823 research outputs found
Wood-ash recycling affects forest soil and tree fine-root chemistry and reverses soil acidification
Wood ash was applied to a forest ecosystem with the aim to recycle nutrients taken from the forest and to mitigate the negative effects of intensive harvesting. After two years, the application of 8,000 kg ha−1 of wood ash increased soil exchangeable Ca and Mg. Similarly, an increase in Ca and Mg in the Norway spruce fine roots was recorded, leading to significant linear correlations between soil and root Ca and soil and root Mg. In contrast to these macronutrients, the micronutrients Fe and Zn and the toxic element Al decreased in the soil exchangeable fraction with the addition of wood ash, but not in the fine roots. Only Mn decreased in soil and in fine roots leading to a significant linear correlation between soil and root Mn. In soil, as well as in fine roots, strong positive correlations were found between the elements Ca and Mg and between Fe and Al. This indicates that the uptake of Mg resembles that of Ca and that of Al that of Fe. With the wood ash application, the pH increased from 3.2 to 4.8, the base saturation from 30% to 86%, the molar basic cations/Al ratio (BC/Al) of the soil solution from 1.5 to 5.5, and the molar Ca/Al ratio of the fine roots from 1.3 to 3.7. Overall, all below-ground indicators of soil acidification responded positively to the wood ash application within two years. Nitrate concentrations increased only slightly in the soil solution at a soil depth of 75-80 cm, and no signs of increased heavy metal concentrations in the soils or in the fine roots were apparent. This suggests that the recycling of wood ash could be an integral part of sustainable forest management because it closes the nutrient cycle and reverses soil acidificatio
Osteosynthese distaler Radiusfrakturen mit der AO/ASIF Titan-Pi-Platte
Zusammenfassung: Die AO/ASIF Titan-Pi-Platte wurde entwickelt, um eine optimale Versorgung distaler, intraartikulärer und instabiler Radiusfrakturen zu gewährleisten. Dies soll durch eine optimale Anpassung an die Anatomie sowie durch Winkelstabilität und flachem Design erfolgen. Ziel der vorliegenden retrospektiven Fallkontrollstudie war es, die objektiven und subjektiven Resultate anhand einer konsekutiven Reihe von 61Patienten mindestens 12Monate (12-29Monate) postoperativ mittels Befragung, klinischer Untersuchung und konventioneller radiologischer Bildgebung zu erheben. Nach Klassifikation der AO handelte es sich um 3A2-, 23A3-, 1B1-, 12C1- und 22C2-Frakturen. Die Resultate zeigen insgesamt ein gutes bis sehr gutes Resultat bezüglich des subjektiven Befindens. Die Messungen des Bewegungsumfangs ergaben durchschnittlich über 80% im Vergleich zur Gegenseite. Die klinische Prüfung der Extensorensehnen ergab keine Rupturen und 18% Irritationen. Das Kollektiv mit Osteosynthesematerialentfernung zeigte einen signifikant größeren Bewegungsumfang der Extension und Ulnarabduktion, eine höhere Kraft sowie nur 3,8% Sehnenirritationen. Mit der Pi-Platte lassen sich gute subjektive und objektive Resultate erreichen. Aufgrund der signifikant besseren Beweglichkeit und höheren Kraft sowie der geringeren Rate an Sehnenirritationen nach Entfernung der Platte sollte die Indikation zur Osteosynthesematerialentfernung großzügig gestellt werde
Local Epitaxial Overgrowth for Stacked Complementary MOS Transistor Pairs
A three-dimensional silicon processing technology for CMOS circuits was developed and characterized. The first fully depleted SOI devices with individually biasable gates on both sides of the silicon film were realized. A vertically stacked CMOS Inverter built by lateral overgrowth was reported for the first time. Nucleation-free epitaxial lateral overgrowth of silicon over thin oxides was developed for both a pancake and a barrel-type epitaxy reactor: This process was optimized to limit damage to gate oxides and minimize dopant diffusion within the Substrate. Autodoping from impurities of the MOS transistors built in the substrate was greatly reduced. A planarisation technique was developed to reduce the silicon film thickness from 13μm to below 0.5μm for full depletion. Chemo-mechanical polishing was modified to yield an automatic etch stop with the corresponding control and uniformity of the silicon film. The resulting wafer topography is more planar than in a conventional substrate CMOS process. PMOS transistors which match the current drive of bulk NM0S devices of equal geometry were characterized, despite the three-times lower hole mobility. Devices realized in the substrate, at the bottom and on top of the SOI film were essentially indistinguishable from bulk devices. A novel device with two insulated gates controlling the same channel was characterized. Inverters were realized both as joint-gate configuration and with symmetric performance of n- and p-channel. These circuits were realized in the area of a single NMOS transistor
