bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ghrelin test for the assessment of GH status in successfully treated patients with acromegaly
Authors: Pekic S , Doknic M , Miljic D , Joksimovic M , Glodic J , Djurovic M , Dieguez C , Casanueva F , Popovic V 
Published: April 2006

Objective: Posttreatment assessment of disease activity and definition of cure of acromegaly, using measurement of GH secretion, remains problematic. Furthermore, with our efforts to achieve tight biochemical control of the disease it is foreseeable that a proportion of patients may be rendered GH deficient, thus requiring testing for GH deficiency. The aim of our study was to evaluate residual GH secretion in cured patients with acromegaly.
Design and methods: At baseline, circulating GH, IGF-I, IGFBP-3, leptin and lipid (cholesterol and tri-glycerides) levels were measured in 33 acromegalic patients nine years after treatment with surgery of whom 6 were additionally irradiated. Two tests were performed: the GH suppression test - oral glucose tolerance test (OGTT) and the GH provocation test - ghrelin test (1 μg/kg i.v. bolus) and the results were compared with 11 age- and sex-matched control subjects.
Results: According to the consensus criteria (normal IGF-I levels and post-OGTT GH nadir <1 μg/l), 21 treated acromegalic patients were cured, 6 had discordant IGF-I and GH nadir values during OGTT, while 6 had persistent acromegaly. After the GH provocative test with ghrelin (cut-off for severe GH deficiency is GH <3 μg/l), we detected 9 severely GH deficient patients (GHD) among 21 cured acromegalic patients. Mean GH peak (±s.e.m.) response to the ghrelin test in GHD acromegalics was significantly lower compared with acromegalics with sufficient GH secretory capacity and control subjects (1.2 ± 0.2 μg/l vs 20.1 ± 2.4 μg/l vs 31.1 ± 2.5 μg/l respectively, P<0.0001). Mean IGF-I and IGFBP-3 levels were not different between GHD and GH-sufficient cured acromegalics. Leptin levels and body mass index (BMI) were significantly higher in GHD male acromegalics compared with GH-sufficient male acromegalics. GHD female acromegalics tended to have higher BMIs while leptin levels were not different.
Conclusions: The assessment of residual GH secretory capacity by the GH provocation test is necessary in the long-term follow-up of successfully treated acromegalics since a large proportion of these patients are rendered GH deficient.
Neutralization Potential Determination of Siderite (FeCO3) Using Selected Oxidants
Authors: Haney E. B. , Haney R. L. , Hossner L. R. , White G. N. 
Published: April 2006

ABSTRACTSiderite (FeCO3) is commonly found in coal overburden and, when present, can cause interference in the determination of neutralization potential (NP). Under acidic testing conditions, FeCO3 reacts to neutralize acid, which contributes to the NP. However, continued weathering of FeCO3 (oxidation of Fe2+ and hydrolysis of Fe3+) produces a neutral to slightly acidic solution. The effects of hydrogen peroxide (H2O2), potassium permanganate (KMnO4), and O2 on the laboratory measurement of NP of siderite samples taken from overburden were examined. All oxidation treatments lowered the NP values of the siderite samples as compared with the standard USEPA method. However, oxidation with H2O2 produced variable results depending on the amount of H2O2 added. Neutralization potential values obtained after oxidation treatments were highly correlated with Mn concentration. Reaction products (i.e., 2‐line ferrihydrite) of siderite samples with H2O2 and KMnO4 were not representative of natural siderite weathering. Oxidation with O2 produced the lowest NP values for siderite samples. The reaction products produced by oxidation with O2 most closely represent those intermediate products formed when siderite is exposed to atmospheric weathering conditions. Oxidation with O2 also proved to be the most reproducible method for accurately assessing NP when siderite is present in overburden samples.
Aerating Grassland before Manure Application Reduces Runoff Nutrient Loads in a High Rainfall Environment
Authors: van Vliet L. J. P. , Bittman S. , Derksen G. , Kowalenko C. G. 
Published: April 2006

