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We study optimal methods for Alternative Dispute Resolution (ADR), a technique to achieve settlement and avoid costly adversarial hearings. Participation is voluntary. Disputants are privately informed about their marginal cost of evidence provision. If ADR fails to engender settlement, the disputants can use the information obtained during ADR to determine what evidence to provide in an adversarial hearing. Optimal ADR induces an asymmetric information structure but makes the learning report-independent. It is ex ante fair and decreases the disputants’ expenditures, even if they fail to settle.We highlight the importance of real-world mediation techniques, such as caucusing, for implementing optimal ADR. Johannes Schneider gratefully acknowledges support from the Ministerio Economía y Competitividad (grant ECO2017-87769-P), and Comunidad de Madrid (grant MAD-ECON-POL-CM, H2019/HUM-5891). Funding for APC: Universidad Carlos III de Madrid (Read & Publish Agreement Wiley CRUE-CSIC 2021)

Herein we report a conceptually new non-decarboxylative electrolysis of carboxylic acids to obtain their corresponding anhydrides as highly valuable reagents in organic synthesis. All carbon atoms of the starting material are preserved in the product in an overall redox-neutral reaction. In a broad substrate scope of carboxylic acids the anhydrides are generated with high selectivity, which demonstrates the versatility of the developed method. Beneficially, no dehydrating reagents are required in comparison to conventional methods and the synthesis is based on uncritical starting materials using graphite and stainless steel as very inexpensive and eco-friendly electrode materials.

Psychological treatments are increasingly regarded as useful interventions for schizophrenia. However, a comprehensive evaluation of the available evidence is lacking and the benefit of psychological interventions for patients with current positive symptoms is still debated. The present study aimed to evaluate the efficacy, acceptability and tolerability of psychological treatments for positive symptoms of schizophrenia by applying a network meta-analysis approach, that can integrate direct and indirect comparisons. We searched EMBASE, MEDLINE, PsycINFO, PubMed, BIOSIS, Cochrane Library, World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov for randomized controlled trials of psychological treatments for positive symptoms of schizophrenia, published up to January 10, 2018. We included studies on adults with a diagnosis of schizophrenia or a related disorder presenting positive symptoms. The primary outcome was change in positive symptoms measured with validated rating scales. We included 53 randomized controlled trials of seven psychological interventions, for a total of 4,068 participants receiving the psychological treatment as add-on to antipsychotics. On average, patients were moderately ill at baseline. The network meta-analysis showed that cognitive behavioural therapy (40 studies) reduced positive symptoms more than inactive control (standardized mean difference, SMD=-0.29; 95% CI: -0.55 to -0.03), treatment as usual (SMD=-0.30; 95% CI: -0.45 to -0.14) and supportive therapy (SMD=-0.47; 95% CI: -0.91 to -0.03). Cognitive behavioural therapy was associated with a higher dropout rate compared with treatment as usual (risk ratio, RR=0.74; 95% CI: 0.58 to 0.95). Confidence in the estimates ranged from moderate to very low. The other treatments contributed to the network with a lower number of studies. Results were overall consistent in sensitivity analyses controlling for several factors, including the role of researchers' allegiance and blinding of outcome assessor. Cognitive behavior therapy seems to be effective on positive symptoms in moderately ill patients with schizophrenia, with effect sizes in the lower to medium range, depending on the control condition.

We investigated the adsorption of different free-base carboxyl-functionalized porphyrins, 5,10,15,20-tetrakis(4-carboxyphenyl)-21,23H-porphyrin (2H-TCPP) and 5(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin (2H-MCTPP), on MgO nanocubes combining IR, UV/Vis and photoluminescence emission spectroscopy. The thermal behavior of the films was monitored in-situ during annealing. Both porphyrins bind to the nanocubes via one and two acid groups respectively, yielding monolayer films consisting of tilted molecules. For 2H-TCPP, two acid groups remain free and give rise to a characteristic IR band. Self-assembly in a tilted adsorbate layer suppresses metalation at room temperature, in contrast to non-functionalized 2H-TPP, which adsorbs flat-lying. Upon heating, 2H-MCTPP undergoes full metalation at temperatures below 280 °C, whereas 2H-TCPP does not metalate at all. The hindered metalation reaction is attributed to the rigidity of the adsorbate film preventing complexation. Our results show that the properties of porphyrin films on oxides can be tuned in a wide range via the position and arrangement of carboxyl anchoring groups.

