bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative justification for target concentration intervention – parameter variability and predictive performance using population pharmacokinetic models for aminoglycosides
Authors: Matthews Ivan , Kirkpatrick Carl , Holford Nicholas 
Published: June 2004

Aims  [1] To quantify the random and predictable components of variability for aminoglycoside clearance and volume of distribution [2] To investigate models for predicting aminoglycoside clearance in patients with low serum creatinine concentrations [3] To evaluate the predictive performance of initial dosing strategies for achieving an aminoglycoside target concentration.Methods  Aminoglycoside demographic, dosing and concentration data were collected from 697 adult patients (>=20 years old) as part of standard clinical care using a target concentration intervention approach for dose individualization. It was assumed that aminoglycoside clearance had a renal and a nonrenal component, with the renal component being linearly related to predicted creatinine clearance.Results  A two compartment pharmacokinetic model best described the aminoglycoside data. The addition of weight, age, sex and serum creatinine as covariates reduced the random component of between subject variability (BSVR) in clearance (CL) from 94% to 36% of population parameter variability (PPV). The final pharmacokinetic parameter estimates for the model with the best predictive performance were: CL, 4.7 l h–1 70 kg–1; intercompartmental clearance (CLic), 1 l h–1 70 kg–1; volume of central compartment (V1), 19.5 l 70 kg–1; volume of peripheral compartment (V2) 11.2 l 70 kg–1.Conclusions  Using a fixed dose of aminoglycoside will achieve 35% of typical patients within 80–125% of a required dose. Covariate guided predictions increase this up to 61%. However, because we have shown that random within subject variability (WSVR) in clearance is less than safe and effective variability (SEV), target concentration intervention can potentially achieve safe and effective doses in 90% of patients.
Determining the reporting quality of RCTs in clinical pharmacology
Authors: Mills Edward , Loke Yoon K. , Wu Ping , Montori Victor M. , Perri Daniel , Moher David , Guyatt Gordon 
Published: June 2004

Background  The Consolidated Standards for Reporting Trials (CONSORT) are recommendations for improving the quality of reports of randomized controlled trials (RCTs).Objective  To determine the extent to which clinical pharmacology journals implement specific CONSORT recommendations.Design and setting  Analysis of RCTs published between May 2002 and May 2003 in four clinical pharmacology journals.Main outcome measures  Proportion of RCTs that published a participant flow diagram and that reported on randomization and restriction methods, allocation concealment, blinding, intention‐to‐treat analysis, ethical considerations, adverse events and source of funding.Results  Of 482 clinical trials, 193 were RCTs. Healthy participants were involved in 129 [66.8%, 95% confidence interval (CI) 59.9, 73.1] trials, patients who required treatment in 61 (31.6%, 95% CI 25.4, 38.4) trials and both in three (1.6%, 95% CI 0.5, 4.4) trials. The following items were infrequently reported: sequence generation (17%), allocation concealment (3%), use of restriction (16%), description of blinding (26%), and flow diagrams of study participants (2%). In contrast, the following areas were often reported: use of intention‐to‐treat analysis (79%), description of withdrawals (92.2%) and description of adverse events (71%), ethics review (94%) and informed consent (95%). Sources of funding were reported in 56% of studies.Conclusion  The use of the selected CONSORT items is limited in these journals, possibly as many items may not be relevant to the types of studies published in clinical pharmacology journals. Further efforts are required to determine the applicability of CONSORT to RCTs in clinical pharmacology.
Remote sensing of upland vegetation: the potential of high spatial resolution satellite sensors
Authors: Mehner Henny , Cutler Mark , Fairbairn David , Thompson Gillian 
Published: June 2004

