Search

International transboundary aquifers provide important water supplies to over 150 countries. Long-term sustainability of these aquifers requires transboundary cooperation and yet only a select few ...

Genome-wide association studies (GWAS) in plants typically suffer from limited statistical power. An alternative to the logistical and cost challenge of increasing sample sizes is to gain power by meta-analysis using information from independent studies. We carried out GWAS for growth traits with six single-marker models and regional heritability mapping (RHM) in four Eucalyptus breeding populations independently and by Joint-GWAS, using gene and segment-based models, with data for 3373 individuals genotyped with a communal EUChip60KSNP platform. While single-single nucleotide polymorphism (SNP) GWAS hardly detected significant associations at high-stringency in each population, gene-based Joint-GWAS revealed nine genes significantly associated with tree height. Associations detected using single-SNP GWAS, RHM and Joint-GWAS set-based models explained on average 3-20% of the phenotypic variance. Whole-genome regression, conversely, captured 64-89% of the pedigree-based heritability in all populations. Several associations independently detected for the same SNPs in different populations provided unprecedented GWAS validation results in forest trees. Rare and common associations were discovered in eight genes involved in cell wall biosynthesis and lignification. With the increasing adoption of genomic prediction of complex phenotypes using shared SNPs and much larger tree breeding populations, Joint-GWAS approaches should provide increasing power to pinpoint discrete associations potentially useful toward tree breeding and molecular applications.

Thomas Borsch, Hilda Flores-Olvera, Silvia Zumaya, Kai Müller (2018): Pollen characters and DNA sequence data converge on a monophyletic genus Iresine (Amaranthaceae, Caryophyllales) and help to elucidate its species diversity. Taxon 67 (5): 944-976, DOI: https://doi.org/10.12705/675.7

Background: Osteonecrosis of the lunate, Kienbock's disease, can lead to fragmentation of the lunate, carpal collapse, and severe osteoarthritis. Since the etiology of Kienbock's disease is impaired circulation, a diagnostic method capable of assessing perfusion would be valuable. Recent studies have suggested that dynamic contrast-enhanced (DCE) MR examinations at 3 T can assess perfusion in healthy carpal bones. Purpose: To evaluate the use of DCE-MR for assessing perfusion in the lunate bone in patients with Kienbock's disease. Furthermore, to compare perfusion with histopathology with a focus on bone viability. Study Type: Prospective case–control study. Population: Fourteen patients with Kienbock's disease and a control group of 19 healthy subjects. Field Strength: 3 T with T1-weighted fat-saturated contrast-enhanced gradient echo series. Assessment: Features of the enhancement curves from the DCE-MR examinations, time to peak (TTP), maximum slope (MS), and maximum enhancement (ME) assessed by a radiologist. Six of 14 patients were surgerized with lunate excision, allowing comparison between features of the enhancement curves and histopathology. Statistical Tests: Mann–Whitney U-test. P < 0.05 was considered a statistically significant difference. Results: Patients with Kienbock's disease showed significantly higher and faster perfusion parameters compared with the control group, the mean value of the TTP in patients was 126.73 sec, in controls 189.79 sec (P = 0.024), ME in patients 173.55 AU, in controls 28.46 AU (P < 0.001), and MS in patients 5.04 AU, in controls 1.06 AU (P < 0.001). When compared with histopathology, increased perfusion was seen in areas of bone formation but also in necrosis. Areas of normal bone showed low perfusion. Data Conclusion: DCE-MRI at 3 T can diagnose altered perfusion in patients with Kienbock's disease. Increased perfusion cannot definitely be used as a marker of bone viability. Level of Evidence: 1. Technical Efficacy: Stage 3. J. Magn. Reson. Imaging 2018. (Less)

Die Wirtschaftlichkeit und Energieeffizienz von Prozessen in der Gasverflussigung hangt u. a. von den im Verdampfer erzielten Warmeubergangskoeffizienten ab. Hier werden Berechnungsmethoden fur den Einfluss von Oberflachenstrukturen auf den Warmeubergang beim Sieden diskutiert. Es wird eine theoretisch begrundete Berechnungsmethode entwickelt und eine fundierte Datenbasis fur die Auslegung von Verdampfern aufgestellt. Dafur werden neben Einzelrohren auch kleine Rohrbundel im Labormasstab untersucht und die Ergebnisse im Technikum des Industriepartners verifiziert. The cost and energy efficiency of gas liquefaction processes is mainly dependent on the heat exchange coefficients of the evaporator. Here, methods to calculate the influence of the surface structures on the boiling heat transfer are discussed. A theoretical method is developed as well as a well-founded data basis for the design of evaporators. Therefore, single tubes as well as tube bundles are investigated on laboratory scale. The results were verified in the technical center of industrial partners.

Purpose Zero echo time (ZTE) imaging is a robust and silent 3D radial technique suitable for direct MRI of tissues with very rapid transverse relaxation. Given its successful application on micro- and animal MRI systems, the purpose of this work is to enable and demonstrate ZTE imaging in humans using a whole-body magnet. Methods A commercial 7 T MRI scanner was complemented by rapid high-power transmit-receive switches, a custom-built spectrometer, and a proton-free detector coil. With this setup, transmit-receive switching is achieved within 1 µs, radiofrequency (RF) excitation is performed in 3 µs, and digital bandpass filtering takes 5.3 µs, resulting in an effective dead time of only 5 µs. Results ZTE imaging was performed at 250 and 500 kHz bandwidth with central k-space gaps of 1.2 and 2.5 Nyquist intervals and repetition times of 739 and 471 µs. The technique was applied for silent 3D imaging of the head and joints of human volunteers at an isotropic resolution down to 0.83 mm. A sound pressure level of 41 dB(A) was measured, which is a reduction of more than 40 dB(A) compared to gradient-switched MRI. Conclusion ZTE imaging in humans was demonstrated for the first time, enabled by dedicated, high-performing RF hardware. Magn Reson Med 70:328–332, 2013. © 2013 Wiley Periodicals, Inc.