BACKGROUND: Many people with schizophrenia do not respond to an initially prescribed antipsychotic drug. In such cases, one treatment strategy could be to increase the antipsychotic dose; and another strategy could be to switch to a different antipsychotic drug. OBJECTIVES: To examine the efficacy of increasing the antipsychotic dose versus switching the antipsychotic drug in the treatment of non‐responsive people with schizophrenia. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (10 June 2014, 6 October 2015, and 30 March 2017). We examined references of all included studies for further trials. SELECTION CRITERIA: All relevant randomised controlled trials (RCTs) comparing increasing the antipsychotic dose versus switching to a different antipsychotic drug for people with schizophrenia who have not responded to their initial antipsychotic treatment. DATA COLLECTION AND ANALYSIS: At least two review authors independently extracted data. We analysed dichotomous data using relative risks (RR) and their 95% confidence intervals (CIs). We analysed continuous data using mean differences (MD) and their 95% CIs. We assessed risk of bias for included studies and used GRADE to create a 'Summary of findings' table. MAIN RESULTS: We include one RCT with relevant data on 29 participants in this review. The trial had a parallel design and was double‐blind, but blinding procedures were not described. The trial included people who were non‐responsive to fluphenazine 20 mg/day administered for 4 weeks. Participants were randomly assigned to continuing treatment with fluphenazine 20 mg/day, increasing the dose to fluphenazine 80 mg/day or switching to haloperidol 20 mg/day for four additional weeks. Data were reported only for 47 out of 58 initially randomised participants. The trial was published in 1993. The fact that only one RCT with a small sample size (N = 29) was included in the analysis limits the quality of the evidence. Overall, no clear difference was found between groups in terms of the three available outcomes: global state (number of participants with clinically relevant response (RR 1.63, 95% CI 0.17 to 15.99, very low quality evidence); general mental state (endpoint score, BPRS total) (MD 2.00, 95% CI −4.20 to 8.20, very low quality evidence); and negative symptoms (endpoint score, SANS) (MD 3.40, 95% CI −12.56 to 19.36). No data were reported for leaving the study early, adverse effects, time in hospital, quality of life, satisfaction with care and functioning. AUTHORS' CONCLUSIONS: There is extremely limited evidence and no clear conclusions can be drawn. There is an urgent need for further trials in order to determine the optimal treatment strategy for people with schizophrenia who do not respond to their initial antipsychotic treatment.

Background Many people with schizophrenia do not reach a satisfactory clinical response with a standard dose of an initially prescribed antipsychotic drug. In such cases, clinicians face the dilemma of increasing the antipsychotic dose in order to enhance antipsychotic efficacy. Objectives To examine the efficacy of increasing antipsychotic dose compared to keeping the same dose in the treatment of people with schizophrenia who have not responded (as defined in the individual studies) to an initial antipsychotic drug trial. We also examine the adverse effects associated with such a procedure. Search methods We searched the Cochrane Schizophrenia Group Trials Register (10 June 2014, 6 October 2015, and 30 March 2017). We examined references of all included studies for further trials. Selection criteria All relevant randomised controlled trials (RCTs), reporting useable data, comparing increasing the antipsychotic dose rather than maintaining the original dose for people with schizophrenia who do not respond to their initial antipsychotic treatment. Data collection and analysis At least two review authors independently extracted data . We analysed dichotomous data using relative risks (RR) and the 95% confidence intervals (CI). We analysed continuous data using mean differences (MD) and their 95% CI. We assessed risk of bias for included studies and used GRADE to create a 'Summary of findings' table. Main results Ten relevant RCTs with 675 participants are included in this review. All trials were double blind except one single blind. All studies had a run-in phase to confirm they did not respond to their initial antipsychotic treatment. The trials were published between 1980 and 2016. In most studies the methods of randomisation, allocation and blinding were poorly reported. In addition sample sizes were often small, limiting the overall quality of the evidence. Overall, no clear difference was found between groups in terms of the number of participants who showed clinically relevant response (RR 1.09, 95% CI 0.86 to 1.40, 9 RCTs, N = 533, low-quality evidence), or left the study early due to adverse effects (RR 1.63, 95% CI 0.52 to 5.07, very low quality evidence), or due to any reason (RR 1.30, 95% CI 0.89 to 1.90, 5 RCTs, N = 353, low-quality evidence). Similarly, no clear difference was found in general mental state as measured by PANSS total score change (MD -1.44, 95% CI -6.85 to 3.97, 3 RCTs, N = 258, very low quality evidence). At least one adverse effect was equivocal between groups (RR 0.91, 95% CI 0.55 to 1.50, 2 RCTs, N = 191, very low quality evidence). Data were not reported for time in hospital or quality-of-life outcomes. Finally, subgroup and sensitivity analyses did not show any effect on the primary outcome but these analyses were clearly underpowered. Authors' conclusions Current data do not show any clear differences between increasing or maintaining the antipsychotic dose for people with schizophrenia who do not respond to their initial antipsychotic treatment. Adverse effect reporting was limited and poor. There is an urgent need for further trials in order to determine the optional treatment strategy in such cases.

