bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predominance of cyclooxygenase 1 over cyclooxygenase 2 in the generation of proinflammatory prostaglandins in autoantibody‐driven K/BxN serum–transfer arthritis
Authors: Chen Mei , Boilard Eric , Nigrovic Peter A. , Clark Patsy , Xu Daigen , FitzGerald Garret A. , Audoly Laurent P. , Lee David M. 
Published: April 2008

AbstractObjectiveProstaglandins (PGs) are found in high levels in the synovial fluid of patients with rheumatoid arthritis, and nonsteroidal blockade of these bioactive lipids plays a role in patient care. The aim of this study was to explore the relative contribution of cyclooxygenase (COX) isoforms and PG species in the autoantibody‐driven K/BxN serum–transfer arthritis.MethodsThe prostanoid content of arthritic ankles was assessed in ankle homogenates, and the importance of this pathway was confirmed with pharmacologic blockade. The presence of COX isoforms was assessed by Western blotting and their functional contribution was compared using COX‐1−/− and COX‐2−/− mice as well as isoform‐specific inhibitors. The relative importance of PGE2 and PGI2 (prostacyclin) was determined using mice deficient in microsomal PGE synthase 1 (mPGES‐1) and in the receptors for PGI2.ResultsHigh levels of PGE2 and 6‐keto‐PGF1α (a stable metabolite of PGI2) were detected in arthritic joint tissues, correlating strongly with the intensity of synovitis. Pharmacologic inhibition of PG synthesis prevented arthritis and ameliorated active disease. While both COX isoforms were found in inflamed joint tissues, only COX‐1 contributed substantially to clinical disease; COX‐1−/− mice were fully resistant to disease, whereas COX‐2−/− mice remained susceptible. These findings were confirmed by isoform‐specific pharmacologic inhibition. Mice lacking mPGES‐1 (and therefore PGE2) developed arthritis normally, whereas mice incapable of responding to PGI2 exhibited a significantly attenuated arthritis course, confirming a role of PGI2 in this arthritis model.ConclusionThese findings challenge previous paradigms of distinct “housekeeping” versus inflammatory functions of the COX isoforms and highlight the potential pathogenic contribution of prostanoids synthesized via COX‐1, in particular PGI2, to inflammatory arthritis.
Outcomes of obese and nonobese patients undergoing revision total hip arthroplasty
Authors: Lübbeke Anne , Moons Karel G. M. , Garavaglia Guido , Hoffmeyer Pierre 
Published: April 2008

AbstractObjectiveTo evaluate the effect of obesity on the incidence of adverse events (surgical site infection, dislocation, re‐revision, or ≥1 adverse event), functional outcome, residual pain, and patient satisfaction after revision total hip arthroplasty (THA).MethodsWe conducted a university hospital‐based prospective cohort study including 52 obese and 152 nonobese patients with revision THA performed between 1996 and 2006. We used incidence rates, rate ratios, and hazard ratios (HRs) to compare the incidence of events in obese and nonobese patients and in 4 body mass index (BMI) categories (<25, 25–29.9, 30–34.9, ≥35). Functional outcome and pain were measured 5 years postoperative using the Harris Hip Score.ResultsThe incidence rate for ≥1 complication increased with rising BMI (1.8, 3.4, 10.3, and 17.9 cases/100 person‐years). The increase was small between normal and overweight patients (adjusted HR 1.5, 95% confidence interval [95% CI] 0.5, 4.7), significantly greater with BMI 30–34.9 (adjusted HR 4.5, 95% CI 1.4, 14.0), and most evident with BMI ≥35 (adjusted HR 10.9, 95% CI 2.9, 41.1). The adjusted HR for surgical site infection (obese versus nonobese) was 4.1 (95% CI 1.1, 15.0) and for dislocation 3.5 (95% CI 1.3, 9.3). Eighty patients had a followup visit at 5 years. Obese patients had moderately lower functional results and higher levels of residual pain, but patient satisfaction was almost similar.ConclusionRevision THA is technically challenging, particularly in obese patients, probably due to more difficult anatomic conditions. We found an increased risk of adverse events, notably surgical site infection and dislocation in these patients.
Measuring clinical enthesitis in psoriatic arthritis: Assessment of existing measures and development of an instrument specific to psoriatic arthritis
Authors: Healy Paul J. , Helliwell Philip S. 
Published: April 2008