The evolution of pebble size and shape in space and time
We propose a mathematical model which suggests that the two main geological
observations about shingle beaches, i.e. the emergence of predominant pebble
size ratios and strong segregation by size are interrelated. Our model is a
based on a system of ODEs called the box equations, describing the evolution of
pebble ratios. We derive these ODEs as a heuristic approximation of Bloore's
PDE describing collisional abrasion. While representing a radical
simplification of the latter, our system admits the inclusion of additional
terms related to frictional abrasion. We show that nontrivial attractors
(corresponding to predominant pebble size ratios) only exist in the presence of
friction. By interpreting our equations as a Markov process, we illustrate by
direct simulation that these attractors may only stabilized by the ongoing
segregation process.Comment: 22 pages, 8 figure
The anterior center edge angle in Lequesne's false profile view: interrater correlation, dependence on pelvic tilt and correlation to anterior acetabular coverage in the sagital plane. A cadaver study
Introduction: Lequesne's vertical-center-anterior margin (VCA) angle measured on the false profile view of the pelvis aims at quantifying the anterior acetabular coverage of the femoral head. The anterior delimitation of the acetabular roof is often defined on the false profile view but there are no data on its interrater reliability. Additionally, it is not known how pelvic tilt may influence this angle. Finally, the plane in which this angle is measured lies at an angle of 65° to the sagittal plane and we wondered if this angle would be transposable to the anterior acetabular coverage measured in the sagittal plane. Methods: Eight hips from four cadaver pelvises were investigated by means of a total of 72 false profile views, each taken in defined pelvic inclinations at 5° increments ranging from −20° to +20°, and the VCA angle measured by three independent raters. A computed tomography (CT) of each hip was performed in a neutral pelvic tilt position and a sagittal 2D reconstruction calculated in order to measure anterior coverage in the sagittal plane. The interrater reliability of the VCA angles was assessed using the intra-class correlation coefficient (ICC). The dependence of the VCA angle on pelvic tilt was assessed by regression analysis. The Correlation between the VCA angle and anterior coverage in the sagittal plane of the CT was analyzed using a simple linear regression model. Results: The interrater reliability for measurements of the VCA angle was almost perfect (ICC:0.97). Regression analysis showed that each degree of pelvic tilt was accompanied by a change of the VCA angle by a value of 0.63° (P<0.001). A low correlation between the VCA angle measured in the false profile view and the anterior coverage in the sagittal plane was statistically not significant (r=0.667, P=0.06). Conclusions: Lequesne's VCA angle has an excellent interrater reliability and represents a reliable measure of acetabular dysplasia for comparisons with published data. Lequesne's VCA angle is influenced by pelvic tilt in a linear manner. Performing the false profile view in a standing position may reduce the clinical relevance of this dependency on pelvic tilt. The correlation of Lequesne's VCA angle to anterior acetabular coverage in the sagittal plane is low and therefore unsuitable to be transposed into the sagittal plan
Komplexe proximale Humerusfraktur beim alten Menschen: Winkelstabile Plattenosteosynthese vs. Hemiarthroplastik