As the prevalence of sleep disorders is increasing, new methods for ambulatory sleep measurement are required. This paper presents electrodermal activity in different sleep stages and a sleep detection algorithm based on electrodermal activity. We analysed electrodermal activity and polysomnographic data of 43 healthy subjects and 48 patients with sleep disorders. Electrodermal activity was measured using an ambulatory device worn at the wrist. Two parameters to describe electrodermal activity were defined based on previous literature: EDASEF (electrodermal activity-smoothed feature) as parameter for skin conductance level; and EDAcounts (number of electrodermal activity-peaks) as skin conductance responses. Analysis of variance indicated significant EDASEF differences between the sleep stages wake versus N1, wake versus N2, wake versus slow-wave sleep, and wake versus rapid eye movement. The analysis of EDAcounts also showed significant differences, especially in the stages slow-wave sleep versus rapid eye movement. Between healthy subjects and patients, a significant disparity of EDAcounts was revealed in stage N1. Furthermore, the variances of EDASEF and EDAcounts in N1, N2 slow-wave sleep and rapid eye movement were higher in the patient group (p [F test] < .05). Next, an electrodermal activity-based sleep/wake discriminating algorithm was constructed. The optimized algorithm achieved an average sensitivity and specificity for sleep detection of 97% and 75%. The epoch agreement rate (average accuracy) was 86%. These outcomes are comparative to sleep detection algorithms based on actigraphy or heart rate variability. The results of this study indicate that electrodermal activity is not only a robust parameter for describing sleep, but also a potential suitable method for ambulatory sleep monitoring.

Silicon nitride (Si3N4) materials with preferentially aligned β-Si3N4 grains were tribologically characterized with respect to their possible application in a high-pressure gasoline pump. Tribological tests were performed under oscillating sliding conditions lubricated with isooctane as a substitute for gasoline using Si3N4 counterbodies. Performance in terms of wear of the aligned materials surpassed that of nonaligned reference Si3N4, as well as that of self-mated silicon carbide, zirconia, alumina, and a steel sliding pair. The plane perpendicular to the extruding direction and parallel to the hot-pressing axis was the most wear resistant.

International audience; We present vertically-resolved observations of aerosol composition during pristine summertime Arctic background conditions. The methansulfonic acid (MSA)-to-sulfate ratio peaked near the surface (mean 0.10), indicating a contribution from ocean-derived biogenic sulfur. Similarly, the organic aerosol (OA)-to-sulfate ratio increased towards the surface (mean 2.0). Both MSA-to-sulfate and OA-to-sulfate ratios were significantly correlated with FLEXPART-WRF-predicted airmass residence time over open water, indicating marine influenced OA. External mixing of sea salt aerosol from a larger number fraction of organic, sulfate and amine-containing particles, together with low wind speeds (median 4.7 m s−1), suggests a role for secondary organic aerosol formation. Cloud condensation nuclei concentrations were nearly constant (∼120 cm−3) when the OA fraction was −3 when the organic fraction was larger and residence times over open water were longer. Our observations illustrate the importance of marine-influenced OA under Arctic background conditions, which are likely to change as the Arctic transitions to larger areas of open water.

Biofilm formation in Bacillus subtilis requires the differentiation of a subpopulation of cells responsible for the production of the extracellular matrix that structures the biofilm. Differentiation of matrix-producing cells depends, among other factors, on the FloT and YqfA proteins. These proteins are present exclusively in functional membrane microdomains of B. subtilis and are homologous to the eukaryotic lipid raft-specific flotillin proteins. In the absence of FloT and YqfA, diverse proteins normally localized to the membrane microdomains of B. subtilis are not functional. Here we show that the absence of FloT and YqfA reduces the level of the septal-localized protease FtsH. The flotillin homologues FloT and YqfA are occasionally present at the midcell in exponentially growing cells and the absence of FloT and YqfA negatively affects FtsH concentration. Biochemical experiments indicate a direct interaction between FloT/YqfA and FtsH. Moreover, FtsH is essential for the differentiation of matrix producers and hence, biofilm formation. This molecular trigger of biofilm formation may therefore be used as a target for the design of new biofilm inhibitors. Accordingly, we show that the small protein SpoVM, known to bind to and inhibit FtsH activity, inhibits biofilm formation in B. subtilis and other distantly related bacteria.