AbstractObjectiveTo assess currently available tools for measurement of enthesitis and to develop a new instrument specifically for use in psoriatic arthritis (PsA).MethodsTwenty‐eight patients with PsA underwent clinical assessment over a period of 6 months after change of disease‐modifying therapy, usually to methotrexate. Measures of enthesitis included the Mander Enthesitis Index (MEI), the Maastricht Ankylosing Spondylitis Enthesitis Score, the Major index, and the Gladman index. Data from these assessments were used to develop a new enthesitis index, the Leeds Enthesitis Index (LEI).ResultsAn iterative process of data reduction enabled derivation of the LEI index, which consisted of 6 sites: right and left Achilles insertions, medial femoral condyles, and lateral epicondyles of the humerus. All measures showed significant change from baseline but only the LEI and Gladman indices showed a large effect size. All indices demonstrated a floor effect (a score of 0 when the MEI is >0) but this was minimal for the LEI index. All indices correlated strongly with each other and other measures of disease activity.ConclusionThe LEI is a new enthesitis index designed for use in PsA. It shows good test characteristics that suggest it will be a robust and reliable assessment tool. We suggest that it be adopted for use in any randomized controlled trials and longitudinal observation cohorts involving patients with PsA.
Confirmatory factor analysis of the Arthritis Impact Measurement Scales 2 short form in patients with rheumatoid arthritis
Authors: ten Klooster Peter M. , Veehof Martine M. , Taal Erik , van Riel Piet L. C. M. , van de Laar Mart A. F. J. 
Published: April 2008

AbstractObjectiveTo examine the factorial validity of the short form Arthritis Impact Measurement Scales 2 (AIMS2‐SF) in patients with rheumatoid arthritis (RA).MethodsData were from a sample of 279 patients with active RA who completed the long form AIMS2 before starting treatment with tumor necrosis factor α–blocking agents. Confirmatory factor analyses were conducted to test and compare the fit of the currently used theoretical measurement model of the AIMS2‐SF, originally suggested for the long form AIMS2, and 2 alternative models based on previous exploratory research.ResultsA model with the physical dimension divided into upper and lower body limitations was superior to the current model, and both models provided a clearly better fit than a model without a separate symptom dimension. Under the restrictive assumption of uncorrelated error terms, none of the models achieved a consistent and acceptable fit as judged by several goodness‐of‐fit indices. Allowing error covariances between 6 pairs of items within the same dimension resulted in an improved and acceptable fit of both the current model and the model with a separate upper and lower body component.ConclusionThis study generally supports the factorial validity of the AIMS2‐SF and suggests the use of separate scores for upper and lower body limitations. Further research is needed to resolve the issue of high error correlations associated with particular items.
Controlling kinesin motor proteins in nanoengineered systems through a metal‐binding on/off switch
Authors: Greene Adrienne C. , Trent Amanda M. , Bachand George D. 
Published: April 2008

AbstractA significant challenge in utilizing kinesin biomolecular motors in integrated nanoscale systems is the ability to regulate motor function in vitro. Here we report a versatile mechanism for reversibly controlling the function of kinesin biomolecular motors independent of the fuel supply (ATP). Our approach relied on inhibiting conformational changes in the neck‐linker region of kinesin, a process necessary for microtubule transport. We introduced a chemical switch into the neck‐linker of kinesin by genetically engineering three histidine residues to create a Zn2+‐binding site. Gliding motility of microtubules by the mutant kinesin was successfully inhibited by ≥10 µM Zn2+, as well as other divalent metals. Motility was successfully restored by removal of Zn2+ using a number of different chelators. Lastly, we demonstrated the robust and cyclic nature of the switch using sequential Zn2+/chelator additions. Overall, this approach to controlling motor function is highly advantageous as it enables control of individual classes of biomolecular motors while maintaining a consistent level of fuel for all motors in a given system or device. Biotechnol. Bioeng. 2008;101: 478–486. © 2008 Wiley Periodicals, Inc.
Valorization of onion waste and by‐products: MCR‐ALS applied to reveal the compositional profiles of alcoholic fermentations of onion juice monitored by near‐infrared spectroscopy
Authors: González‐Sáiz José‐María , Esteban‐Díez Isabel , Rodríguez‐Tecedor Sofía , Pizarro Consuelo 
Published: April 2008