ABSTRACTThe effect of mechanically aerating grassland before liquid manure application in the fall on surface runoff and transport of nutrients and solids was studied in a high rainfall area. The two treatments were control and aeration, the latter receiving one pass with an aerator perpendicular to the slope before fall application of liquid manure (dairy in Years 1–3 and swine in Year 4). Treatments were randomly assigned on 3 to 5% sloping land with a silt loam surface soil (Aquic Dystroxerept) planted in orchardgrass (Dactylis glomerata L.). Runoff from natural rainfall events was sampled for nutrient and solids analysis. Aeration significantly reduced runoff and loads of suspended solids, total Kjeldahl N (TKN), and dissolved reactive P in all years. Annual runoff amounts were reduced by 47 to 81%, suspended and volatile solid loads by 48 to 69% and 42 to 83%, respectively, TKN loads by 56 to 81%, and total P (TP) loads by 25 to 75%. Loads of the soluble nutrient NH4–N, dissolved reactive P, and K were reduced by 41 to 83%. The first three runoff events after manure application accounted for approximately one‐third of the annual total runoff and solid and nutrient loads when averaged across treatments, with loads of TKN, K, and NH4–N totaling 4.4, 3.3, and 1.9 kg ha−1, respectively. Aeration slightly increased downward movement of NO3–N, but not other nutrients in the soil. Thus mechanical aeration can be an effective tool for reducing runoff and loads of solids and nutrients after surface application of liquid manure on sloping grassland.
Reducing Phosphorus Runoff from Dairy Farms
Authors: Bosch Darrell J. , Wolfe Mary Leigh , Knowlton Katharine F. 
Published: April 2006

ABSTRACTPhosphorus (P) runoff from manure can lead to eutrophication of surface water and algae growth. This study evaluates the impacts of alternative P reduction practices on dairy farm net returns and on potential P runoff. The P control practices include dairy herd nutrient management, crop nutrient management, and runoff and erosion control. Four farms representative of dairies in the Virginia Shenandoah Valley are simulated including dairies with and without supplementary broiler enterprises and with average and below average land area. A mathematical programming model was developed to predict farm production and net returns and the GLEAMS model was used to predict potential P runoff. The farms are evaluated under four scenarios: Scenario 1, no constraint on P runoff with access to crop nutrient, runoff and erosion control strategies but no access to dairy herd nutrient control strategies; Scenario 2, no constraint on P runoff with access to all crop and dairy herd nutrient control strategies; Scenario 3, constraint on P runoff with access to crop nutrient, runoff and erosion control strategies but no access to dairy herd nutrient control strategies; and Scenario 4, constraint on P runoff with access to all crop and dairy herd nutrient control strategies. Under Scenario 2, the herd nutrient control strategies increase milk output per cow and net returns on both farms and reduce P content of manure and P runoff. Under Scenario 3, limiting P runoff reduces farm returns by 1 and 3% on the average and small farms, respectively. Under Scenario 4, the P runoff constraint is less costly, reducing returns by less than 1% on both farms. Animal nutrient control strategies should be an important part of pollution control policies and programs for livestock intensive watersheds.
LIGHT (TNFSF14), a novel mediator of bone resorption, is elevated in rheumatoid arthritis
Authors: Edwards J. R. , Sun S. G. , Locklin R. , Shipman C. M. , Adamopoulos I. E. , Athanasou N. A. , Sabokbar A. 
Published: April 2006

AbstractObjectiveHuman osteoclast formation from mononuclear phagocyte precursors involves interactions between tumor necrosis factor (TNF) ligand superfamily members and their receptors. LIGHT is a transmembrane protein expressed and shed from the surface of activated T cells. Since activated T cells have been implicated in osteoclastogenesis in rheumatoid arthritis (RA), this study sought to determine whether LIGHT can regulate RANKL/cytokine‐induced osteoclast formation, to identify the mechanism by which LIGHT influences osteoclastogenesis, and to investigate the presence of LIGHT in the serum of RA patients.MethodsThe effect of LIGHT on human and murine osteoclast formation was assessed in the presence and absence of neutralizing reagents to known osteoclastogenic factors. Serum levels of LIGHT in RA patients were measured by enzyme‐linked immunosorbent assay.ResultsIn the presence and absence of RANKL, LIGHT induced osteoclast formation from both human peripheral blood mononuclear cells and murine macrophage precursors, in a dose‐dependent manner, whereas no inhibition was observed by adding osteoprotegerin, RANK:Fc, TNFα, or interleukin‐8 or by blocking the LIGHT receptors herpesvirus entry mediator or lymphotoxin β receptor. However, formation of osteoclasts was significantly decreased by the soluble decoy receptor for LIGHT, DcR3, and by blocking antibodies to the p75 component of the TNF receptor. A significant increase in LIGHT levels in the serum of RA patients compared with normal controls was also noted.ConclusionOur results indicate that LIGHT promotes RANKL‐mediated osteoclastogenesis and that it can induce osteoclast formation by a mechanism independent of RANKL. The increased concentration of LIGHT in patients with RA raises the possibility that LIGHT may play a role in immunopathogenic conditions that are associated with localized or systemic bone loss.
Evaluation of the alkaline Comet assay conducted with the wetlands plant Bacopa monnieri L. as a model for ecogenotoxicity assessment
Authors: Vajpayee Poornima , Dhawan Alok , Shanker Rishi 
Published: April 2006