In the search for materials that can withstand the new demanding tribological conditions, carbon nanotubes containing ceramic composites emerge as a promising alternative in gasoline direct injection systems. To explore this prospect, the tribological properties of dense good-dispersed multiwalled carbon nanotubes (MWCNTs) containing silicon nitride (Si3N4 )n anocomposites were investigated using a reciprocating ball-on-plate configuration mated against Si3N4 balls under lubrication with isooctane. The friction coefficient and the wear resistance of the materials were evaluated as a function of the MWCNTs content (up to 8.6 vol%) and the applied load (50–200 N). For the nanocomposites both the friction coefficient and the wear volume decreased in about 40% and 80%, respectively, as compared with the monolithic material. This enhanced tribological performance of the nanocomposites was attributed to the special role played by nanotubes, acting as solid lubricant and modifying, at the same time, the stress field distribution at the contact, thus notably enhancing the wear resistance at high loads.

Multidimensional spatially selective excitation (SSE) has stimulated a variety of useful applications in magnetic resonance imaging and magnetic resonance spectroscopy, which have regained considerable interest after the recent introduction of parallel excitation. For SSE, radiofrequency pulses are designed specifically for certain time-courses of spatially encoding magnetic fields (SEM) which are applied simultaneously with the radiofrequency pulses. However, experimental imperfections of gradient-systems and undesired SEM field contributions often prevent the correct co-action of radiofrequency pulses and gradient-waveforms and therefore degrade the fidelity of excitation patterns, especially for parallel excitation. To cope with such imperfections, a classical measurement of k-space-trajectories can be performed followed by an adaptation of the SSE-pulses. However, this method is limited to linear SEM field distributions, which are describable in the k-space-formalism. Hence, this work presents a more sophisticated method consisting in a spatially resolved measurement of the temporal phase evolution of the transverse magnetization. This exhaustive phase information can be incorporated into pulse-design algorithms to compensate even for undesired spatially nonlinear, dynamic SEM field contributions. Both approaches are assessed in various experimental scenarios and individual benefits and limitations are discussed. The adaptation of SSE-pulses to experimentally achieved calibration data turned out to be very beneficial, and especially the novel spatially resolved method exhibited high potential for robust SSE even in adverse experimental setups. Magn Reson Med, 2011. © 2010 Wiley-Liss, Inc.

With respect to the application in unlubricated friction systems like dry clutches a commercially available, slightly porous monolithic alumina was modified using laser irradiation by embedding TiN particles. The materials development was carried out by experimental studies and numerical simulation. Temperature and velocity profiles of the molten alumina and the dispersed TiN particles during laser processing were calculated using a finite volume program (PHOENICS). Tribological properties of the modified ceramics were characterized in unlubricated sliding contact with the grey cast iron GJL-250 and the steel 100Cr6 using a pin-on-disc tribometer. Frictional and wear behaviour were analysed at varied sliding speeds. Commercial alumina and silicon carbide ceramics were used as reference materials. The friction and wear behaviour were determined by mechanical interactions, mainly abrasive processes, material transfer and formation of surface layers from densified wear particles, combined with tribochemical reactions. Sliding pairs with the lasermodified multiphase ceramics showed a greater wear resistance and a greater constancy of the friction coefficient with increasing sliding speed compared to the commercial Al2O3 ceramic. TiN-partikelverstarkte Aluminiumoxid-Keramik fur ungeschmierte Friktionsanwendungen mit metallischen Gegenkorpern Durch einen lasergestutzten Prozess wurden TiN-Partikel verschiedener Grose in die Randschicht einer kommerziellen Aluminiumoxidkeramik eingebettet, um das Reibungs- und Verschleisverhalten gezielt zu beeinflussen. Aufgrund der komplexen Zusammenhange zwischen den Prozessparametern und der Mikrostruktur wurde der lasergestutzte Herstellungsprozess von numerischen Simulationsrechnungen begleitet, die eine Vorhersage der Prozessergebnisse ermoglichten und den experimentellen Aufwand reduzierten. Neben diesen lasermodifizierten Keramiken wurde je eine kommerzielle monolithische Al2O3- und eine SSiC-Keramik in einem Stift/Scheibe-Tribometer im einsinnigen ungeschmierten Gleitkontakt mit Grauguss GJL-250 bzw. dem Stahl 100Cr6 untersucht. Das Reibungs- und Verschleisverhalten wurde bei Variation der Gleitgeschwindigkeit ermittelt. Dabei erwiesen sich die mechanische Schadigung durch Bildung von Rissen und Verschleisteilchen, Materialubertrag zwischen Grund- und Gegenkorper mit der Entstehung von Deckschichten sowie tribochemische Reaktionen (Tribooxidation) als bestimmende Mechanismen. Bei den lasermodifizierten Keramiken wurde unabhangig vom gepaarten Gegenkorper ein geringerer Abfall der Reibungszahl mit zunehmender Gleitgeschwindigkeit gemessen als bei der monolithischen Al2O3-Referenzkeramik. Auch der an den metallischen Scheiben erzeugte lineare Verschleisbetrag war geringer.

