and the proportion of receptors in an agonist high‐affinity state, are reduced by Gpp(NH)p (100 µM) but not by eticlopride. A molar excess of dopamine (100 µM) promotes the dissociation of (±)‐8‐chloro‐2,3,4,5‐tetrahydro‐3‐methyl‐5‐phenyl‐1H‐3‐benzazepine‐7‐ol ([3H]SCH 23390) from rat striatal D1 receptors at a rate that is significantly slower than when dissociation is initiated using 1 µM piflutixol. After pretreatment with Gpp(NH)p, [3H]SCH 23390 dissociation induced by dopamine occurred at an even slower rate. Pretreatment with eticlopride had no effect on the dopamine‐induced rate of [3H]SCH 23390 dissociation. These results indicate that all experimental approaches detected dopamine effects at D1 receptors that are Gpp(NH)p sensitive and D2 antagonist insensitive and provide no evidence to support a D1/D2 link operating at the receptor level.
Serotonergic Regulation of Acetylcholine Release in Rat Frontal Cortex
Authors: Hirano Hitoshi , Day Jamie , Fibiger Hans C.
Published: July 2010

Abstract: The extent to which serotonin regulates the activity of cortically projecting cholinergic neurons was studied using in vivo microdialysis to monitor interstitial concentrations of acetylcholine in the frontal cortex of freely moving rats. Systemic administration of the serotonin release‐inducing agent fenfluramine (3 or 10 mg/kg, i.p.) increased acetylcholine release by 110–130%. The fenfluramine‐induced increase in acetylcholine release was significantly attenuated by pretreatment with the selective serotonin uptake inhibitor fluoxetine (10 mg/kg, i.p.). Pretreatment with the selective dopamine D1 receptor antagonist SCH‐23390 (0.3 mg/kg, s.c.) failed to prevent the fenfluramine‐induced increase in acetylcholine release. In contrast, the serotonin 5‐HT2A receptor antagonist ketanserin (5 mg/kg, i.p.) blocked fenfluramine‐induced increases in acetylcholine release. In contrast to previous studies that have concluded that serotonin has inhibitory actions on cortical acetylcholine release, the present results indicate that fenfluramine increases cortical acetylcholine release in vivo by its ability to enhance serotonin transmission and that serotonin produces these effects at least in part via actions at serotonin 5‐HT2A receptors.
Concentrations of 3,4‐Dihydroxyphenylalanine and Catecholamines and Metabolites in Brain in an Anhepatic Model of Hepatic Encephalopathy
Authors: Hadesman Robert , Wiesner Russell H. , Go V. L. W. , Tyce Gertrude M.
Published: July 2010

Abstract: Alterations in the catecholaminergic neurotransmitter systems have been shown to occur in hepatic failure and may contribute to development of hepatic encephalopathy. In the present study we used the rat after complete hepatectomy as a model for study of changes that occur in brain in acute liver failure. We attempted to identify processes in the synthesis, storage, and metabolism of catecholamine neurotransmitters that might be changed during liver failure by measuring levels of, together with those of norepinephrine and dopamine, the precursor (3,4‐dihydroxyphenylalanine) and the neuronal metabolites of dopamine and norepinephrine (3,4‐dihydroxyphenylacetic acid and 3,4‐dihydroxyphenylglycol, respectively) in different regions of brains of control rats and of rats after hepatectomy. We found that in most brain regions of hepatectomized rats there were increases in the concentration of 3,4‐dihydroxyphenylalanine or of dopamine but decreases in the concentrations of norepinephrine or of 3,4‐dihydroxyphenylglycol. The particulate/supernatant ratios of catecholamines are indices of retention of neurotransmitters in storage sites. These ratios were not different in brain regions between control rats and hepatectomized rats, suggesting that vesicular retention of catecholamines in brain was not impaired after hepatectomy. The data suggest that inhibition of dopamine‐β‐hydroxylase might be a characteristic of hepatic failure.
Comment on “Energy transfer in nanowire solar cells with photon-harvesting shells” [J. Appl. Phys. 105, 124509 (2009)]
Authors: Markvart T. , Danos L. , Greef R.
Published: July 2010

