Color Doppler echocardiography does not provide adequate information about the severity of mitral regurgitation in patients with eccentric mitral regurgitation. We have developed a new procedure for ...3-dimensional (3D) color Doppler reconstruction and for segmentation of regurgitant jets. The volume of regurgitant jets was compared with jet area in 63 patients with mitral regurgitation. Mitral regurgitation was assessed by angiography, regurgitant fraction and volume by pulsed Doppler, JA by planimetry, and JV by 3-dimensional Doppler. Twenty-eight patients with central jets were compared with 35 patients with eccentric jets. In the patients with eccentric jets, JV showed significant correlations with regurgitant volume (r = 0.90; P <.01) and regurgitant fraction (r = 0.76; P < .01) and was able to separate groups with different degrees of mitral regurgitation (P <.01). Three-dimensional Doppler revealed origin, direction, and spatial spreading of complex jet geometry. JV, a new parameter of mitral regurgitation, was also capable of quantifying asymmetrical jets.
The biosynthesis of chrysomelidial and plagiodial was studied in the rove beetle subtribe Philonthina (Staphylinidae). Glandular homogenates were found to convert synthetic (2
E,6
...E)–trideuteromethyl–5,5–
2H
5octa–2,6–diene–1,8–diol (
10) into
nor-chrysomelidial (
14) and
nor-plagiodial (
13). The overall transformation requires; i) oxidation of the substrate at C(1) and C(8), ii) cyclization of the resulting dialdehyde to
nor-plagiodial followed by iii) isomerization to give
nor-chrysomelidial. The oxidase requires molecular oxygen as a cofactor and operates with removal of the pro-
R hydrogen from C(1) and C(8) of synthetic (1
R,8
R,2
E,6
E)–1,8–
2H
2–2,6–dimethyl–octa–2,6–diene–1,8–diol (
15), producing a dialdehyde along with H
2O
2. Unlike enzymes from iridoid-producing leaf beetle larvae, the
Philonthus enzyme is able to oxidize saturated substrates such as citronellol. Crude protein extracts prepared from
Philonthus glands by ammonium sulfate precipitation, were found to produce hydrogen peroxide at a rate of 0.085±0.003 ng H
2O
2 (ng protein)
−1 hr
−1 with nerol as an oxidase substrate. The cyclase operates with opposite stereochemistry to the enzyme(s) from
Phaedon cochleariae and other herbivorous leaf beetles, specifically removing the C(5)–H
R
hydrogen atom from (4
R,5
S,2
E,6
E)–4,5–
2H
2–2–methyl–octa–2,6–diene–1,8–diol (
17). These findings have enabled us to construct a detailed account of iridoid biosynthesis in rove beetles, which resembles the biosynthetic route in leaf beetle larvae, but exhibits distinct stereochemical differences.
Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in ~40° ...to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane and carbon dioxide, biomarkers, cultivation data, and gas compositions. Concentrations of indigenous microbial cells below 1.5 km ranged from <10 to ~10(4) cells cm(-3). Peak concentrations occurred in lignite layers, where communities differed markedly from shallower subseafloor communities and instead resembled organotrophic communities in forest soils. This suggests that terrigenous sediments retain indigenous community members tens of millions of years after burial in the seabed.
Non-unions are a relevant medical and socio-economic problem. Hyper-, oligo- and atrophic non-unions as well as septic and aseptic non-unions are differentiated. Correct classification is essential ...for the selected therapy. The "diamond concept" describes five pillars, on which bone healing is based and that have to be considered in the treatment of non-unions: osteogenic cells (mesenchymal stem cells), osteoinduction (growth factors), osteoconduction (scaffolds), mechanical stability, and vascularization. Factors that predispose to non-union also influence fracture healing. The gold standard of therapy are still resection of the non-union, decortication and autologous bone grafting. No advantage could be proven for any of the numerous procedures in monotherapy. But the combination of various procedures - polytherapy - seems to be promising. The aim is to optimize these concepts.
Bending tools are frequently used to manufacture freeform surfaces. In such cases, the geometry of the workpiece is determined wholly or in part by that of the tool (e.g. die forming). The quality of ...the finished product depends largely, therefore, on the geometry of the tools. Tool geometry is changed in the course of the manufacturing process by wear and optimisation. When the time comes for repairs or the manufacture of new tools, there is no record of the geometrical modifications which have been carried out. A model in the form of a quality control loop to feed back geometrical modifications to CAD and CAM systems is presented in this contribution. A means of creating the individual components in the quality control loop is described. Particular care has been taken to ensure that both the measurement and the feedback are limited to selected areas in order to minimise the cost and time involved.