AbstractWetlands play a key role in maintaining environmental quality, and wetlands plants could serve as model organisms for determining the genotoxic effects of pollutants contaminating these areas. In the present study, DNA damage was evaluated in a wetlands plant, Bacopa monnieri L., as a potential tool for the assessment of ecogenotoxicity. The Comet assay was used for detecting DNA damage in B. monnieri exposed to two model mutagens, ethyl methanesulfonate (EMS) and methyl methanesulfonate (MMS). Significant (P < 0.05) dose‐dependent increases in DNA damage were observed following treatments conducted by exposing both isolated nuclei (acellular or in vitro exposure) and whole plants (in vivo exposure) to 0.01–5 mM EMS and 0.05–100 μM MMS for 2 hr at (26 ± 2)°C. The assay was then used to evaluate the genotoxic potential of cadmium (Cd), a wetlands contaminant. In vitro exposure of nuclei from untreated leaves to 0.001–200 μM Cd for 2 hr resulted in significant (P < 0.05) levels of DNA damage. Cd concentrations ≥0.01 μM induced DNA damage as evidenced by increases in the Olive tail moment. In vivo exposure of plants to 0.01–500 μM Cd for 2, 4, and 18 hr resulted in dose‐ and time‐dependent increases in DNA damage in the nuclei isolated from roots and leaves. Cd‐induced DNA damage was greater in roots than leaves. To our knowledge, this is the first report describing the use of a wetlands plant for genotoxicity assessment, using the Comet assay. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.
Porous hybrid structures based on P(DLLA‐co‐TMC) and collagen for tissue engineering of small‐diameter blood vessels
Authors: Buttafoco Laura , Boks Niels P. , Engbers‐Buijtenhuijs Paula , Grijpma Dirk W. , Poot Andre A. , Dijkstra Piet J. , Vermes Istvan , Feijen Jan 
Published: April 2006

AbstractPoly (D,L‐lactide)‐7co‐(1,3‐trimethylene carbonate) [P(DLLA‐co‐TMC)] (83 mol % DLLA) was used to produce matrices suitable for tissue engineering of small‐diameter blood vessels. The copolymer was processed into tubular structures with a porosity of ∼98% by melt spinning and fiber winding, thus obviating the need of organic solvents that may compromise subsequent cell culture. Unexpectedly, incubation in culture medium at 37°C resulted in disconnection of the contact points between the polymer fibers. To improve the structural stability of these P(DLLA‐co‐TMC) scaffolds, a collagen microsponge was formed inside the pores of the synthetic matrix by dip coating and freeze drying. Hybrid structures with a porosity of 97% and an average pore size of 102 μm were obtained. Structural stability was preserved during incubation in culture medium at 37°C. Smooth‐muscle cells (SMCs) were seeded in these hybrid scaffolds and cultured under pulsatile flow conditions in a bioreactor (120 beats/min, 80–120 mmHg). After 7 days of culture in a dynamic environment viable SMCs were homogeneously distributed throughout the constructs, which were five times stronger and stiffer than noncultured scaffolds. Values for yield stress (2.8 ± 0.6 MPa), stiffness (1.6 ± 0.4 MPa), and yield strain (120% ± 20%) were comparable to those of the human artery mesenterica. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Experimental Requirements for an Efficient Control of Free‐Radical Polymerizations via the Reversible Addition‐Fragmentation Chain Transfer (RAFT) Process
Authors: Favier Arnaud , Charreyre Marie‐Thérèse 
Published: April 2006