PURPOSE: To investigate the normal enhancement patterns of the scaphoid, lunate, and capitate bones with dynamic contrast-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study was approved by the hospital's Ethics Committee. Nineteen volunteers (13 female, 6 male; mean age 38 years) were examined and all gave written consent. Perfusion was assessed at 3 Tesla using dynamic contrast-enhanced MRI. After two-dimensional (2D) motion correction of the data set, regions of interest were placed in the capitate, lunate, and distal and proximal pole of scaphoid bone and from the mean signal intensities (SI), the enhancement was computed. The four locations were compared for time to peak, delay time, maximum enhancement, and maximum slope using Friedman's two-way analysis of variance. RESULTS: Typical SI versus time curves revealed two components: a faster component with strong contrast enhancement and a slow component with prolonged enhancement. The mean value (standard deviation, SD) for maximum enhancement was 51 (33)% in the capitate, 54 (25)% in the lunate, 51 (34)% in the proximal pole and 51 (28)% in the distal pole of the scaphoid. The result of the Friedman test showed no significant difference (P < 0.05) in the perfusion variables between the capitate, lunate, and distal and proximal scaphoid bones. CONCLUSION: Assessment of perfusion in normal carpal bone using contrast-enhanced MRI is possible. Optimization of the method and understanding of the normal perfusion may allow evaluation of pathological conditions such as osteonecrosis. J. Magn. Reson. Imaging 2013;. © 2013 Wiley Periodicals, Inc. (Less)

Recent phylogenetic analyses revealed a grade with Ranunculales, Sabiales, Proteales, Trochodendrales, and Buxales as first branching eudicots, with the respective positions of Proteales and Sabiales still lacking statistical confidence. As previous analyses of conserved plastid genes remain inconclusive, we aimed to use and evaluate a representative set of plastid introns (group I: trnL; group II: petD, rpl16, trnK) and intergenic spacers (trnL-F, petB-petD, atpB-rbcL, rps3-rpl16) in comparison to the rapidly evolving matK and slowly evolving atpB and rbcL genes. Overall patterns of microstructural mutations converged across genomic regions, underscoring the existence of a general mutational pattern throughout the plastid genome. Phylogenetic signal differed strongly between functionally and structurally different genomic regions and was highest in matK, followed by spacers, then group II and group I introns. The more conserved atpB and rbcL coding regions showed distinctly lower phylogenetic information content. Parsimony, maximum likelihood, and Bayesian phylogenetic analyses based on the combined dataset of non-coding and rapidly evolving regions (>14 000 aligned characters) converged to a backbone topology of eudicots with Ranunculales branching first, a Proteales–Sabiales clade second, followed by Trochodendrales and Buxales. Gunnerales generally appeared as sister to all remaining core eudicots with maximum support. Our results show that a small number of intron and spacer sequences allow similar insights into phylogenetic relationships of eudicots compared to datasets of many combined genes. The non-coding proportion of the plastid genome thus can be considered an important information source for plastid phylogenomics.

Kelvin probe force microscopy (KPFM) is used to investigate the electrostatic force between a conductive probe and doped semiconductors. The observed frequency dependence of the probed KPFM bias is strongly related to sample-specific intrinsic local electric fields. Equilibrium drift and diffusion of excess charge carriers at low operation frequencies influence the characteristics of the asymmetric electric dipole in the surface region of the investigated semiconductors during the KPFM measurement. The sample-specific KPFM background signal does not influence the frequency-dependent lateral variation of the electrical signal. The KPFM bias probed on doped semiconductor nanostructures with high or small enough operation frequencies allows for quantitative dopant profiling or investigation of diffusion processes in internal electric fields, respectively.

Alignment of nucleotide and/or amino acid sequences is a fundamental component of sequence-based molecular phylogenetic studies. Here we examined how different alignment methods affect the phylogenetic trees that are inferred from the alignments. We used simulations to determine how alignment errors can lead to systematic biases that affect phylogenetic inference from those sequences. We compared four approaches to sequence alignment: progressive pairwise alignment, simultaneous multiple alignment of sequence fragments, local pairwise alignment and direct optimization. When taking into account branch support, implied alignments produced by direct optimization were found to show the most extreme behaviour (based on the alignment programs for which nearly equivalent alignment parameters could be set) in that they provided the strongest support for the correct tree in the simulations in which it was easy to resolve the correct tree and the strongest support for the incorrect tree in our long-branch-attraction simulations. When applied to alignment-sensitive process partitions with different histories, direct optimization showed the strongest mutual influence between the process partitions when they were aligned and phylogenetically analysed together, which makes detecting recombination more difficult. Simultaneous alignment performed well relative to direct optimization and progressive pairwise alignment across all simulations. Rather than relying upon methods that integrate alignment and tree search into a single step without accounting for alignment uncertainty, as with implied alignments, we suggest that simultaneous alignment using the similarity criterion, within the context of information available on biological processes and function, be applied whenever possible for sequence-based phylogenetic analyses.