Zusammenfassung: Hintergrund: Ziel der vorliegenden Untersuchung ist ein direkter Vergleich der Schulterhemiarthroplastik (SHA) mit der winkelstabilen Plattenosteosynthese (WSPOS) beim alten Patienten mit komplexer proximaler Humerusfraktur. Patienten und Methoden: Zwischen 2003 und 2005 wurden alle Patienten (n=52, Alter ≥70Jahre) mit 3- und 4-Segment-Frakturen des proximalen Humerus, welche mit einer WSPOS (PHILOS®) versorgt wurden, prospektiv erfasst und nach einem Jahr mittels Constant-Score (CS), Oxford Shoulder Score (OSS) und radiologisch nachkontrolliert. Verglichen wurde die WSPOS mit einem historischen Kollektiv mit identischen Einschlusskriterien, welches zwischen 1995 und 1997 an der gleichen Institution mittels SHA versorgt wurde (n=59). Ergebnisse: Beide Patientenkollektive zeigten keine Unterschiede bezüglich Alter, Geschlechterverteilung und Frakturtypen. Der CS war signifikant besser für die WSPOS (median 71 vs. 41). Bezüglich Schmerzen zeigte sich im OSS kein Unterschied zwischen den Gruppen. In der WSPOS-Gruppe mussten signifikant mehr Revisionseingriffe durchgeführt werden (25% vs. 2%). Schlussfolgerung: Die WSPOS liefert beim alten Patienten, bei komplexen proximalen Humerusfrakturen deutlich bessere funktionelle Resultate, ist jedoch mit mehr Rezidiveingriffen behaftet. Die Selbständigkeit der Patienten kann bei beiden Operationsmethoden bei guter Schmerzfreiheit meist erhalten werde
Effect of bisacodyl on postoperative bowel motility in elective colorectal surgery: a prospective, randomized trial
Background: Postoperative ileus is a common condition after abdominal surgery. Many prokinetic drugs have been evaluated including osmotic laxatives. The data on colon-stimulating laxatives are scarce. This prospective, randomized, double-blind trial investigates the effect of the colon-stimulating laxative bisacodyl on postoperative ileus in elective colorectal resections. Materials and methods: Between November 2004 and February 2007, 200 consecutive patients were randomly assigned to receive either bisacodyl or placebo. Primary endpoint was time to gastrointestinal recovery (mean time to first flatus passed, first defecation, and first solid food tolerated; GI-3). Secondary endpoints were incidence and duration of nasogastric tube reinsertion, incidence of vomiting, length of hospital stay, and visual analogue scores for pain, cramps, and nausea. Results: One hundred sixty-nine patients were analyzed, and 31 patients discontinued the study. Groups were comparable in baseline demographics. Time to GI-3 was significantly shorter in the bisacodyl group (3.0 versus 3.7days, P = 0.007). Of the single parameters defining GI-3, there was a 1-day difference in time to defecation in favor to the bisacodyl group (3.0 versus 4.0days, P = 0.001), whereas no significant difference in time to first flatus or tolerance of solid food was seen. No significant difference in the secondary endpoints was seen. Morbidity and mortality did not differ between groups. Conclusion: Bisacodyl accelerated gastrointestinal recovery and might be considered as part of multimodal recovery programs after colorectal surger
Holographic Superconductors with Lifshitz Scaling
Black holes in asymptotically Lifshitz spacetime provide a window onto finite
temperature effects in strongly coupled Lifshitz models. We add a Maxwell gauge
field and charged matter to a recently proposed gravity dual of 2+1 dimensional
Lifshitz theory. This gives rise to charged black holes with scalar hair, which
correspond to the superconducting phase of holographic superconductors with z >
1 Lifshitz scaling. Along the way we analyze the global geometry of static,
asymptotically Lifshitz black holes at arbitrary critical exponent z > 1. In
all known exact solutions there is a null curvature singularity in the black
hole region, and, by a general argument, the same applies to generic Lifshitz
black holes.Comment: 23 pages, 4 figures; v2: added references; v3: matches published
versio
Lutte contre Gloeosporium (album et perennans) des pommes biologiques Post-Recolte avec des produits oxidants et des eaux électrolytiques,et Pre-Recolte avec differents produits biologiques entre 2001-2004
Dans la production biologiques des pommes les pertes post-récolte causées par Gloeospo-rium album et perennans peuvent atteindre, avec des variétés sensibles comme Pinova, Topaz ou GoldRush jusqu'à 80 %.