AbstractThe overall purpose of the project, of which this study is a part, was to examine the feasibility of onion waste as a support‐substrate for the profitable production of food‐grade products. This study focused on the efficient production of ethanol from worthless onions by transforming the onion juice into onion liquor via alcoholic fermentation with the yeast Saccharomyces cerevisiae. The onion bioethanol produced could be later used as a favorable substrate for acetic fermentation to finally obtain onion vinegar. Near‐infrared spectroscopy (NIRS), coupled with the multivariate curve resolution‐alternating least squares (MCR‐ALS) method, has been used to reveal the compositional and spectral profiles for both substrates and products of alcoholic fermentation runs, that is, total sugars, ethanol, and biomass concentration. The ambiguity associated with the ALS calculation was resolved by applying suitable inequality and equality constraints. The quality of the results provided by the NIR‐based MCR‐ALS methodology adopted was evaluated by several performance indicators, including the variance explained by the model, the lack of fit and the agreement between the MCR‐ALS achieved solution and the results computed by applying previously validated PLS reference models. An additional fermentation run was employed to test the actual predictive ability of the ALS model developed. For all the components resolved in the fermentation system studied (i.e., total sugars, ethanol, and biomass), the final model obtained showed a high predictive ability and suitable accuracy and precision, both in calibration and external validation, confirmed by the very good agreement between the ALS responses and the reference values (the coefficient of determination was, in all cases, very close to 1, and the statistics confirmed that no significant difference was found between PLS reference models and the MCR‐ALS methodology applied). Thus, the proven reliability of the MCR‐ALS model presented in this study, based only on NIR measurements, makes it suitable for monitoring of the key species involved in the alcoholic fermentation of onion juice, allowing the process to be modeled and controlled in real time. Biotechnol. Bioeng. 2008;101: 776–787. © 2008 Wiley Periodicals, Inc.
Der Eisbär: Postertier mit ungewisser Zukunft. Überlebensspezialist der Arktis
Authors: Breiter Matthias 
Published: April 2008

AbstractEisbären sind Überlebenskünstler, die zahlreiche Anpassungen sowohl in morphologischer Hinsicht als auch in Bezug auf ihre Verhaltensweisen aufweisen, um in der Arktis zu überleben. Noch heute ist unser Verständnis von den Tieren lückenhaft und zum Teil von Vorurteilen behaftet. Die Schwierigkeiten, die Tiere in ihrem natürlichen Lebensraum auf dem Packeis zu beobachten, spielen dabei eine große Rolle. Ein weiter Grund ist, dass uns Menschen der arktische Lebensraum prinzipiell fremd ist und lebensfeindlich erscheint. Dadurch haben wir die Tendenz, Aspekte, die uns Probleme bereiten, wie die Kälte, überzubewerten, und andere Aspekte, wie den Wasserhaushalt, kaum zu beachten. Die Zukunft der Eisbären wird davon abhängen, dass wir ihre Bedürfnisse besser verstehen, um eine Koexistenz zu ermöglichen. Die Problematik der industriellen Nutzung der Arktis, einer Begleiterscheinung der globalen Erwärmung, findet zu wenig Beachtung. Die jeweiligen verantwortlichen Regierungen schenken in dieser Hinsicht bisher wirtschaftlichen Interessen wesentlich mehr Aufmerksamkeit als Umweltfragen.
Constantin Mereschkowsky
Authors: Höxtermann Ekkehard 
Published: April 2008

AbstractConstantin Mereschkowsky gilt als Begründer der Symbiogenesetheorie der Entstehung eukaryoter Zellen (1905). Zu Lebzeiten umstritten, gerieten seine Ideen weitgehend in Vergessenheit und erfuhren erst in den 1990er Jahren eine Renaissance. Die Wiederentdeckung des Werkes offenbarte zugleich das unstete Leben eines heimatlosen Mannes, das tragisch endete.
Neues Unterrichtsmaterial des Nationalen Genomforschungsnetzes auf CD‐ROM
Authors: Krüger Olaf 
Published: April 2008