Uber einen zweistufigen Laserprozess wurde eine Randschichtmodifizierung einer handelsublichen Al2O3-Keramik in einer Dicke von 200 - 400 μm durch Zugabe von TiN bzw. TiN und ZrO2 durchgefuhrt. Als Referenzkeramiken wurden je eine handelsubliche Al2O3- und SSiC-Keramik eingesetzt. Die tribologische Charakterisierung in einem Stift-Scheibe-Prufstand erfolgte im ungeschmierten, einsinnigen Gleitkontakt gegen GG25- und 100Cr6-Gegenkorper. Neben dem metallischen Gegenkorper wurden als Versuchsparameter die Gleitgeschwindigkeit und die relative Luftfeuchte von 20 % bis 80 % bei Raumtemperatur variiert. Alle Paarungen zeigten tendenzmasig einen abfallenden Wert der Reibungszahl mit zunehmender Gleitgeschwindigkeit, wobei die Paarungen mit den randschichtmodifizierten Oxidkeramiken eine bessere Reibungszahlkonstanz als die mit der monolithischen Al2O3-Keramik aufwiesen. Der volumetrische Verschleiskoeffizient der Paarungen mit den lasermodifizierten Keramiken war kleiner als der der Referenzpaarungen mit den monolithischen Keramiken Al2O3 bzw. SSiC. Ein Einfluss der relativen Luftfeuchte trat bis zu einer Gleitgeschwindigkeit von 4 m/s auf. Das Reibungs- und Verschleisverhalten wurde durch die Uberlagerung von mechanischen Wirkmechanismen, insbesondere abrasiver Prozesse, und tribochemischen Reaktionen bestimmt Ceramic/metal-friction pairs under unlubricated sliding in short time tests A slightly porous, commercially available alumina ceramic was surface modified up to 200 - 400 μm thickness by laser processing and adding of TiN or TiN and ZrO2 powder, respectively. Tribological tests were carried out on the modified ceramics and for reference also on both a commercial highly dense alumina und a silicon carbide ceramic using a pin-on-disc tribometer. The short time tests with respect to dry clutches were run in unlubricated sliding contact against grey cast iron GG25 and steel 100Cr6, respectively. In addition to the counterbodys the sliding speed was varied as well as the relative humidity of the surrounding air between 20 % and 80 % at room temperature. All tested pairs showed a tendency of decreasing friction coefficient with increasing sliding speed but the pairs with the multiphase structure of the modified oxid-ceramics displayed a better independence of the friction coefficient than the pairs with the commercial Al2O3 ceramic. The values of the volumetric wear coefficient of the pairs with the lasermodified multiphase ceramics were smaller than those of the reference pairs with SSiC and Al2O3, respectively. An effect of the relative humidity was measured up to sliding speeds of 4 m/s. The friction and wear behaviour were determined by mechanical interactions, mainly abrasive processes, combined with tribochemical reactions.

Die Herstellung von keramischen und metallischen Mikrokomponenten in Mittel- und Grosserie durch Mikro-Pulverspritzgiesen gefullter Formmassen mit abrasiven keramischen oder metallischen Partikeln stellt hohe Anforderungen an die Verschleisbestandigkeit der eingesetzten Formeinsatz-Werkzeuge. Im Rahmen dieser Forschungsarbeiten wurde daher das Verschleisverhalten verschiedener legierter und unlegierter Stahle, galvanisch abgeschiedenen Nickels sowie einer Messinglegierung in einem speziellen Einspritz-Modellprufstand unter Beanspruchung durch ZrO2-, Al2O3- und Stahl-Formmasse charakterisiert. Die geringsten Verschleisbetrage wurden dabei jeweils an Prufkorpern aus dem einphasigen Nickel ermittelt. Die mehrphasigen, hochlegierten Stahle zeigten im Vergleich zum Nickel bei Beanspruchung durch keramische Formmasse um einen Faktor von bis zu drei hohere Verschleisbetrage. Die Ergebnisse der Untersuchungen zeigten, dass neben den Eigenschaften der Formmasse (u. a. Anteil, Grose, Form und Harte der keramischen bzw. metallischen Partikel) insbesondere die Gefugehomogenitat und weniger die Harte das Verschleisverhalten der Formeinsatz-Materialien beeinflusste. Wear of Materials Used as Mould Inserts in Micro Powder Injection Moulding Large-scale production of ceramic and metallic micro components via micro powder injection moulding of filled feedstocks with abrasive ceramic or metallic particles requires mould inserts with a high wear resistance. Therefore, the wear behaviour of alloyed and unalloyed steels, electroplated nickel and brass CuZn37 was studied using a special laboratory tribometer simulating powder injection moulding with zirconia, alumina and steel feedstocks. Uniphase nickel showed highest wear resistance of all tested materials. During tests with ceramic feedstock wear of the multiphase, high alloyed steels was up to three times higher than that of nickel. These results indicate that in micro powder injection moulding wear behaviour can depend more on microstructural parameters like homogeneity than on hardness of the materials. The wear behaviour also was strongly influenced by the characteristics of the feedstock (e.g. amount, size, shape and hardness of ceramic or metallic particles).