AbstractSummary: Reversible addition‐fragmentation chain transfer (RAFT) polymerization is a recent and very versatile controlled radical polymerization technique that has enabled the synthesis of a wide range of macromolecules with well‐defined structures, compositions, and functionalities. The RAFT process is based on a reversible addition‐fragmentation reaction mediated by thiocarbonylthio compounds used as chain transfer agents (CTAs). A great variety of CTAs have been designed and synthesized so far with different kinds of substituents. In this review, all of the CTAs encountered in the literature from 1998 to date are reported and classified according to several criteria : i) the structure of their substituents, ii) the various monomers that they have been polymerized with, and iii) the type of polymerization that has been performed (solution, dispersed media, surface initiated, and copolymerization). Moreover, the influence of various parameters is discussed, especially the CTA structure relative to the monomer and the experimental conditions (temperature, pressure, initiation, CTA/initiator ratio, concentration), in order to optimise the kinetics and the efficiency of the molecular‐weight‐distribution control.Schematic of the RAFT polymerization.magnified imageSchematic of the RAFT polymerization.
Synthesis of poly(ethylene oxide) with pending 2,2,6,6‐tetramethylpiperidine‐1‐oxyl groups and its further initiation of the grafting polymerization of styrene
Authors: Jia Zhongfan , Fu Qiang , Huang Junlian 
Published: April 2006

AbstractA new stratagem for the synthesis of amphiphilic graft copolymers of hydrophilic poly(ethylene oxide) as the main chain and hydrophobic polystyrene as the side chains is suggested. A poly(ethylene oxide) with pending 2,2,6,6‐tetramethylpiperidine‐1‐oxyls [poly(4‐glycidyloxy‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐co‐ethylene oxide)] was first prepared by the anionic ring‐opening copolymerization of ethylene oxide and 4‐glycidyloxy‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl, and then the graft copolymerization of styrene was completed with benzoyl peroxide as the initiator in the presence of poly(4‐glycidyloxy‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐co‐ethylene oxide). The polymerization of styrene was under control, and comblike, amphiphilic poly(ethylene oxide)‐g‐polystyrene was obtained. The copolymer and its intermediates were characterized with size exclusion chromatography, 1H NMR, and electron spin resonance in detail. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3836–3842, 2006
Room temperature electroluminescence from multilayer GeSi heterostructures
Authors: Tonkikh A. A. , Cirlin G. E. , Talalaev V. G. , Zakharov N. D. , Werner P. 
Published: April 2006

AbstractDetails of silicon diodes with Ge/Si multilayer quantum dot heterostructures embedded in the Si p–n junction grown by molecular beam epitaxy emitting in the range of 1.4–1.7 µm at room temperature and continuous injection pumping are discussed. Output power of the light emitting diode reaches 1 µW/cm2 at applied current density of 2 A/cm2. Photoluminescence and transmission electron microscopy show that the origin of intense luminescence is defect free stacked Ge quantum dot array formed inside the structure. It is shown that doping by antimony improves structure quality and increases photoluminescence efficiency at room temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐situ monitoring of laser annealing by micro‐Raman spectroscopy for hydrogenated silicon nanoparticles produced in radio frequency glow discharge
Authors: Hill D. , Jawhari T. , Cespedes J. García , García J. Alvarez , Bertran E. 
Published: April 2006

AbstractLow temperature Plasma Enhanced Chemical Vapour Deposition (PECVD) grown amorphous hydrogenated Si (a‐Si:H) thin films form the basis of many photovoltaic and microelectronic devices such as solar cells and TFTs. Amorphous hydrogenated silicon in the form of nanoparticles has been produced by power modulation of the PECVD processes. The stability of these nanoparticles under high temperatures and high power illumination is therefore of interest and to this end we report on combined laser annealing and in‐situ monitoring through the use of micro‐raman spectroscopy. Interpretation of spectra is done with the help of complementary techniques including scanning (SEM) and transmission electron microscopy (TEM). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Integrating nanotubes into microsystems with electron beam lithography and in situ catalytically activated growth
Authors: Gjerde K. , Mora M. F. , Kjelstrup‐Hansen J. , Schurmann T. , Gammelgaard L. , Aono M. , Teo K. B. K , Milne W. I. , Bøggild P. 
Published: April 2006