ABSTRACTAim  Traditional methodologies of mapping vegetation, as carried out by ecologists, consist primarily of field surveying or mapping from aerial photography. Previous applications of satellite imagery for this task (e.g. Landsat TM and SPOT HRV) have been unsuccessful, as such imagery proved to have insufficient spatial resolution for mapping vegetation. This paper reports on a study to assess the capabilities of the recently launched remote sensing satellite sensor Ikonos, with improved capabilities, for mapping and monitoring upland vegetation using traditional image classification methods.Location  The location is Northumberland National Park, UK.Methods  Traditional remote sensing classification methodologies were applied to the Ikonos data and the outputs compared to ground data sets. This enabled an assessment of the value of the improved spatial resolution of satellite imagery for mapping upland vegetation. Post‐classification methods were applied to remove noise and misclassified pixels and to create maps that were more in keeping with the information requirements of the NNPA for current management processes.Results The approach adopted herein for quick and inexpensive land cover mapping was found to be capable of higher accuracy than achieved with previous approaches, highlighting the benefits of remote sensing for providing land cover maps.Main conclusions  Ikonos imagery proved to be a useful tool for mapping upland vegetation across large areas and at fine spatial resolution, providing accuracies comparable to traditional mapping methods of ground surveys and aerial photography.
Dependence of broad‐scale geographical variation in fleshy‐fruited plant species richness on disperser bird species richness
Authors: Márquez Ana L. , Real Raimundo , Vargas J. Mario 
Published: June 2004

ABSTRACTAim  We analysed the interdependence of avian frugivore‐ and fruited plant‐species richness at the scale of major river basins across Europe, taking into account several environmental factors along different spatial gradients.Location  Continental Europe and the British Isles.Methods  We focused on wintering birds and autumn/winter fruiting plants, and used major river basins as geographical units and Structural Equation Modelling as the principal analytical tool.Results  The statistical influence of disperser species richness on fleshy‐fruited plant species richness is roughly double that of the reverse. Broad‐scale variation in frugivore richness is more dependent on environmental factors than on fruited plant richness. However, the influence of disperser richness on plant richness is four times higher than the influence of environmental factors. Environmental influences on both birds and plants are greater than purely spatial influences.Main conclusions  Our results are interpreted as indicating that biotic dispersal of fruits strongly affects broad‐scale geographical trends of fleshy‐fruited plant species richness, whereas richness of fruited plants moderately affects frugivore richness.
Connecting species richness, abundance and body size in deep‐sea gastropods
Authors: McClain Craig R. 
Published: June 2004

ABSTRACTAim  This paper examines species richness, abundance, and body size in deep‐sea gastropods and how they vary over depth, which is a strong correlate of nutrient input. Previous studies have documented the empirical relationships among these properties in terrestrial and coastal ecosystems, but a full understanding of how these patterns arise has yet to be obtained. Examining the relationships among macroecological variables is a logical progression in deep‐sea ecology, where patterns of body size, diversity, and abundance have been quantified separately but not linked together.Location  196–5042 m depth in the western North Atlantic.Method  Individuals analysed represent all Vetigastropoda and Caenogastropoda (Class Gastropoda) with intact shells, excluding Ptenoglossa, collected by the Woods Hole Benthic Sampling Program (3424 individuals representing 80 species). Biovolume was measured for every individual separately (i.e. allowing the same species to occupy multiple size classes) and divided into log2 body size bins. Analyses were conducted for all gastropods together and separated into orders and depth regions (representing different nutrient inputs). A kernel smoothing technique, Kolmogorov‐Smirnov test of fit, and OLS and RMA were used to characterize the patterns.Results  Overall, the relationship between the number of individuals and species is right skewed. There is also a positive linear relationship between the number of individuals and the number of species, which is independent of body size. Variation among these relationships is seen among the three depth regions. At depths inferred to correspond with intermediate nutrient input levels, species are accumulated faster given the number of individuals and shift from a right‐skewed to a log‐normal distribution.Conclusion  A strong link between body size, abundance, and species richness appears to be ubiquitous over a variety of taxa and environments, including the deep sea. However, the nature of these relationships is affected by the productivity regime and scale at which they are examined.
Ecological niches as stable distributional constraints on mammal species, with implications for Pleistocene extinctions and climate change projections for biodiversity
Authors: Martínez‐Meyer Enrique , Townsend Peterson A. , Hargrove William W. 
Published: June 2004