Il est connue que la thermothérapie (plonger les pommes pendant 2-3 min. dans l’eau chaude de 50-52 deg.) peut supprimer bien le développement du pathogène relativement bien. Les désavantages de la thermothérapie sont sa consommation d’énergie significative, ses hautes coûts d’investissement et finalement que les dégât latentes de G. album prove-nant du champ deviennent visible peu de jours après le traitement ce qui pouvait dévaloriser jusqu’à 30 % de la récolte.
Le but de nos études c’est de trouver des méthodes de lutte contre Gloeosporium album et perennans comme alternative à la thermothérapie.
Dans nos essays sur plusieurs années avec les variétés Pinova et Topas ni les produits oxi-dants (Jet5, H2O2, Nitrit, thé vert, thé de prèle ) ni l’ozone mis à l’eau (froid, 17 deg.) ont ap-porté des résultats régulièrement satisfaisants (pas de différence comparé avec les pommes non traitées). Les pertes ont atteint 60-80% après conservation et justqu’à 90 % après 10 jours de shelf-life de plus.
A partir de 2004 nous avons aussi testé des eaux électrolytiques (Anostel® et Cathostel®), une technique de désinfection qui vient surtout du secteur médicinal. Elle est propre, sans formation des résidus dans les produit ou dans l’environnement. En plongeant les pommes sériellement dans ces solutions pendant 5 min. chaque, l’efficacité n’était pas aussi bonne qu’avec thermothérapie (75 % vendable après conservations) mais beaucoup meilleur (62 % vendable) qu’avec tout les autres oxidants (48 % vendable). C’est pourquoi nous essayons d’optimiser la méthode des eaux électrolytiques avec des essaies en cours de cette année.
Car l’attaque des Gloeosporium sur champ peut avoir un effet tellement nocif malgré des traitements post récolte, nous avons aussi testé des stratégie de contrôle pre-récolte à partir du mois de Juillet avec des produits antagoniste (la levure Aureobasidium pullulans), KBV-Lactopéroxidase, Calcium-polysulphurique, cuivre, Calcium-Chloride (pour fortifier la cuti-cule) et Mycosin (argile acidifié).
De tout les produits testés pre-récolte seulement le Mycosin donnait des résultat satisfaisant, comparable à la thermothérapie. Aussi nous avons pu prouvé qu’avec Pinova le savon de coco pour lutter contre la maladie de suie (Cocana) à un effet significativement aggravant l’incidence de Gloeosporium.
Le but de nos études actuels c’est de développer des stratégies combiné pre- et post récolte (sans thermothérapie) qui n’interfèrent pas avec la lutte contre les autre maladies (suie, ta-velure, oidium) et qui se complémentent d’une façon idéale et écologique
A promising new device for the prevention of parastomal hernia.
Parastomal hernia (PSH) is the most frequent long-term stoma complication with serious negative effects on quality of life. Surgical revision is often required and has a substantial morbidity and recurrence rate. The development of PSH requires revisional surgery with a substantial perioperative morbidity and high failure rate in the long-term follow-up. Prophylactic parastomal mesh insertion during stoma creation has the potential to reduce the rate of PSH, but carries the risk of early and late mesh-related complications such as infection, fibrosis, mesh shrinkage, and/or bowel erosion. We developed a new stomaplasty ring (KORING), which is easy to implant, avoids potential mesh-related complications, and has a high potential of long-term prevention of PSH. Here we describe the technique and the first use
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