Zusammenfassung Die Verwendungmoglichkeit heterologer, im Handel befindlicher Thrombokinasen zur Quickwert-Bestimmung beim Huhn wurde gepruft und mit homologer, selbsthergestellter Kukenhirn-Thrombokinase verglichen. Bestimmte heterologe Thrombokinasen sind mit Einschrankung zur Quickwert-Bestimmung, besonders bei ausgepragten plasmatischen Gerinnungsstorungen, geeignet. Homologe Thrombokinasen ermoglichen jedoch beim belasteten und normalen Huhn exaktere Quickwert-Bestimmungen. Summary Studies on thromboplastin estimation with homologous and heterologous thrombokinase in normal fowls and in birds on a diet deficient in vitamin K and birds treated with sulphonamides The possibility of using heterologous, commercially available thrombokinases for the Quick technique in the fowl was investigated and compared with the results obtained with homologous chick brain thrombokinase prepared by the author. Certain heterologous thrombokinases can be used under specified conditions for determining the Quick time, especially if there is considerable interference with the coagulation of the plasma. Homologous thrombokinases allow more exact determinations in the normal fowl and in birds in which coagulation has been influenced by sulphonamides. Resume Recherches concernant le temps de coagulation au moyen de thrombokinases homologues et heterologues sur des poules normales, des poules ayant recu une alimentation deficiente en vitamine K et des poules traitees aux sulfonamides Les auteurs ont etudie les possibilites d'utilisation de thrombokinases heterologues commerciales pour la determination du temps de Quick chez la poule et compare les resultats a ceux que donnerent des thrombokinases homologues preparees en laboratoire a partir du cerveau de Poulet. Certaines thrombokinase heterologues sont utilisables dans certaines conditions pour la determination du temps de Quick, surtout s'il existe des troubles importants de la coagulation plasmatique. Des thrombokinases homologues permettent cependant des determinations plus exactes chez la poule normale ou ayant subi un traitement susceptible d'influencer la coagulation. Resumen Estudios sobre la determinacion del tiempo de tromboplastina con tromboquinasas homologas y heterologas en gallinas normales, alimentadas con dietas carenciales en vitamina K y agobiadas por sulfonamidas Se examino la posibilidad de utilizacion de tromboquinasas heterologas, que se encuentran en el mercado, para determinar el valor de Quick en la gallina, comparandose con una tromboquinasa homologa de cerebro de pollo, de preparacion propia. Ciertas tromboquinasas heterologas resultan apropiadas, con salvedad de la determinacion del valor de Quick, sobre todo en marcados trastornos plasmaticos de coagulacion. Sin embargo, las tromboquinasas homologas permiten estatuir valores de Quick mas exactos en la gallina gravada o normal.

Summary. Cryptococcosis is an important cause of lymphocytic meningitis, especially but not necessarily in immunocompromised patients. We present the case of a 23-year-old man with a severe and rapid course of a cryptococcal meningo-encephalitis, which led to visual and hearing loss, psychotic illness and radiculopathy. There was no evidence of immunodeficiency. Treatment with amphotericin B and flucytosine led to improvement of the symptoms but did not eradicate the micro-organisms from the cerebrospinal fluid (CSF). Maintenance therapy with fluconazole was necessary and led to improvement of the CSF pathology. Zusammenfassung. Die Cryptococcose ist eine wichtige Ursache lymphozytarer Meningitiden, vor allem—aber nicht ausschlieslich—bei Patien—ten mit Immundefekt. Wir berichten uber den Fall eines 23 Jahre alten Mannes mit schwerem und raschem Verlauf einer Cyptococcus-Meningoenze-phalitis, die zu Verlust des Seh- und Horvermo-gens, psychotischen Symptomen und einer Radikulopathie fuhrte. Es ergab sich kein Anhalt fur einen Immundefekt. Die Behandlung mit Amphotericin B und Flucytosin fuhrte zu einer Besserung der klinischen Symptome, jedoch war der Erreger im Liquor noch monatelang nach-weisbar. Daher wurde eine Erhaltungstherapie mit Fluconazol angeschlossen, unter der sich die Liquorbefunde langsam besserten.

Redox changes within neurones are increasingly being implicated as an important causative agent in brain ageing and neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD) and Alzheimer's disease (AD). Cells have developed a number of defensive mechanisms to maintain intracellular redox homeostasis, including the glutathione (GSH) system and antioxidant enzymes. Here we examine the effects of N-acetyl-L-cysteine (NAC) on beta-amyloid (A beta) secretion and tau phosphorylation in SHSY5Y neuroblastoma cells after exposure to oxidative stress inducing/cytotoxic compounds (H(2)O(2), UV light and toxic A beta peptides). A beta and tau protein are hallmark molecules in the pathology of AD while the stress factors are implicated in the aetiology of AD. The results show that H(2)O(2), UV light, A beta 1-42 and toxic A beta 25-35, but not the inactive A beta 35-25, produce a significant induction of oxidative stress and cell cytotoxicity. The effects are reversed when cells are pre-treated with 30 mM NAC. Cells exposed to H(2)O(2), UV light and A beta 25-35, but not A beta 35-25, secrete significantly higher amounts of A beta 1-40 and A beta 1-42 into the culture medium. NAC pre-treatment increased the release of A beta 1-40 compared with controls and potentiated the release of both A beta 1-40 and A beta 1-42 in A beta 25-35-treated cells. Tau phosphorylation was markedly reduced by H(2)O(2) and UV light but increased by A beta 25-35. NAC strongly lowered phospho-tau levels in the presence or absence of stress treatment.