AbstractIntegration of freestanding wire‐like structures such as multi walled carbon nanotubes (MWCNT) into microsystems has many potential applications. Devices such as AFM tips or improved electrodes for conductivity measurements are obvious candidates. Catalytically activated growth opens up the possibility of waferscale fabrication of such devices. We combine conventional microfabrication techniques with state of the art electron beam lithography (EBL) to precisely position catalyst nanoparticles with sub 100 nm diameter into the microsystems. In particular, we have explored two main approaches which allow the catalyst material deposition to occur after the microfabrication is finished, thus avoiding contamination of cleanroom equipment. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear long waves generated by a moving pressure disturbance
Authors: Casciola C. M. , Landrini M. 
Published: April 2006

The evolution of long waves generated by a pressure disturbance acting on an initially unperturbed free surface in a channel of finite depth is analysed. Both off-critical and transcritical conditions are considered in the context of the fully nonlinear inviscid problem. The solution is achieved by using an accurate boundary integral approach and a time-stepping procedure for the free-surface dynamics.The discussion emphasizes the comparison between the present results and those provided by both the Boussinesq and the related Korteweg–de Vries model. For small amplitudes of the forcing, the predictions of the asymptotic theories are essentially confirmed. However, for finite intensities of the disturbance, several new features significantly affect the physical results. In particular, the interaction among different wave components, neglected in the Korteweg–de Vries approximation, is crucial in determining the evolution of the wave system. A substantial difference is indeed observed between the solutions of the Korteweg–de Vries equation and those of both the fully nonlinear and the Boussinesq model. For increasing dispersion and fixed nonlinearity the agreement between the Boussinesq and fully nonlinear description is lost, indicating a regime where dispersion becomes dominant.Consistently with the long-wave modelling, the transcritical regime is characterized by an unsteady flow and a periodic emission of forward-running waves. However, also in this case, quantitative differences are observed between the three models. For larger amplitudes, wave steepening is almost invariably observed as a precursor of the localized breaking commonly detected in the experiments. The process occurs at the crests of either the trailing or the upstream-emitted wave system for Froude numbers slightly sub- and super-critical respectively.
Folate synthesis in plants: purification, kinetic properties, and inhibition of aminodeoxychorismate synthase
Authors: Sahr Tobias , Ravanel Stéphane , Basset Gilles , Nichols Brian P. , Hanson Andrew D. , Rébeillé Fabrice 
Published: April 2006

pABA (p-aminobenzoate) is a precursor of folates and, besides esterification to glucose, has no other known metabolic fate in plants. It is synthesized in two steps from chorismate and glutamine, the first step being their conversion into glutamate and ADC (4-aminodeoxychorismate). In Escherichia coli, two proteins forming a heterodimeric complex are required for this reaction, but, in plants and lower eukaryotes, a single protein is involved. The Arabidopsis enzyme was expressed in E. coli and was purified to homogeneity. The monomeric enzyme (95 kDa) catalyses two reactions: release of NH3 from glutamine (glutaminase activity) and substitution of NH3 for the hydroxy group at position 4 of chorismate (ADC synthase activity). The kinetic parameters of the plant enzyme are broadly similar to those of the bacterial complex, with Km values for glutamine and chorismate of 600 and 1.5 μM respectively. As with the bacterial enzyme, externally added NH3 was a very poor substrate for the plant enzyme, suggesting that NH3 released from glutamine is preferentially channelled to chorismate. The glutaminase activity could operate alone, but the presence of chorismate increased the efficiency of the reaction 10-fold, showing the interdependency of the two domains. The plant enzyme was inhibited by dihydrofolate and its analogue methotrexate, a feature never reported for the prokaryotic system. These molecules were inhibitors of the glutaminase reaction, competitive with respect to glutamine (Ki values of 10 and 1 μM for dihydrofolate and methotrexate respectively). These findings support the view that the monomeric ADC synthase is a potential target for antifolate drugs.