In a recent article, Peters et al. [J. Appl. Phys. 105, 124509 (2009)] claim to have observed photosensitization of crystalline silicon by energy transfer from an optically absorbing thin polymer film. We show that this claim is not justified. Their experimental design is not adequate to establish enhanced photoexcitation of silicon; moreover, the theoretical arguments in their interpretation do not stand up to scrutiny.
Multiscale chemical reactions in reactive powder metal mixtures during shock compression
Authors: Reding D. J.
Published: July 2010

A mesoscale reaction (MSR) model is proposed as part of a multiscale numerical modeling approach to study reactive powder metal mixtures. A discrete particle simulation (DPS) incorporates details of phase morphology and arrangement which are an integral part of designing this class of materials. The DPS provides the spatial distribution for the contact sites or locations in which reactant granules come into contact. Temperature and reactant contact surfaces, estimated from DPS results, are used to initialize the MSR model. A heterogeneous granular-level reaction model is incorporated into the MSR model to describe the chemical reactions between reactant granules. Ensemble averages from the MSR model describe the bulk mixture reaction rate in the macroscale continuum model. The proposed approach is demonstrated for a powder mixture containing Ni+Al+voids. Shock-induced reactions are simulated and compared to experiments.
Structure and spectroscopy of ground and excited states of LiYb
Authors: Zhang P. , Sadeghpour H. R. , Dalgarno A.
Published: July 2010

Multireference configuration interaction and coupled cluster calculations have been carried out to determine the potential energy curves for the ground and low-lying excited states of the LiYb molecule. The scalar relativistic effects have been included by means of the Douglas–Kroll Hamiltonian and effective core potential and the spin-orbit couplings have been evaluated by the full microscopic Breit–Pauli operator. The LiYb permanent dipole moment, static dipole polarizability, and Franck–Condon factors have been determined. Perturbations of the vibrational spectrum due to nonadiabatic interactions are discussed.
Stand alone experimental setup for dc transport measurements
Authors: Suslov A. V.
Published: July 2010

Described is a system consisted of Keithley’s current source Model 6221 and nanovoltmeter Model 2182A pairs. That pair was developed by Keithley for precise measurements of a sample’s one electrical parameter by the dc current-reversal transport technique. Nonstandard synchronization method employed in the presented setup allows assembling several pairs together for low level electrical measurements of a sample’s several parameters associated with the same current, thus expanding the applications of these devices. The equipment was tested by simultaneous measurements of such two parameters as transverse magnetoresistance and Hall voltage on the following materials: Si/SiGe, Ge:Mn; HgTe/HgCdTe, and InMnSb.
Effect of edge smoothening on the extinction spectra of metal nanoparticles
Authors: Jayabalan J. , Singh Asha , Chari Rama
Published: July 2010

To calculate the extinction spectrum of a metal nanoparticle, it is common to use a regular shape which is close to the experimental one. We show that, to model a real metal particle, it is essential to remove sharp corners and tips and smoothen the bounding surface. An efficient and simple method to smoothen the tips and corners of the model shape of the particle is presented. The extinction calculated using smoothed particles predicts more accurately the extinction spectrum of as grown particles as well as the changes in the extinction spectrum during melting and reshaping of the particle.
Comparisons of kinetic ablation models for the capillary discharge
Authors: Li Rui , Li Xingwen , Jia Shenli , Murphy Anthony B.
Published: July 2010