In a combination of experimental techniques including electrical probes, potentiometry, and charge transient spectroscopy (QTS), we develop concepts how to quantify the potential drops at the contacts, the mobility in the channel region, and the density of states of deep traps in pentacene OFETs. For OFETs grown from unpurified pentacene on pre-patterned Au bottom contacts, a comparison between potentiometry and two-dimensional device simulations determines an injection barrier of 0.73 eV at the source contact and a hole mobility of 0.014 cm2 V–1 s–1 in the pentacene channel. Temperature-dependent QTS data reveal a trap level at about 125 meV from the hole transport band, indicating a relatively high density of unintentional dopants and therefore a high background density of majority charge carriers. In OFETs grown from purified pentacene onto a SiO2 gate dielectric and Au top contacts evaporated onto the pentacene channel without breaking the vacuum, potentiometry reveals a nearly perfect alignment of the metal work function with the hole transport level in the organic layer. The much lower density of deep traps in these samples raises the hole mobility to the range 0.1–0.2 cm2 V–1 s–1. A further improvement of the hole mobility and the resulting device performance can be achieved by a chemical treatment of the gate oxide with n-octadecytrichlorosilane (OTS). (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

To maintain the fertility of stallion spermatozoa during cooled storage, extender media are added to semen. In this study, three semen extenders were compared: EquiPro which contains defined caseinates and whey proteins instead of dried skim milk. The extender is provided in dry form and dissolved in distilled water prior to use. EquiPro TM has the same composition as EquiPro but is provided in a sterilized ready-to-use liquid form. AndroMed-E contains soybean lecithin as protein source. Semen was collected from seven stallions. Ejaculates were divided into three aliquots, diluted with the different extenders and stored at 5°C for 4 days. Total motility, membrane integrity, average path velocity (VAP), curvilinear-velocity (VCL), straight-line velocity (VSL), distance average path (DAP), distance curved line (DCL) and distance straight line (DSL) were determined by computer-assisted analysis. Total motility decreased in all extenders during storage. The parameters VAP, VCL, VSL, DAP, DCL and DSL in semen diluted in EquiPro TM at most times and in semen diluted in AndroMed-E at some times were lower than in semen diluted in EquiPro (p < 0.05). Viability on days 0 and 4 was lowest in semen diluted in AndroMed-E (p < 0.05). Velocity decreased faster when semen had been diluted in the sterilized liquid extender EquiPro TM or in AndroMed-E compared with the dry formula of EquiPro. Therefore the liquid sterilized EquiPro despite no difference in its chemical composition differs from the dry, non-sterilized EquiPro extender. Heat sterilization apparently changes effects of the extender on spermatozoa.

In this work we present the result of an algorithm implementation for reverse nonequilibrium molecular dynamics simulation which allows the prediction of viscosity. A non physical momentum flux is imposed by dividing the simulation box into slabs and applying an exchange of the largest negative and positive velocities atoms between the first and central slabs respectively, as result a velocity gradient is produced. This technique has been successfully implemented for atomistic simulations using a molecular dynamics package YASP which works on analytical potential. However, our work focuses on the implementation of RNEMD method into a molecular dynamics code GMQ which works on numerical potential. The developed code provides a reliable tool to predict viscosities for coarse-grained models via RNEMD technique. The results for Lennard-Jones liquids are presented as well as their comparison for both molecular dynamics codes. Our results are also in good agreement with experimental data.

Nuclear holoploid genome sizes (C-values) have been estimated to vary about 800-fold in angiosperms, with the smallest established 1C-value of 157 Mbp recorded in Arabidopsis thaliana. In the highly specialized carnivorous family Lentibulariaceae now three taxa have been found that exhibit significantly lower values: Genlisea margaretae with 63 Mbp, G. aurea with 64 Mbp, and Utricularia gibba with 88 Mbp. The smallest mitotic anaphase chromatids in G. aurea have 2.1 Mbp and are thus of bacterial size (NB: E. coli has ca. 4 Mbp). Several Utricularia species range somewhat lower than A. thaliana or are similar in genome size. The highest 1C-value known from species of Lentibulariaceae was found in Genlisea hispidula with 1510 Mbp, and results in about 24-fold variation for Genlisea and the Lentibulariaceae. Taking into account these new measurements, genome size variation in angiosperms is now almost 2000-fold. Genlisea and Utricularia are plants with terminal positions in the phylogeny of the eudicots, so that the findings are relevant for the understanding of genome miniaturization. Moreover, the Genlisea-Utricularia clade exhibits one of the highest mutational rates in several genomic regions in angiosperms, what may be linked to specialized patterns of genome evolution. Ultrasmall genomes have not been found in Pinguicula, which is the sister group of the Genlisea-Utricularia clade, and which does not show accelerated mutational rates. C-values in Pinguicula varied only 1.7-fold from 487 to 829 Mbp.

Carnivorous plants have emerged as model systems for addressing many ecological and evolutionary questions, and since Lentibulariaceae comprise more than half of all known carnivorous species (325 spp.), they are of particular interest. Studies using various molecular markers have established that Lentibulariaceae and their three genera are monophyletic with Pinguicula being sister to a Genlisea-Utricularia-clade, while the closest relatives of the family remain uncertain. Character states of the carnivorous syndrome in related proto-carnivorous lamialean families apparently emerged independently. In Utricularia, the terrestrial habit has been reconstructed as plesiomorphic, and an extension of subgenus Polypompholyx is warranted. In the protozoan-attracting Genlisea, subgenus Tayloria is revealed as basal lineage. In Pinguicula, the six major lineages found reflect radiations in clearly defined geographic regions, whereas most previously recognized subgeneric taxa are non-monophyletic. Genlisea and Utricularia exhibit substitutional rates that rank among the highest in angiosperms for the molecular markers analyzed. One possible explanation for this lies in selective constraints on a wide range of genomic regions that may have been lowered due to the use of an alternative mode of acquiring nutrients.