ABSTRACTAim Theoretical work suggests that species’ ecological niches should remain relatively constant over long‐term ecological time periods, but empirical tests are few. We present longitudinal studies of 23 extant mammal species, modelling ecological niches and predicting geographical distributions reciprocally between the Last Glacial Maximum and present to test this evolutionary conservatism.Location This study covered distributional shifts in mammal species across the lower 48 states of the United States.Methods We used a machine‐learning tool for modelling species’ ecological niches, based on known occurrences and electronic maps summarizing ecological dimensions, to assess the ability of ecological niches as modelled in one time period to predict the geographical distribution of the species in another period, and vice versa.Results High intertemporal predictivity between niche models and species’ occurrences indicate that niche conservatism is widespread among the taxa studied, particularly when statistical power is considered as a reason for failure of reciprocal predictions. Niche projections to the present for 8 mammal taxa that became extinct at the end of the Pleistocene generally increased in area, and thus do not support the hypothesis of niche collapse as a major driving force in their extinction.Main conclusions Ecological niches represent long‐term stable constraints on the distributional potential of species; indeed, this study suggests that mammal species have tracked consistent climate profiles throughout the drastic climate change events that marked the end of the Pleistocene glaciations. Many current modelling efforts focusing on anticipating climate change effects on species’ potential geographical distributions will be bolstered by this result — in essence, the first longitudinal demonstration of niche conservatism.
Scale and macroecological patterns in seed dispersal mutualisms
Authors: Burns K. C. 
Published: June 2004

ABSTRACTAlthough some studies of seed dispersal mutualisms have documented adaptive relationships between fruits and frugivores, others have shown that adaptive patterns are constrained by phylogenetic, historical or climatic effects. Variable results among studies have thwarted attempts to find a paradigm to unite the field and direct research. Two recent studies in Global Ecology and Biogeography exemplify this dichotomy. One paper reported adaptive relationships between abundances of birds and fruits, while the other study found that bird‐fruit abundance patterns were constrained by climatic effects. Almost paradoxically, both studies were conducted at the same locale. However, they focused on different spatio‐temporal scales. These results are surprisingly consistent with several other recent studies that have taken a macroecological approach. They also indicate that mutualistic relationships between fruits and frugivores are scale dependent. When viewed together, recent work suggests that the conflicting results of previous studies may result from spatio‐temporal variability of mutualistic relationships. This paper briefly reviews the emerging field of seed dispersal macroecology. A growing appreciation for scale appears to be leading the field in a new direction.
The Impact of Pump Speed and Inlet Cannulation Site on Left Ventricular Unloading with a Rotary Blood Pump
Authors: Vandenberghe Stijn , Nishida Takahiro , Segers Patrick , Meyns Bart , Verdonck Pascal 
Published: June 2004

Abstract: Background:  Ventricular assist devices are gaining ground in the therapeutic treatment of chronic heart failure. These devices are sometimes used as a bridge to recovery by unloading the left ventricle (LV) and restoring its function. It is therefore important to preserve the heart muscle and apply less invasive implantation methods.Methods:  In this study ventricular unloading was achieved in 7 healthy sheep with a rotary blood pump at different pump flow levels. Ventricular cannulation via the left atrium (LA) and through the mitral valve was compared to atrial cannulation. The unloading of the heart was assessed with LV pressure‐volume loops, derived energetic parameters, and an estimate of LV wall stress.Results:  No significant difference between the cannulations was found for any flow or pressure. LA cannulation, however, resulted in significantly lower stroke volumes and stroke work for all pump flow levels. Irrespective of cannulation site, LV volumes and energetic parameters showed a significant decrease with increasing pump flow.Conclusion:  LV assist with a rotary blood pump can provide sufficient unloading with atrial cannulation.
Preparation of Strong Acid Catalysts by Sulfate Treatment of Calcined Boehmite
Authors: Hochmann Tomáš , Setínek Karel 
Published: June 2004