AbstractDas komplexe Wissen zur Humangenomforschung fundiert und trotzdem anschaulich und spannend zu vermitteln, ist eine Herausforderung für jeden Lehrer. Damit dieses Kunststück noch besser gelingt, hat das Nationale Genomforschungsnetz (NGFN, www.ngfn.de) das Unterrichtsmaterial “GENial einfach!” entwickelt, das kostenlos erhältlich ist.
Synthesis and Screening of an Oroidin Library against Pseudomonas aeruginosa Biofilms
Authors: Richards Justin J. , Ballard T. Eric , Huigens Robert W. , Melander Christian 
Published: April 2008

AbstractA 50‐compound library based on the marine natural product oroidin was synthesized and assayed for anti‐biofilm activity against PAO1 and PA14, two strains of the medically relevant γ‐proteobacterium Pseudomonas aeruginosa. Through structure–activity relationship (SAR) analysis of analogues based on the oroidin template, several conclusions can be drawn as to what structural properties of the synthetic derivatives are necessary to elicit a biological response. Notably, the most active analogues identified were those that contained a 2‐aminoimidazole (2‐AI) motif and a dibrominated pyrrolecarboxamide subunit. Here we disclose the synthesis and subsequently determined biological activity of this unique class of compounds as inhibitors of biofilm formation that have no direct antibiotic effect.
Reactors for Fischer‐Tropsch Synthesis
Authors: Guettel R. , Kunz U. , Turek T. 
Published: April 2008

AbstractThe Fischer‐Tropsch synthesis was discovered in Germany in the 1920s and has since been developed to industrial scale within a relatively short period of time. In the 21st century, the process is undergoing a renaissance, because an increasing fraction of liquid fuels will have to be produced from alternative raw materials like natural gas, coal or biomass in the future. On industrial scale, multitubular and bubble column reactors are used for this highly exothermic reaction. Due to several disadvantages of both reactor systems, new concepts are presently investigated. For intensification of mass transfer properties of multiphase reactors, alternative catalyst geometries like honeycombs, structured packings or foams are discussed. High catalyst utilization and isothermal operating conditions can be achieved in microstructured reactors. Furthermore, several membrane reactor concepts are under investigation. After an introduction to historical development and state of the art of Fischer‐Tropsch reactors, chances and challenges of new reactor technologies will be discussed.
Fuels and Fuel Cells: The “Right Way” from Fuels to Fuel Gas
Authors: Hennings U. , Brune M. , Wolf M. , Reimert R. 
Published: April 2008

AbstractFuel cells are considered for various applications as well as in connection with the use of several types of energy feedstocks, both fossil and renewable. Large and very particular challenges arise from the design of the fuel gas supply in connection with envisioned applications and different sorts of fuels. The design of the fuel gas supply must meet the requirements posed by the type of raw fuel, the conceived application and the type of fuel cell employed. In this work, the resulting large number of possible combinations is summarized by a graph, i.e., the “fan”. The graphic description is explained by means of selected examples.
Biofuels for Automobiles – An Overview
Authors: Schaub G. , Vetter A. 
Published: April 2008

AbstractDue to increasing oil prices and climate change concerns, biofuels have become more important as potential alternative energy sources. It is an open question as to which types of biofuels have the best yield potentials, characteristic properties and environmental consequences for providing the largest contribution to future energy requirements. Apart from the quality aspects, the question of quantity is very important, i.e., yields of biomass raw materials from agriculture and forestry as well as the conversion efficiencies/yields of the conversion process to automotive fuels. The most widely used biofuel forms today are fatty acid methyl esters and ethanol. However, in the future it is possible that synthetic hydrocarbons and hydrogen, produced via biotechnological or chemical processes may become feasible as fuel sources. Limitations in quantity are caused by net productivities of photosynthesis, which are limited by several factors, e.g., by the supply of water, limited availability of land, and conversion losses. As a consequence, biofuels as they exist can only contribute to a limited extent to securing raw material supplies for energy requirements in the future. Efficiency improvements in processing technologies and changes in consumer behavior and attitude will also be required.
Succinic Acid: A New Platform Chemical for Biobased Polymers from Renewable Resources
Authors: Bechthold I. , Bretz K. , Kabasci S. , Kopitzky R. , Springer A. 
Published: April 2008

