The Molecular Weight Characterisation of Pinus radiata Bark Condensed Tannins

Crude condensed tannins extracted from Pinus radiata bark (sourced from Tokoroa) with various solvents (Hot water (HW), methanol/water/acetic acid (MWA), acetone/water (AW) and hot aqueous 2% sulphite/urea solution (SFU)) were subjected to Sephadex LH-20 column chromatography to purify the condensed tannins by removing carbohydrate and flavonoid components (crude extracts were approximately 70% condensed tannins). The condensed tannins from the HW and MWA extractions were then fractionated on a Sephadex LH-20 column using a stepwise gradient of methanol, water and acetone to separate the condensed tannins according to molecular weight (MW). Fractions were collected and pooled to give eight final fractions (HW 1-8 and MWA 1-8). Purified and fractionated condensed tannin fractions were then analysed with a range of techniques including 1H nuclear magnetic resonance (NMR) spectroscopy, acid/phloroglucinol depolymerisation coupled with high performance liquid chromatography (HPLC) with UV and MS detection, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionisation mass spectrometry (ESI-MS) and gel permeation chromatography (GPC). In the MALDI-TOF MS spectrum of the crude extracts the most intense signal was typically the tetramer peak and the decamer was typically the largest oligomer detected. In the spectra of late-eluting column fractions (i.e. HW and MWA 5-7) oligomers greater than the nonamer (DP up to 14) were detected and the most intense signal was shifted from the tetramer to higher MW oligomers. ESI MS showed itself to be better at analysing small MW condensed tannins. The MS results demonstrated that prior separation of the condensed tannins was effective in improving MS detection of higher MW oligomers. The mDP of the crude and fractionated fractions was obtained by depolymerisation/HPLC. The mean degree of polymerisation (mDP) of the purified condensed tannins ranged between 7.3 (AW) and 9.2 (SFU). The mDP of the fractionated condensed tannins ranged between 2 and 18. The depolymerisation/HPLC results of the fractionated condensed tannins were used to construct a GPC calibration curve of condensed tannin MW versus GPC retention time. To identify the GPC dimer peak a procyanidin dimer was synthesised by reacting condensed tannins with catechin under acidic conditions. Through the use of various NMR techniques (DEPT135, COSY, HSQC and HMBC experiments) the synthetic dimer was characterised and the 1H and 13C NMR spectra fully assigned. The GPC calibration curve enabled MW profiles for the HW and MWA 2-8 fractions and crude extracts to be obtained. GPC analysis confirmed the presence of larger oligomers that were not detected by MALDI-TOF MS and ESI MS. GPC number average MW results were in agreement with the average MW results obtained from depolymerisation/HPLC results. Pinus radiata bark condensed tannins from two different geographical locations (Golden Downs (Nelson) and Waimate (South Canterbury)) and different tree heights (0, 10 and 20 m) were analysed using the techniques described above to discover if there was any variability between samples. Trends that were observed between the different condensed tannins were decreases in condensed tannin yield and mDP as bark was obtained from higher up a tree. Extracts from New Zealand native bark (totara, rimu and kauri) were also analysed, showing that Rimu was the only bark of these species that contained significant amounts of condensed tannins. Overall this research has provided additional information on the structure and MW of P. radiata condensed tannins

Organization of a common information space in the teaching of mathematics, using the synergetic approach

The issues of organization of the process of teaching mathematicsin higher educational institutions, with the use of synergetic approach, based on the implementation of a common information educational space, are considered in the article.When implementing the process of teaching mathematics with the use of synergetic approach, it is implied that university students carry out complex scientific-research projects, within the framework of small groups, in terms of a dialogue of mathematical, information and various natural-science and humanitarian cultures. The essence of each of the projects is a multifaceted study of complex mathematical objects and processes by students of small groups, from the point of view of integrationof the arbitrarily obtained components of the finite set of initially existing chaotic complex of knowledge and skills of students. It is done with the purpose of development the complex mathematical models of objects, with the possibility of creation of various systems with their unique properties, characteristics and principles. The use of synergetic approach in the integration of complexscientific-research projects and distance learning allows to form the fundamentally new common information and education environment, which integrates knowledge from various scientific fields and academic disciplines. The implementation of such innovative method of teaching mathematics is of multi-stage nature. Individual representatives of each of the small groups carry out the corresponding profile activity, aimed at achieving the overall goal of the small group, within the framework of each stage. To organize the process of teaching mathematics in terms of considering the dialogue of cultures, using the synergetic approach, it is proposed to use the information environment, developed by V. V. Bogun, in the framework of a common information and education space. Keywords: common information and education environment, synergetic approach, teaching mathematics, dialogue of cultures, natural science disciplines, remote system of dynamic calculation projects

A Balance of Interests: the Concordance of Copyright Law and Moral Rights in the Worldwide Economy

LECTURE IN INTERNAL MEDICINE PROPAEDEUTIC

Isolated Potentials and Pace-Mapping as Guides for Ablation of Ventricular Tachycardia in Various Types of Nonischemic Cardiomyopathy