The properties of kinetic ablation models are considered in this paper. The widely used kinetic ablation model (model-K) only considers monatomic vapor. A revised model (model-Z) was introduced by taking into account the polyatomic vapor’s internal degrees of freedom, as well as the temperature dependence of the average particle mass. In this work, both temperature and pressure dependence of average particle mass and the specific heat ratio γ are taken into account, producing an improved version of model-Z (denoted model-Z∗). Ablation data calculated by model-K and model-Z∗ for two typical capillary materials are presented. Compared to model-K, model-Z∗ predicts an increased ablation rate at lower plasma temperature and higher plasma density, and a decreased rate for the opposite conditions. Finally, based on the plasma parameters in a typical discharge cycle, all three models are used to calculate the time-dependent ablation rate and the integrated ablated mass. It is found that the main difference between their results arises because of the different average particle masses near the wall surface, and model-Z∗ is the most accurate for the discharge cycle considered. Further, it is found that the ablation parameters are highly sensitive to the pressure, in particular, through the pressure dependence of average particle mass.
Bending manipulation induced sp2–sp3 bond transition in carbon nanotubes
Authors: Tang Chun , Guo Wanlin , Chen Changfeng
Published: July 2010

Introducing sp3 bonds in carbon nanotubes can significantly modify their electronic properties but need high pressure at room temperature. Here we show by molecular dynamics simulations that sp2 to sp3 bond transition can be realized through bending manipulation at the buckling location, resembling that of nanoindented carbon nanostructures but with more convenient operation technique. The capability of sp3 bond formation is sensitive to the thickness and diameter of the carbon nanotubes. This bending induced sp3 structures can serve as tunneling junction for electrons, thus bending manipulation could be a route to tailoring nanocircuits.
Efficient unidirectional generation of surface plasmon polaritons with asymmetric single-nanoslit
Authors: Chen Jianjun , Li Zhi , Yue Song , Gong Qihuang
Published: July 2010

An asymmetric single-nanoslit composed of a conventional nanoslit with a nanogroove next to it in a metallic film is proposed to generate unidirectional surface plasmon polaritons (SPPs) efficiently with back-side illumination. Numerical simulations show that due to the different interference processes of SPPs to opposite directions, efficient unidirectional SPP generation can be achieved. Experimentally, an extinction ratio of about 30:1 for SPPs to opposite directions and a generation efficiency of about 1.8 times that of the symmetrical case are demonstrated at wavelength of 830 nm with the lateral dimension of the asymmetric single-nanoslit of only 370 nm.
Temperature dependence of the magnetoelectric effect in Pb(Zr0.2Ti0.8)O3/La0.8Sr0.2MnO3 multiferroic heterostructures
Authors: Vaz C. A. F. , Segal Y. , Hoffman J. , Grober R. D. , Walker F. J. , Ahn C. H.
Published: July 2010

The magnetoelectric response of Pb(Zr0.2Ti0.8)O3/La0.8Sr0.2MnO3 (PZT/LSMO) artificial multiferroic heterostructures as a function of temperature, electric, and magnetic field, shows that the largest magnetoelectric coupling is attained at temperatures near the magnetic critical point of LSMO, at ∼180 K (−13.5 Oe cm kV−1). The magnetoelectric coupling displays a strong temperature dependence, changing sign at 150 K and saturating to positive values below ∼100 K (+6 Oe cm kV−1). The magnetoelectric curve switches hysteretically between two states in response to the ferroelectric switching. The peak in the magnetoelectric response coincides with the observation of on/off switching of magnetism in LSMO near the critical region, where the sensitivity to electric field is largest, making it a promising approach for device applications.
On the origin of efficient electron injection at phosphonate-functionalized polyfluorene/aluminum interface in efficient polymer light-emitting diodes
Authors: Zhang Baohua , Qin Chuanjiang , Niu Xiaodi , Xie Zhiyuan , Cheng Yanxiang , Wang Lixiang , Li Xinglin
Published: July 2010

Ultraviolet and x-ray photoelectron spectroscopy are used to explore the underlying mechanism of efficient electron injection at phosphonate-functionalized polyfluorene (PF-EP)/Al interface in polymer light-emitting diodes (PLEDs). It is proposed that both the favorable interfacial dipoles of phosphonate groups and intense coordination interaction between the phosphonate groups and Al at PF-EP/Al interface are responsible for the efficient electron injection. As a result, the PLEDs with PF-EP/Al cathode demonstrate superior performance compared to the PLEDs with Ba or Ca cathode due to efficient electron injection and suppressed exciton-quenching at cathode interface.