The genus Pinguicula is one of the three genera of the carnivorous Lentibulariaceae, comprising approximately 80 species. Phylogeny inference using nucleotide sequences of the chloroplast gene matK and the trnK group II intron, as well as a set of 32 morphological characters revealed five well-supported, major lineages within the genus. These lineages largely reflect radiations in clearly defined geographic regions, whereas most previously recognized sections of the genus are shown to be para- or polyphyletic. A species-rich Mexican-Central American-Caribbean clade has the Eurasian P. alpina and an East Asian clade as successive sisters. All three are characterized by a production of flower buds on winter-resting plants, a specific corolla hair structure and a very large corolla lower central lobe. Another diverse clade is composed of species with primarily European distribution including the widespread type species P. vulgaris. For this clade, vegetative reproduction during dormancy is synapomorphic. Species native to SE North America and the South American Andes and a group of Mediterranean and NE Atlantic coast species together appear in a fifth well-supported clade, that is characterized by a tropical-type growth habit. It is the only clade that has reached temperate zones of the southern hemisphere.

Background: The normal left ventricle shows a systolic wringing motion with clockwise rotation at the base and counterclockwise rotation at the apex. Purpose: The aim of the present study was (1) to assess left ventricular (LV) contraction and relaxation in patients with chronic heart failure (CHF), and (2) to evaluate the effect of medical therapy on LV contraction–relaxation behavior. Methods: Magnetic resonance was used to examine LV motion by labeling specific LV regions in three planes (myocardial tagging). Twenty-three subjects were included, nine healthy controls and 14 CHF patients. Cardiac motion was determined from the deformation of a rectangular grid in a basal and apical plane. CHF patients were put on triple therapy with ACE-inhibitors, β-blockers and spironolactone. Follow-up examination (n=9) was performed after 6 months. Results: In controls, systolic rotation was −9.5±2° at the base and +3.3±1° at the apex. In CHF patients, rotation was reduced both at the base (−3.4±2°, P

Gegenwartig erfolgt die Bewertung der Leistungsfahigkeit von polymeren Gleitwerkstoffen mit Hilfe von pU-Diagrammen oder noch einfacher mittels zulassiger pU-Kennwerte. Diese Bewertungsparameter geben jedoch nur die Beanspruchungsgrenze der untersuchten Paarung auf der jeweils verwendeten Prufeinrichtung wieder. Ziel der Untersuchung war die Bereitstellung von praxisrelevanten Bewertungskriterien fur trockenlaufende Kunststoff/Stahl-Paarungen und zwar auf der Basis von Kennzahlen. Hierzu wurden zunachst, aufbauend auf einer Dimensionsanalyse problemrelavante Kennzahlen herausgearbeitet und anschliesend Versuche mit POM und glasfaserverstarktem PA6/6T auf einem Stift-Scheibe-Tribometer durchgefuhrt, aber auch Versuche auf Original-Gleitlagerprufstanden. Es werden Temperatur-, Verschleis- und Reibungszahlverlaufe dargestellt, und ein brauchbares Ausfallkriterium prasentiert. Es wird auserdem eine Vorgehensweise vorgestellt, die es ermoglicht, das Reibungsverhalten derartiger Paarungen anhand einer Kennzahlengleichung, die temperaturabhangige Materialkennwerte, Belastungs- und Geometriekenngrosen beinhaltet, vorherzubestimmen. Desweiteren wird eine Moglichkeit zur Verschleisberechnung auf energetischer Basis und die Ubertragbarkeit der Erkenntnisse auf reale Anwendungsfalle aufgezeigt.

Purpose To assess the diagnostic value of three-dimensional coronary magnetic resonance (MR) angiography with fat saturation and navigator echo in the setting of restenosis after percutaneous transluminal coronary angioplasty (PTCA). Materials and Methods Thirty consecutive patients who had PTCA and were referred for elective coronary reangiography underwent MR imaging and coronary angiography. The pulse sequence was a cardiac triggered, single-slab, three-dimensional, gradient-echo sequence, employing a spin-echo navigator echo measurement to track the variation of the diaphragm during the scan. The following segments of the coronary arteries were included in this prospective study: left main coronary artery, proximal and middle left anterior descending, proximal and middle left circumflex, proximal and middle right coronary artery, and intermediate branch, if present. The quality of the MR images was graded from 0 to 5. Results In total, 221 coronary artery segments could be identified. Mean image quality was 3.3. Overall accuracy for segments with an image quality of grade 2 or more was 90%. To achieve a positive predictive value >70% for a significant stenosis/restenosis, only segments with quality ≥3 could be assessed, whereas an acceptable negative predictive value could be achieved for nearly all segments. Conclusion Our preliminary data suggest that MR coronary angiography may be most helpful as a screening test in selected patients to exclude clinically relevant stenoses or to assess restenoses after PTCA or in patients in whose coronary angiography is relatively contraindicated. J. Magn. Reson. Imaging 2004;20:383–389. © 2004 Wiley-Liss, Inc.