Solid acid catalysts with acid strength of -14.52 < H0 < -8.2 were prepared by sulfate treatment of the samples of boehmite calcined at 105-800 °C. Two preparation methods were used: impregnation of the calcined boehmite with 3.5 M H2SO4 or mixing of the boehmite samples with anhydrous aluminum sulfate, in both cases followed by calcination in nitrogen at 650 °C. The catalysts were characterized by measurements of surface area, adsorption of pyridine and benzene, acid strength measurements by the indicator method and by catalytic activity tests in the isomerization of cyclohexene, p-xylene and n-hexane. Properties of the catalysts prepared by both methods were comparable.
DUALISM BETWEEN PHYSICAL FRAMES AND TIME IN QUANTUM GRAVITY
Authors: MERCURI SIMONE , MONTANI GIOVANNI 
Published: June 2004

In this work we present a discussion of the existing links between the procedures of endowing the quantum gravity with a real time and of including in the theory a physical reference frame. More precisely, as a first step, we develop the canonical quantum dynamics, starting from the Einstein equations in presence of a dust fluid and arrive at a Schrödinger evolution. Then, by fixing the lapse function in the path-integral of gravity, we get a Schrödinger quantum dynamics, of which eigenvalues problem provides the appearance of a dust fluid in the classical limit. The main issue of our analysis is to claim that a theory, in which the time displacement invariance, on a quantum level, is broken, is indistinguishable from a theory for which this symmetry holds, but a real reference fluid is included.
Comparative Activities of β-Lactam Antibiotics and Quinolones for Invasive <i>Streptococcus pneumoniae</i> Isolates
Authors: Öncü Serkan , Punar Metin , Eraksoy Haluk 
Published: June 2004

<i>Background: </i><i>Streptococcus pneumoniae</i> is a leading pathogen causing pneumonia, meningitis, otitis media, bacteremia and sinusitis resulting in significant morbidity and mortality. We examined in vitro activities of five quinolones in comparison with other antibiotics against 85 invasive pneumococcal isolates. <i>Methods: </i>Minimal inhibitory concentrations (MICs) of penicillin G, cefuroxime, azithromycin, clarithromycin, trimethoprim-sulfamethoxazole (SXT), ciprofloxacin, ofloxacin, levofloxacin, trovafloxacin and gemifloxacin were determined using a broth microdilution method. <i>Results: </i>The overall rates of resistance to penicillin (46%), cefuroxime (20%), azithromycin (20%), clarithromycin (18%) and SXT (46%) were considerable. Among all of the isolates, 9 isolates (11%) were highly resistant (MIC ≧2 mg/l) and 30 isolates (35%) had intermediate resistance (MIC 0.12– 1.0 mg/l). Of the quinolones gemifloxacin and trovafloxacin had the highest activity. The penicillin resistance status of the isolates did not have any effect on the resistance pattern of new quinolones. <i>Conclusion: </i>The new quinolones show great potential in the treatment of invasive infections caused by both penicillin-susceptible and penicillin-resistant pneumococci.
Preparation of Lithium Hexafluorophosphate from LiF and P in Fluorine Atmosphere
Authors: Kim Jae-Ho , Nagahara Kazushi , Yonezawa Susumu , Takashima Masayuki 
Published: June 2004

Abstract
Pure lithium hexafluorophosphate (LiPF6) has been successfully prepared by the reaction between the elemental fluorine and the equi-molar mixture of LiF and P (F2 direct method). The product was pure enough to be used as an electrolyte salt of lithium secondary battery. Especially, the stepwise introducing of fluorine gas into a reaction system was effective to prepare LiPF6 in a high yield. The results of Rietveld refinement of XRD data revealed that the structure of LiPF6 was trigonal (, Z = 3, a0 = 0.4932(2), c0 = 1.2641(5) nm, cell volume; 2.663(2) × 10−28 m3). The cell constants of LiPF6 prepared by the F2 direct method were almost the same as those of LiPF6 prepared by the reaction between LiF and PF5 in a liquid anhydrous hydrogen fluoride (L-AHF method).
Solid Phase Synthesis of Hydroxy Benzothiazepinones through Cyclative Release under Thermolysis
Authors: Kumar H M Sampath , Chakravarthy P Pawan , Rao M Shesha , Joyasawal Sipak , Yadav J S 
Published: June 2004