AbstractSuccinic acid is predicted to be one of the future platform chemicals that can be derived from renewable resources. The improvements in biotechnological succinic acid production are presented. Chemical conversion pathways to γ‐butyrolactone, tetrahydrofuran, 1,4‐butanediole, and pyrrolidones are reviewed. An overview of possible new biopolymers (e. g. polyesters, polyamides, and poly(ester amide)s) based on succinic acid and its derivatives is given. Nevertheless, industrial processes using purified succinic acid from fermentation broths are not state of the art yet. Further improvements are needed until succinic acid‐based chemical production will be economically favorable.
Fischer‐Tropsch Catalysts for the Biomass‐to‐Liquid (BTL)‐Process
Authors: van Steen E. , Claeys M. 
Published: April 2008

AbstractThe Fischer‐Tropsch synthesis is at the heart of the Biomass‐to‐Liquids (BTL) process. Feasibility studies published in open literature typically consider cobalt‐based catalysts for the Fischer‐Tropsch synthesis. Here, we present an overview on the history and development up until the present for both cobalt‐ and iron‐based Fischer‐Tropsch catalysts. The role of the support material and various other additives to the catalyst formulation are discussed in detail with regard to activity, catalyst deactivation, and selectivity. Tentative explanations for e.g. the observed size dependency in cobalt‐based catalysts and phase transformations in iron‐based Fischer‐Tropsch catalysts are offered. The productivity of cobalt‐based catalysts at high conversion level is currently higher than that of iron‐based catalysts. Nevertheless, it is argued that iron‐based catalysts may be an attractive option for the BTL‐process, since it is much cheaper, impacting on the cost of the process due to inevitable process set‐ups in industrial operation. Improvement of current iron‐based catalysts is however desired.
Direct Liquefaction of Biomass
Authors: Behrendt F. , Neubauer Y. , Oevermann M. , Wilmes B. , Zobel N. 
Published: April 2008

AbstractReserves of fossil primary energy carriers are limited. Consequently liquid secondary energy carriers especially for mobile applications made from fossil reserves will not carry on forever but need to be replaced in a not‐to‐far future. Two substitution strategies are currently under investigation – the use of oil from plant seeds either directly or after chemical modification (biodiesel) or the gasification of complete plants, use of the product gases (mainly CO and H2) in a Fischer‐Tropsch process with subsequent refining. A third possible pathway would be the so‐called direct liquefaction, i.e., the conversion of complete plants into liquid fuels without gasification. This process is discussed and various technical implementations are critically evaluated in the present paper.
Motor Fuels From Biomass Pyrolysis
Authors: Barth T. , Kleinert M. 
Published: April 2008

AbstractDifferent pyrolysis techniques for converting solid biomass material into liquid fuels that can be used in combustion motors are described and compared. The techniques include fast pyrolysis, pyrolysis in aqueous reaction media and a newly developed process based on a hydrogen donating solvent system and used for converting residual lignin after production of lignocellulosic ethanol production to liquids. New data from pyrolysis in liquid reaction media is presented and discussed. The quality of the oil as produced in the pyrolysis step is evaluated, and the range of different possible applications is emphasized.
Oxoanion Binding by Guanidiniocarbonylpyrrole Cations in Water: A Combined DFT and MD Investigation
Authors: Moiani Davide , Cavallotti Carlo , Famulari Antonino , Schmuck Carsten 
Published: April 2008

AbstractStructures and properties of nonbonding interactions involving guanidinium‐functionalized hosts and carboxylate substrates were investigated by a combination of ab initio and molecular dynamics approaches. The systems under study are on one hand intended to be a model of the arginine–anion bond, so often observed in proteins and nucleic acids, and on the other to provide an opportunity to investigate the influence of molecular structure on the formation of supramolecular complexes in detail. Use of DFT calculations, including extended basis sets and implicit water treatment, allowed us to determine minimum‐energy structures and binding enthalpies that compared well with experimental data. Intermolecular forces were found to be mostly due to electrostatic interactions through three hydrogen bonds, one of which is bifurcate, and are sufficiently strong to induce a conformational change in the ligand consisting of a rotation of about 180° around the guanidiniocarbonylpyrrole axis. Free binding energies of the complexes were evaluated through MD simulations performed in the presence of explicit water molecules by use of the molecular mechanics Poisson–Boltzmann solvent accessible surface area (MM‐PBSA) and linear interaction energy (LIE) approaches. LIE energies were in quantitative agreement with experimental data. A detailed analysis of the MD simulations revealed that the complexes cannot be described in terms of a single binding structure, but that they are characterized by a significant internal mobility responsible for several low‐energy metastable structures.