Zusammenfassung
Posttraumatische Achsabweichungen stellen anspruchsvolle Indikationen zu Korrektureingriffen dar. Indikationsstellung und Planung bedürfen einer genauen, grafisch gestützten Analyse ...der Lokalisation und des Ausmaßes der Abweichung. Die Planungsdaten ergeben sich aus der Auswertung standardisierter, möglichst digitaler Röntgenbilder oder einer CT-Vermessung. Als Referenzen werden die Achsenverhältnisse der kontralateralen Seite und aus der Literatur bekannte Normalwerte benutzt. In der Regel wird die Osteotomie in der ehemaligen Frakturzone durchgeführt. Zur Fixierung verwendet man im metaphysären Bereich Platten, an den Diaphysen situationsabhängig Platten oder intramedulläre Implantate. Zur schrittweisen Korrektur komplexer Abweichungen stehen Fixateursysteme zur Verfügung. Der verbreitete Begriff der Fehlstellung sollte nicht mehr benutzt werden, da nicht jede Achsabweichung korrekturbedürftig ist und nicht immer auf einer fehlerhaften Vorbehandlung beruht.
Zusammenfassung
Posttraumatische Achsabweichungen und Pseudarthrosen im Bereich des Femurs sind bekannte Komplikationen nach Femurfrakturen. Neben Varus-, Valgus-, Ante- und Rekurvationsabweichungen ...treten insbesondere Malrotationen sowie Längenabweichungen auf. Nach Trümmerfrakturen im Schaftbereich liegen gehäuft Kombinationen der Achsabweichungen vor. Im Rahmen der Korrekturosteotomie stehen interne und externe Osteosyntheseverfahren zur Verfügung. Die Osteotomie mittels oszillierender Säge und Osteosynthese mittels Winkelplatte gilt dabei immer noch als „klassische Technik“ am proximalen und distalen Femur, im Schaftbereich wird häufiger die intramedulläre Nagelung durchgeführt. Unabhängig von der Methode und der Implantatwahl sind die oft mehrdimensionalen Korrekturen anspruchsvolle Operationen. Im Gegensatz zu vielen internen Methoden bieten die externen Osteosyntheseverfahren die Möglichkeit der Verlängerung einer Extremität sowie weiterer postoperativer Korrekturen. Dabei ist jedoch zu beachten, dass es zu verlängerten Behandlungszeiten sowie Komplikationen – wie Pintrackinfektionen – kommen kann.
Background. Color Doppler echocardiography is a standard technique for assessing mitral regurgitation before and after mitral valvuloplasty. Mitral valve prolapse produces complex eccentric jet flows ...that cannot be visualized and measured by two-dimensional color Doppler echocardiography. The aim of this study was to evaluate the clinical impact of three-dimensional color Doppler echocardiography, a new technique developed at our institution, for assessing mitral regurgitation.
Methods. Forty-five patients with mitral regurgitation underwent intraoperative transesophageal echocardiography and three-dimensional Doppler data acquisition. The grade of mitral regurgitation was assessed by angiography. The jet areas were calculated by planimetry from conventional color Doppler; the jet volumes were obtained by three-dimensional Doppler data.
Results. New patterns of mitral regurgitant flows were recognized according to the origin, direction, and spatial spreading into the left atrium. Conventional jet areas failed to separate the groups of patients with different degrees of regurgitation, whereas the jet volumes were able to divide patients with different regurgitation grades. No significant correlation was found between jet area and angiographic grading (r = 0.63,
p = NS). Jet volumes were significantly correlated to angiography (r = 0.89,
p < 0.001).
Conclusions. Three-dimensional color Doppler echocardiography revealed new patterns of regurgitant flow and allowed a more accurate semiquantitative assessment of complex asymmetrical regurgitant jets.
Pseudarthrosen Steinhausen, E.; Glombitza, M.; Böhm, H.-J. ...
Der Unfallchirurg,
07/2013, Letnik:
116, Številka:
7
Journal Article
Zusammenfassung
Pseudarthrosen stellen ein relevantes medizinisches und sozioökonomisches Problem dar. Unterschieden werden hyper-, oligo- und atrophe sowie septische und aseptische Pseudarthrosen. ...Die korrekte Klassifikation ist für die Therapie essenziell. Das „diamond concept“ beschreibt 5 Säulen, auf denen die Knochenheilung beruht und die bei der Pseudarthrosentherapie gleichwertig beachtet werden müssen: Osteogenese (Stammzellen) – Osteoinduktion (Wachstumsfaktoren) – Osteokonduktion (Gerüst) – mechanische Stabilität – Vaskularität. Einfluss haben zudem prädisponierende Faktoren des Patienten. Der Goldstandard in der Therapie sind Pseudarthrosenresektion, Dekortikation und autologe Spongiosaplastik. Für kein anderes der zahlreich zur Verfügung stehenden Verfahren wurde bisher in der Monotherapie eine Überlegenheit nachgewiesen. Die Kombination verschiedener Verfahren – die Polytherapie – erscheint jedoch Erfolg versprechend. Ziel ist es, die Konzepte zu optimieren.
Cosmic Probes of Fundamental Physics take two primary forms: Very high energy particles (cosmic rays, neutrinos, and gamma rays) and gravitational waves. Already today, these probes give access to ...fundamental physics not available by any other means, helping elucidate the underlying theory that completes the Standard Model. The last decade has witnessed a revolution of exciting discoveries such as the detection of high-energy neutrinos and gravitational waves. The scope for major developments in the next decades is dramatic, as we detail in this report.
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