Eine handelsubliche Aluminiumoxidkeramik wurde durch CO2-lasergestutztes Umschmelzen und Einlegieren von Hafniumoxid mit unterschiedlichen Anteilen an Yttriumoxid gezielt oberflachenmodifiziert. In Folge der Laserbehandlung entstanden bis zu 400 μm dicke Randschichten mit einem mehrphasigen Gefuge, das durch eine Al2O3-Matrix und eine feinlamellare, eutektische Reaktionsphase aus HfO2 und Al2O3 entlang der Kristallitgrenzen der Al2O3-Matrix gekennzeichnet war. Das tribologische Verhalten der legierten Keramik wurde im ungeschmierten, reversierenden Gleitkontakt in Paarung mit Al2O3-Kugeln bei Raumtemperatur und einer relativen Luftfeuchte von 50 % charakterisiert. Das Abrasivverschleisverhalten wurde unter furchender Beanspruchung durch SiC-Abrasivpartikel untersucht. Das Reibungs- und Verschleisverhalten der lasermodifizierten Keramik wurde sowohl durch den Anteil als auch die Zusammensetzung des Legierungszusatzes beeinflusst. Die Untersuchungen zeigten fur die randschichtmodifizierte Keramik im Vergleich zu einer kommerziell erhaltlichen Al2O3-Keramik bzw. Al2O3-ZrO2-Mischkeramik (ZTA) deutlich verbesserte tribologische Eigenschaften. Die Reibungszahl konnte verringert und der Verschleiswiderstand erhoht werden. Friction and wear of surface modified HfO2-toughened alumina in unlubricated sliding contact Surface alloying of commercially available alumina was carried out using infrared laser irradiation for remelting and alloying with hafnia containing various amounts of yttria. Laser assisted surface modification resulted in multiphase surface layers with a thickness up to 400 μm. The tribological behaviour of the modified ceramics was determined in a laboratory tribometer under unlubricated, oscillating sliding contact against alumina balls at room temperature and a relative humidity of 50 %. Abrasive wear was measured in contact with SiC abrasive grits using an abrasive wheel tester. Tribological performance of the surface modified ceramic was influenced both by the amount and composition of the alloying additions. The results show that friction coefficient was reduced and wear resistance was increased for the alloyed ceramic compared with commercially available monolithic alumina and zirconia toughened alumina (ZTA).alumina, hafnia, ZTA, surface modification, friction, wear

In Hinblick auf ihre Anwendung als Formeinsatzmaterialien fur das Mikro-Pulverspritzgiesen mit keramischer ZrO2-Formmasse wurden die Stahle X38CrMoV5-1 und C 45E sowie galvanisches Nickel und die Messinglegierung Cu63Zn37 in zwei Laborprufstanden bezuglich ihres Verschleisverhaltens charakterisiert. Unter Furchungsbeanspruchung in einem Reibradprufstand mit 220er Flint-Abrasivpapier zeigten die Stahle den hochsten Verschleiswiderstand, der mit abnehmender Harte von den Stahlen uber Nickel nach Messing abnahm. Die Verschleisuntersuchungen in einem Einspritz-Modellprufstand mit ZrO2-Formmasse bei Temperaturen von 170 bzw. 190°C ergaben unter abrasiv-erosiven Beanspruchungsbedingungen eine entgegengesetzte Tendenz. Hier wiesen die weicheren Materialien Nickel und Messing den hoheren Verschleiswiderstand gegenuber den Stahlen auf. Die vorgestellten Ergebnisse deuten darauf hin, dass unter den fur das Mikro-Pulverspritzgiesen gewahlten Beanspruchungsbedingungen das Verschleisverhalten der Formeinsatze weniger von der Harte als vielmehr von der Gefugehomogenitat sowie der Verformungs- und Verfestigungsfahigkeit der eingesetzten Werkstoffe bestimmt wird. Tribological studies on metallic materials used as mould inserts in micro powder injection moulding (microPIM) with zirconia feedstock Wear behaviour of steel X38CrMoV5-1 and C 45E, electroplated nickel and brass Cu63Zn37 used as mould inserts in micro powder injection moulding (microPIM) was studied in two different laboratory tribometers. Using an abrasive wheel test with 220 mesh flint the volumetric wear increased with decreasing hardness from steel to nickel and brass. Experiments using a laboratory tester simulating powder injection moulding with zirconia feedstock at 170 and 190°C showed contrary results. Volumetric wear of the softer materials nickel and brass was significantly lower than that of steel X38CrMoV5-1 and C 45E. The presented results indicate that in micro powder injection moulding wear behaviour can depend more on microstructural parameters like homogeneity or the ability of work-hardening and deformation but on hardness of the materials.