Plastid matK gene sequences for 374 genera representing all angiosperm orders and 12 genera of gymnosperms were analyzed using parsimony (MP) and Bayesian inference (BI) approaches. Traditionally, slowly evolving genomic regions have been preferred for deep-level phylogenetic inference in angiosperms. The matK gene evolves approximately three times faster than the widely used plastid genes rbcL and atpB. The MP and BI trees are highly congruent. The robustness of the strict consensus tree supercedes all individual gene analyses and is comparable only to multigene-based phylogenies. Of the 385 nodes resolved, 79% are supported by high jackknife values, averaging 88%. Amborella is sister to the remaining angiosperms, followed by a grade of Nymphaeaceae and Austrobaileyales. Bayesian inference resolves Amborella + Nymphaeaceae as sister to the rest, but with weak (0.42) posterior probability. The MP analysis shows a trichotomy sister to the Austrobaileyales representing eumagnoliids, monocots + Chloranthales, and Ceratophyllum + eudicots. The matK gene produces the highest internal support yet for basal eudicots and, within core eudicots, resolves a crown group comprising Berberidopsidaceae/Aextoxicaceae, Santalales, and Caryophyllales + asterids. Moreover, matK sequences provide good resolution within many angiosperm orders. Combined analyses of matK and other rapidly evolving DNA regions with available multigene data sets have strong potential to enhance resolution and internal support in deep level angiosperm phylogenetics and provide additional insights into angiosperm evolution.

The tandemly arranged genes psbT, psbN, and psbH code for proteins of photosystem II and are located in the large single copy region (LSC) of the chloroplast genome, downstream of psbB. So far, most of the studies dealing with this region have been interested in the organization and transcription of the psbB operon, while less is known about the transcription of psbN or the phylogenetic utility of this region. In the current study we discuss a sigma70-type bacterial promoter motif upstream of psbN and present its consensus sequence for bryophytes. An analysis of the 3′ flanking inverted repeat sequences revealed a dyad symmetrical element, which is able to form a stable stem-loop structure. This hairpin structure is characterised for land plants, with an emphasis on bryophytes. Furthermore, we observed an inversion of up to 9 bases in the loop region of the hairpin structure, which occasionally occurred in different unrelated bryophyte families, orders and classes. Small inversions are frequently obscured in the alignment since, during automatic alignment, many gap-weighting schemes may not introduce gaps, nor does a manual insertion of gaps always seem needed at first glance. In subsequent phylogenetic analyses, minute inversion may overweight a particular mutation by interpreting the single inversion event as multiple apomorphic substitutions, which is particularly problematic since such inversion events are known to often be highly homoplastic. In the present study we use the psbT-N spacer as an example to quantify the effect of such small inversions, contrasting the phylogenetic structure obtained with and without information from the hairpin loop. We show that obscured minute inversions can highly significantly reduce the robustness of the phylogenetic hypothesis inferred from the data set.

Several unknown, abundant brominated compounds (BCs) were recently detected in the blubber of dolphins and other marine mammals from Queensland (northeast Australia). The BC were interpreted as potential natural products due to the lack of anthropogenic sources for these compounds. This study investigated whether some of the BCs accumulated by diverse marine mammal species are identical with natural BCs previously isolated from sponges (Dysidea sp.) living in the same habitat. Isolates from sponges and mollusks (Asteronotus cespitosus) were compared with the signals detected in the mammals' tissue. Mass spectra and gas chromatography retention times on four different capillary columns of the isolates from sponges and mammals were identical in all respects. This proves that the chemical name of the compound previously labeled BC-2 is 4,6-dibromo-2-(2'-dibromo)phenoxyanisole and that the chemical name of BC-11 is 3,5-dibromo-2-(3',5'-dibromo-2'-methoxy)phenoxyanisole. Using a quantitative reference solution of BC-2, we established that the concentrations of the brominated metabolies found in the marine mammals are frequently >1 mg/kg. The highest concentration (3.8 mg/kg), found in a sample of pygmy sperm whale (Kogia breviceps), indicates that BC-2 is a bioaccumulative, natural organohalogen compound. This is supported by the concentrations of the BCs in our samples being equal to the highest concentrations of anthropogenic BCs in any environmental sample. The quantitative determination of BC-2 in blubber of marine mammals from Africa and the Antarctic suggests that BC-2 is wide-spread. These results are direct proof that marine biota can produce persistent organic chemicals that accumulate to substantial concentrations in higher trophic organisms.

Background, aims: Between 4 and 8% of periodontitis patients are reported to respond poorly to conventional therapy. In these cases, adjunctive use of systemic antibiotics might be a reasonable therapeutic approach. The purpose of this study was to evaluate the effects of systemic amoxicillin/clavulanate as adjunct to periodontal surgery on the predominant subgingival microorganisms in patients not responding to mechanical therapy. Furthermore, the bacterial susceptibility to amoxicillin/clavulanate was analyzed before and after therapy in older to assess the clinical validity of pre-therapeutic susceptibility testing. Methods: In 10 periodontitis subjects with no subgingival detection of Actinobacillus actinomycetemcomitans, the predominant subgingival organisms were identified using the identification system Rapid ID 32 A as well as antibiotic susceptibility was tested utilizing the E test. Results: Porphyromonas gingivalis and Prevotella oralis were detected in 7/10 subjects and could no more recovered after therapy. Fusobacterium nucleatum and Peptostreptococcus micros were present in 5/10 patients before treatment, but could be detected in 6/10, resp. 3/10 after therapy. In 4/10 subjects harboring F. nucleatum and in 3/10 with P. micros, those organisms were not targeted by amoxicillin/clavulanate, although post-treatment testing revealed their alleged susceptibility (MICs varied from 0.023 to 0.032 mu g/ml, resp. from 0.125 to 2.0 mu g/ml). Conclusions: The results of this study suggest that the outcomes of conventional methods of susceptibility testing have to be interpreted very carefully when being used for treatment of plaque-related diseases. Furthermore, since the end point of systemic antibiotic treatment as adjunct to conventional therapy is elimination of F. nucleatum or P. micros in patients harboring these organisms, the use of amoxicillin/clavulanate appears not to be justified.