Abstract
Hydroxy benzothiazepinones were synthesized by a simple procedure involving epoxidation of polymer bound cinnamic acids followed by nucleophilic opening of the resulting glycidic ester by o-aminothiophenol to afford the intermediate hydroxy anilino-esters which underwent cyclization cleavage on heating in DMF to release the product completely.
Synthesis of Novel Spiro-condensed Dithienosiloles and the Application to Organic FET
Authors: Ohshita Joji , Lee Kwang-Hoi , Hamamoto Daisuke , Kunugi Yoshihito , Ikadai Junnai , Kwak Young-Woo , Kunai Atsutaka 
Published: June 2004

Abstract
Spirobi(dithienosilole)s were prepared and their optical and FET properties were studied. They showed absorption maxima at 358–368 nm, a little red shifted from those of the corresponding non-spiro type dithienosiloles, indicating that spiro-conjugation operates in these molecules to an extent. The field-effect hole mobility of spirobi[bis(trimethylsilyl)dithienosilole] was determined to be 1.4 × 10−6 cm2 V−1 s−1.
Nanotube Formation in Solution between β-Cyclodextrin and Cinchonine
Authors: Wen Xianhong , Guo Ming , Liu Ziyang , Tan Fei 
Published: June 2004

Abstract
The nanotube could been formed between the drug cinchonine and β-cyclodextrin in solution when they were mixed together and sonicated for about 1 h. Fluorescence anisotropy methods characterized the number of cyclodextrin in nanotube. AM1 calculation implied that H bonds played an important role to stabilize the nanostructure.
Photochromism of Furylfulgide in a Single-crystalline Phase
Authors: Kobatake Seiya , Irie Masahiro 
Published: June 2004

Abstract
(E)-2,5-Dimethyl-3-furylethylidene(isopropylidene)succinic anhydride (1E) was found to undergo photochromism in the single-crystalline phase. Upon irradiation with 366-nm light, the single crystal turned red. When the photogenerated colored crystal was observed under polarized light, the red color intensity changed by rotating the crystal. The colored crystal was stable at room temperature.
Cu–Pd Bimetallic Cluster/AC as a Novel Catalyst for the Reduction of Nitrate to Nitrite
Authors: Sakamoto Yoshinori , Nakata Kou , Kamiya Yuichi , Okuhara Toshio 
Published: June 2004

Abstract
Cu–Pd/AC catalysts that are derived from Cu–Pd clusters were shown to possess high activity for the reduction of nitrate to nitrite, but were inactive for the reduction of nitrite. In contrast, the Pd/AC catalyst was inactive for the reduction of nitrate, whereas conventional Cu–Pd/AC afforded various products, including nitrite, nitrogen, and ammonia.
The Effect of Ritonavir on the Pharmacokinetics of Meperidine and Normeperidine
Authors: Piscitelli Stephen C. , Kress Diane Rock , Bertz Richard J. , Pau Alice , Davey Richard 
Published: June 2004

Study Objective. To determine the effects of ritonavir on the pharmacokinetics of meperidine and normeperidine.Design. Open‐label, crossover, pharmacokinetic study.Setting. United States government research hospital.Subjects. Eight healthy volunteers who tested negative for the human immunodeficiency virus.Intervention. Subjects received oral meperidine 50 mg and had serial blood samples collected for 48 hours. They then received ritonavir 500 mg twice/day for 10 days, followed by administration of a second 50‐mg meperidine dose and collection of serial samples.Measurements and Main Results. Plasma samples were assayed for meperidine, normeperidine, and ritonavir. Meperidine's area under the curve (AUC) decreased in all subjects by a mean of 67 ± 4% in the presence of ritonavir (p<0.005). Mean ± SD maximum concentration was decreased from 126 ± 47 to 51 ± 21 ng/ml. Normeperidine's mean AUC was increased 47%, suggesting induction of hepatic metabolism.Conclusion. Meperidine's AUC is significantly reduced, not increased, by concomitant ritonavir. Based on these findings, the risk of narcotic‐related adverse effects from this combination appears to be minimal. However, increased concentrations of normeperidine suggest a potential for toxicity with increased dosages or long‐term therapy.