In einem Labor-Mikrotribometer wurden im System abgeplattete Kugel/Scheibe tribologische Untersuchungen unter einsinniger Gleitbeanspruchung an Selbst- und Fremdpaarungen der Werkstoffe TZP-ZrO2, Polyacetal (POM) und Stahl 17-4PH an Luft und unter Wasserschmierung durchgefuhrt. Neben den verschiedenen Werkstoffpaarungen wurden insbesondere an der ZrO2-Selbstpaarung der Einfluss der relativen Luftfeuchte bzw. von Wasserschmierung, der Flachenpressung und der Gleitgeschwindigkeit untersucht. Die Ergebnisse zeigen, dass ZrO2-Keramik im Hinblick auf die tribologischen Eigenschaften eine vorteilhafte Alternative fur hochbeanspruchte mikromechanische Bauteile besonders unter Wasserschmierung im Vergleich zu heute vielfach eingesetzten Polymerwerkstoffen darstellt. Auch ungeschmiert an Luft wies die ZrO2-Selbstpaarung geringere Werte der Reibung und des Verschleises als Stahl/Stahl-, POM/Stahl- oder POM/ZrO2-Paarungen auf. Schlagworte: Feinwerktechnik, Mikromechanische Bauteile, Gleitverschleis, Reibung, Wasserschmierung, Zirkonoxid, Polyacetal, Stahl 17-4 PH.

The aim of this study was to measure the concentration of creatine in Langendorff perfused rat hearts, both by quantitative 1H-MRS and by high-pressure liquid chromatography (HPLC). First, the relaxation times and other parameters affecting absolute quantification by MRS were determined. At 11.75 T, the relaxation times of myocardial creatine were T1 = 1.1 ± 0.29 sec (mean ± SD, n = 5) and T2 = 56.4 ± 6.2 ms (n = 9). In phantom experiments the MRS measurements gave accurate values for the known relative concentrations of the detected substances. In glucose-perfused rat hearts, the creatine concentration measured by HPLC was 14.2 ± 1.9 mmol/kg wet weight (n = 8), in good agreement with literature values. The 1H-MRS measurements, however, resulted in creatine concentrations of only approximately 60% of this value. The application of CHESS-pulses for water suppression led to a further 30% reduction of the creatine MRS signal. These results indicate a reduced 1H-NMR visibility of creatine in the myocardium, which suggests a compartmentation of myocardial creatine into various pools. Magn Reson Med 43:497–502, 2000. © 2000 Wiley-Liss, Inc.

Today the structures of civil and military aircrafts mostly are assembled of sheets of high strength aluminum alloys which are fastened to the internal structure. These joints cause considerable problems because they are exposed to corrosive and dynamic load. Especially this is the case when sheets and fasteners are manufactured of high strength materials. One example are sheets of the alloy AA 2024 T351 with fasteners of the titanium alloy Ti 6Al 4V. During the usual production procedure sheets are used, which were chromic acid anodized and primed with a 2-pack epoxy primer. During the assembly of the structure the countersinks were drilled, the fasteners inserted and the top coat applied. This production procedure has the cosequence that the countersinks usually are not coated. As a consequence the paint cracks around the fasteners during service, moisture, dirt and salt creep in and cause severe intergranular attack. The repair scheme applied in the military area up to now (removing the corrosion and re-application of the standard paint scheme consisting of a chromate-containing washprimer, a chromate-free 2-pack epoxy primer and a 1-pack acrylic top coat) was not very successful. For this reason a number of new coating systems for the countersink area and the fasteners were tested. In order to simulate the real world, a simultaneous dynamic and corrosive test method was chosen.