Zinc ricinoleate [Zn(Ri)2] is widely used in surfactant and detergent mixtures for the adsorption of odor-active compounds. The mechanism of this process is not known. In this initial study, we discuss the results of molecular dynamics computer simulations that were performed to get more information and detailed insights into the interaction mechanism between Zn(Ri)2 and odor-active substances. The calculations, based on simple molecular mechanics approximations, simulated the dynamic features of the molecular structures of Zn(Ri)2 in vacuum, in the oil phase, and in aqueous solution. We determined actual molecular conformations and simulated an adduct of ammonia with Zn(Ri)2. On close inspection, in the vacuum and oil phase structures, the Zn2+ ion is almost completely shielded by the oxygen ligands. Calculated structural transitions caused by the interaction of Zn(Ri)2 with water-solvent molecules resulted in a weakening of the electrostatic shield. Nucleophilic attack of odor-active compounds to the relatively unprotected Zn2+ atom is easy to achieve in aqueous solution. Simulation of the addition product of Zn(Ri)2 with ammonia revealed an elementary structural change, resulting in an increase of the solubility and adsorption activity of Zn(Ri)2. Molecular dynamics simulations showed that the results coincide with experimental observations.

The aza-Michael addition of enantiopure 1-aminopyrrolidines to (E)-alkenyl sulfones in the presence of a catalytic amount of ytterbium trifluoromethanesulfonate [Yb(OTf)3] yields β-hydrazino sulfones in moderate to good yields and with diastereoselectivities of up to ≥ 98%. The latter undergo reductive N-N bond cleavage with BH3 · THF and, after N-protection with Boc2O or benzyl bromide, afford N-protected β-amino sulfones with moderate to high enantiomeric excesses (ee = 42 to ≥96%) without racemization. Subsequent α-alkylation of the N,N-dibenzyl protected β-amino sulfones with various electrophiles yields α-alkyl-β-amino sulfones in excellent yields (88-97%) with high diastereomeric (de ≥96 to ≥98%) and enantiomeric purity (ee = 94 to ≥96%). The absolute configuration of the new stereogenic centre was determined by X-ray structural analysis and confirmed by NMR spectroscopy (NOE experiments). Possible reaction mechanisms for the conjugate addition and α-alkylation are presented.

The pesticide endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide) has been detected in rivers in the cotton (Gossypium hirsutum L.)-growing area of northern New South Wales at a 5 yr mean (1991-1995) concentration of 0.06 mu g L-1. One pathway by which endosulfan reaches the riverine environment is transport on contaminated dust. Our objectives were to examine: (i) dust deposition from vehicular traffic on an unsealed road on a cotton farm, and around a cotton field in the 11 to 65 h period after endosulfan application; (ii) endosulfan deposition in the 11 to 65 h period after endosulfan application, and over a 3-mo period at on-farm and off-farm (nontarget) locations. Dust deposition rates from vehicular traffic varied from 0.013 g m(-2) vehicle(-1) at 1 m distance, to 0.002 g m(-2) vehicle(-1) at 100 m distance from an unsealed road (soil surface, no gravel added). The maximum endosulfan deposition in the 11 to 65 h post-spraying period was 95 mu g m(-2) at 5 m from the field. Over a 3-mo monitoring period (December 1996-March 1997), the average daily deposition rate of endosulfan was 0.16 mu g m(-2) d(-1) for the off-farm sites compared with 0.35 mu g m(-2) d(-1) for the on-farm site. As the measurement period was one of the wettest on record and the number of endosulfan applications was less-than-normal, the dust and endosulfan deposition results may be interpreted as minima.

The purpose of this study was to investigate whether MR angiography (MRA) of the portal venous system may be improved by means of superparamagnetic iron oxides (SPIOs) during accumulation phase imaging and to study the underlying contrast mechanisms. MRA of the portal venous system was performed on 48 patients before and after intravenous injection of a new SPIO (Resovist, Schering AG, Berlin, Germany). Resovist, as a predominantly liver parenchymal darkening agent on T2-weighted MR images with uptake into the reticuloendothelial cell system, was administered intravenously by bolus injection of 8 to 12 micromol Fe/kg body weight. Patients were scanned with breath-hold coronal and axial two-dimensional (2D) time of flight (TOF) MRA (TR = 31.0 msec, TE = 9.8 msec, flip angle (FA) = 50 degrees, and 6.9-second acquisition time per section) sequences. Signal intensity values of liver parenchyma, the portal venous system, and background were obtained for quantitative analysis. The clinical relevance of additional plain and contrast-enhanced MRA studies for surgical planning was assessed by independent reading of three readers. Liver signal-to-noise ratio (SNR) significantly decreased following iv injection of Resovist; however, SNR values of the portal veins or hepatic veins did not change significantly. Visibility of the portal venous system improved significantly (tertiary branches visible: pre in 15.2% versus post in 87.0% of patients). Resovist-enhanced 2D-TOF MRA may improve planning of liver resections by better demonstrating the relationship of central liver lesions and vessels on source images. The decrease in liver SNR at a constant vessel SNR after iv injection of Resovist improves MRA of the liver. SPIO-enhanced 2D-TOF MRA scans are superior to plain 2D-TOF MRA studies and may be added for the workup of preoperative patients.

cDNA representational difference analysis (cDNA-RDA) is a polymerase-chain-reaction-coupled subtractive and kinetic enrichment procedure for the isolation of differentially expressed genes. In this study, the technique was used to isolate novel genes specifically expressed in pancreatic cancer. cDNA-RDA was done on cDNA reverse transcribed from a poly(A)+ mRNA pool made from 10 cancer tissues (tester) by using as a driver a cDNA from a poly(A)+ mRNA pool made from a combination of 10 tissues of chronic pancreatitis and 10 healthy pancreatic tissues. The use of chronic pancreatitis in addition to healthy pancreas mRNA in the driver preparation eliminated the influence of stromal tissue components present as contamination in the cancer-specific preparations. Such cDNA-RDA led to the isolation of 16 distinct, cancer-specific gene fragments. These were confirmed to be overexpressed in pancreatic cancer tissues by Northern blot analysis. Sequence analysis revealed homologies to five genes previously implicated in the carcinogenesis of the pancreas or other tissues. Eleven fragments had no significant homology to any known gene and thus represent novel candidate disease genes. The experiments demonstrate that cDNA-RDA is a reproducible and highly efficient method for the identification of novel genes with cancer-specific expression. Genes Chromosom. Cancer 19:97–103, 1997. © 1997 Wiley-Liss, Inc.

— Constant amplitude fatigue tests with welded specimens under fully reversed four-point bending as well as under axial loading have shown that vibration stress relieving does not lead to a fatigue life improvement of welded parts when compared to the as-welded state. Thus, a substitution of thermal stress relieving by a vibration treatment is not successful. This was also proved by residual stress measurements in the welded parts studied in this paper.

treegraph assists in producing complex ready-to-publish figures of phylogenetic trees. The TGF format used by the program automates formatting of several different statistical support value types (confidence estimates) per tree node. Moreover, internal text and graphical labels are automatically arranged at the nodes as are annotations for clades or groups of terminals. TREEGRAPH imports NEXUS trees and related file formats. Beyond common tree edit operations, simultaneous pruning of subtrees (simplification of the tree to higher order clades) and saving of subtrees is possible. TREEGRAPH exports to the standard vector graphics formats Scalable Vector Graphics and PostScript.

Pancreatic cancer shows a strong desmoplastic reaction characterized by a remarkable proliferation of interstitial connective tissue (collagens type I and III, fibronectin). In this study we have analyzed the balance of expression of mRNAs encoding extracellular matrix components (collagens I, III and IV, laminin, fibronectin), extracellular matrix-degrading metalloproteinases (MMP-1,-2,-3 and-9) and tissue inhibitors of metalloproteinases (TIMP-1 and-2) in pancreatic cancer and control pancreatic tissue by Northern-blot analysis and mRNA in situ hybridization. Transcripts for MMP-1 (interstitial collagenase) and MMP-3 (stromelysin-1) were not detectable in pancreatic cancer and control tissues. Steady-state levels of transcripts encoding extracellular matrix proteins, MMP-2 (72-kDa collagenase IV), MMP-9 (92-kDa collagenase type IV), TIMP-1 and TIMP-2 were elevated in the majority of pancreatic-cancer tissue samples as compared to control pancreatic tissue. A good correlation was seen between overexpression of these MMPs and TIMPs and the steady-state levels of transcripts coding for extracellular matrix proteins, the amount of collagen protein and the severity of the desmoplastic reaction. In situ hybridization studies localized transcripts coding for collagens type I and III to spindle-shaped stromal cells, whereas transcripts for MMP-2, MMP-9, TIMP-1 and TIMP-2 were found in both stromal and tumor cells. However, MMP-2 transcripts appeared to be more abundant in stromal cells, TIMP-1 and TIMP-2 transcripts were evenly distributed over tumor and stromal cells and relatively more MMP-9 transcripts were found in tumor cells. We conclude that, in human pancreatic cancer, MMP-2, MMP-9, TIMP-1 and TIMP-2 may be involved in processes leading to the strong desmoplastic reaction observed in these tumors. Both stromal and tumor cells appear to be the source of MMPs and TIMPs in human pancreatic cancer. © 1995 Wiley-Liss, Inc.

In the present study, a total of 619 subgingival and extracrevicular samples from 66 early-onset periodontitis, 42 adult periodontitis/gingivitis and 36 treated Actinobacillus actinomycetemcomitans-associated periodontitis patients were selectively cultivated for presence of A. actinomycetemcomitans. The organism was recovered from 68% cases with early-onset periodontitis, 24% cases with adult periodontitis/gingivitis and 50% of treated patients. Associations between recovery from pooled subgingival plaque and samples from extracrevicular locations as well as between different extracrevicular samples, were not heterogeneous with regard to different groups with the exception for cheek/saliva comparisons (odds ratios: early-onset periodontitis 825; adult periodontitis 8.1; treated patients 117; 0.05

Synthesis of extracellular matrix components is enhanced in the rat pancreas during regeneration from caerulein-induced pancreatitis. To study the involvement of transforming growth factor beta 1 (TGF beta 1), one of the most potent modulators of the extracellular matrix, in the process of pancreatic regeneration we examined the expression of this gene on the transcript and protein level. Pancreatic RNA was extracted from rats killed 0 h, 12 h, 24 h, 2, 3 and 7 days after induction of caerulein pancreatitis. Transcript levels for TGF beta 1 were measured by slot-blot analysis and mRNA in situ hybridization. Total amount of TGF beta 1-protein was measured using a radioligand binding assay. TGF beta 1 protein was increased twofold after 24 h and 48 h and returned to control values 7 days after induction of pancreatitis, TGF beta 1-mRNA reached maximal values (3-fold over controls) after 2 days. The largest amount of TGF beta 1-mRNA was found in pancreatic acinar cells and in stromal cells. In summary, expression of TGF beta 1 in acinar and stromal cells of the rat pancreas is enhanced during regeneration from caerulein-induced pancreatitis, which may indicate an involvement of TGF beta 1 in the regulation of extracellular matrix regeneration in the rat pancreas after caerulein-induced pancreatitis.