TiB2-ZrO2-Mischkeramiken wurden durch Heispressen hergestellt und mechanische sowie tribologische Eigenschaften in Abhangigkeit vom Volumenanteil und der Modifikation des zugegebenen ZrO2 bestimmt. Durch die Zugabe von ZrO2 konnte die zum Erreichen hoher Enddichten notwendige Prestemperatur auf 1500°C gesenkt und das Kornwachstum des TiB2 verhindert werden. Die Mischkeramiken wiesen gegenuber reiner TiB2-Keramik, bei einer reduzierten Harte, hohere Festigkeiten und Bruchzahigkeiten auf. Die tribologischen Untersuchungen wurden unter ungeschmierter, reversierender Gleitbeanspruchung in Paarung mit Al2O3-, Si3N4- und SiC-Gegenkorpern sowie unter Furchungsbeanspruchung durch SiC-Abrasivpartikel durchgefuhrt. Im Gleitkontakt zeigten die Mischkeramiken einen hohen Verschleiswiderstand, fuhrten jedoch zu einem starken Verschleis der keramischen Gegenkorper und hohen Reibungszahlen verglichen mit selbstgepaarten, monolithischen Al2O3- und ZrO2-Keramiken. Unter Furchungsbeanspruchung durch SiC-Abrasivpartikel lag der Verschleiswiderstand der TiB2-ZrO2-Keramiken um einen Faktor biszu 30 hoher als der monolithischer Al2O3-Keramik. Der Verschleiswiderstand der TiB2-ZrO2-Kermiken nahm mit abnehmendem ZrO2-Anteil zu und erreichte bei den mit teilstabilisiertem, tetragonalem ZrO2 hohere Werte als bei den mit unstabilisiertem, monoklinen ZrO2 hergestellten Mischkeramiken. Effect of ZrO2 addition on mechanical and tribological properties of TiB2-ZrO2-composites TiB2-ZrO2-composites were produced by hot-pressing in argon. The mechanical and tribological properties of the composites were investigated in relation to the amount and the type of the ZrO2 added. Addition of ZrO2 reduced the sintering temperature of the TiB2-ZrO2-composites and led to growth inhibition of the TiB2 phase. ZrO2 also increased the bending strength and fracture toughness of the composites. Tribological tests were carried out using laboratory tribometers under unlubricated oscillating sliding contact against Al2O3-, Si3N4- and SiC-counterbodies. Abrasive wear of the ceramics against 80 mesh SiC grits was studied by using an abrasive wheel test. During sliding contact the composites showed high wear resistance but caused extensive wear of the counterbodies and high friction coefficients compaired to self-mated monolithic Al2O3- and ZrO2-ceramics. Volumetric wear loss of the TiB2-ZrO2-composites due to abasive SiC grits was by a factor up to 30 lower than that of a commercial monolithic Al2O3. Wear resistance of the composites increased with decreasing amount of ZrO2 and was higher for the composites with addition of partially stabilized tetragonal ZrO2 than for those with addition of monoclinic ZrO2.

The extracellular domain of the human interleukin-6 (IL-6) receptor, comprising 339 amino acids following the signal peptide, has been expressed in baculovirus-infected insect cells (Sf158). When the soluble receptor secreted into the culture medium was purified by affinity chromatography, using IL-6 immobilized on Sepharose, 6 mg soluble receptor was isolated from 1 l conditioned medium of Sf158 suspension cultures. A molar absorption coefficient of 9.3 x 10(4) l.mol-1.cm-1 was calculated from the ultraviolet spectrum of the soluble IL-6 receptor. After SDS/PAGE and silver staining, an apparent molecular mass of 48 kDa was estimated for the purified protein. Deglycosylation with peptide N-glycosidase F resulted in an increase in electrophoretic mobility and a decrease in the apparent molecular mass from 48 kDa to about 41-44 kDa. As expected, the soluble human IL-6 receptor bound human 125I-labeled IL-6 with low affinity (Kd = 500 pM). Furthermore, the binding of soluble human IL-6 receptor to immobilized IL-6 was studied using real-time interaction analysis. The recombinant soluble receptor showed biological activity on HepG2 cells stably transfected with a cDNA coding for IL-6 (HepG2-IL-6 cells). Haptoglobin mRNA synthesis was induced by the soluble IL-6 receptor at concentrations as low as 10 ng/ml. Five monoclonal antibodies were generated. Two groups of antibodies were identified mapping to amino acids 1-67 and 68-143 of the soluble IL-6 receptor, respectively. The plasma clearance of soluble 125I-labeled IL-6 receptor in the absence and presence of IL-6 was studied in rats as a model system. The kinetics was biphasic. Soluble IL-6 receptor/IL-6 complexes were cleared more rapidly than the soluble receptor alone. Intravenously injected soluble 125I-labeled IL-6 receptor, as well as complexes with IL-6, rapidly accumulated in liver and to a lesser extent in skeletal muscle, skin and kidneys. Subsequently, the radioactivity appeared in the gut content.

Preparation d'un cation contenant une liaison Fe≡C prepare a partir d'un complexe carbene. Structure cristalline