Nonischemic Cardiomyopathy and Ventricular Tachycardia.    Background : In patients with prior infarction, isolated potentials (IPs) during sinus rhythm reflect fixed scar and often indicate sites critical for ventricular tachycardia (VT). The purpose of this study was to determine the value of IPs in conjunction with pace-mapping to guide VT ablation in patients with various types of nonischemic cardiomyopathy. Methods : Mapping and ablation of VT were performed in 35 consecutive patients (26 men, age 55 ± 13 years, ejection fraction 0.31 ± 0.14) with VT and various etiologies of nonischemic cardiomyopathy. Pace-mapping was performed at sites with low voltage. Radiofrequency energy was delivered at sites with concealed entrainment or matching pace-maps. Results : One hundred ninety-five VTs (mean cycle length 363 ± 88 ms) were induced. Sites with prespecified ablation criteria displaying IPs during sinus rhythm were recorded in 21 of 35 patients (60%, IP-positive). In these patients, a total of 216 sites meeting prespecified ablation criteria were identified and 146 of 216 sites (68%) displayed IPs. Fifteen of 21 IP-positive patients (71%) no longer had inducible VT after ablation. In 14 of 35 patients, no sites with IPs where prespecified ablation criteria were met were identified (IP-negative) despite combined endocardial and epicardial mapping in 7 of 14 patients. Only 1 of 14 IP-negative patients (7%) no longer had inducible VT at the end of the ablation procedure. During a mean follow-up of 18 ± 13 months, 14 of 21 IP-positive patients (67%) remained arrhythmia-free, compared to 1 of 14 IP-negative patients (7%; P < 0.01). Half of the IP-negative patients had major adverse events due to recurrent arrhythmias, compared to none in IP-positive patients. Conclusion : IPs in conjunction with pace-mapping are helpful for identifying critical isthmus areas for ablation of VT in patients with various types of nonischemic cardiomyopathy. Patients with nonischemic cardiomyopathy in whom the arrhythmogenic substrate is characterized by IPs have a more favorable outcome than patients in whom IPs are absent. J Cardiovasc Electrophysiol, Vol. 21, pp. 1017-1023, September 2010)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79253/1/j.1540-8167.2010.01756.x.pd

Effect of Epicardial Fat on Electroanatomical Mapping and Epicardial Catheter Ablation

ObjectivesThe purpose of this study was to correlate 3-dimensional distribution of epicardial fat on computed tomography (CT) with electroanatomical (EA) voltage maps obtained during percutaneous epicardial mapping in order to determine the fat thickness cut-off that results in voltage attenuation and to establish normal ventricular epicardial voltage criteria in the absence of fat.BackgroundEpicardial fat can mimic scar tissue when epicardial voltage mapping is performed, as both result in low epicardial voltage. Cardiac CT can differentiate epicardial fat from scar or muscle on the basis of their distinct attenuations.MethodsTranscutaneous epicardial mapping was performed in a consecutive series of 14 patients. A cardiac CT was performed before the procedure and a 3-dimensional image of the epicardial fat was generated and registered with the epicardial EA voltage map.ResultsIn patients without cardiomyopathy (n = 8), a voltage ≥1.5 mV best correlated with the absence of epicardial fat. A fat thickness ≥2.8 mm resulted in voltage attenuation and best separated low voltage (<1.5 mV) from normal voltage (≥1.5 mV; sensitivity 81%, specificity 81%, area under the curve 0.85). In patients without cardiomyopathy, the low-voltage area matched well with the area of epicardial fat. In the 6 patients with nonischemic cardiomyopathy, the low-voltage area by far exceeded the area accounted for by epicardial fat; this corresponded with the presence of scar tissue. Epicardial ablations at sites with >10 mm of fat were ineffective.ConclusionsCardiac CT identifies epicardial fat that can mimic scar tissue during epicardial EA voltage mapping, which is important during epicardial mapping and ablation

Umwelt-, Risiko- und Nachhaltigkeitsdiskurs: Variationen des gleichen Themas?

Der Autor untersucht im Rahmen einer vergleichenden Literaturstudie einschlägige Publikationen über den Verlauf und die thematischen Stränge des Umwelt-, Risiko- und Nachhaltigkeitsdiskurses daraufhin, ob, inwieweit und anhand welcher Merkmale sie in sinnvoller Weise voneinander abgegrenzt werden können und in welchem Verhältnis sie zueinander stehen. Im Mittelpunkt stehen folgende Fragen: Welche Gemeinsamkeiten und Unterschiede ergeben sich, wenn Umweltprobleme im Kontext des Umwelt-, des Risiko- oder des Nachhaltigkeitsdiskurses behandelt werden? Gibt es überhaupt relevante Differenzen, oder handelt es sich eher um nur gering voneinander abweichende Spielarten des gleichen Themas, so dass die Begriffe synonym verwendet werden können? Sind Risiko- und Nachhaltigkeitsdiskurs als an bestimmte historische Verläufe gebundene Diskursvarianten bzw. -stränge des ökologischen Diskurses zu betrachten? Oder hat sich dieser umgekehrt unter dem aktuellen "master frame" der Nachhaltigkeit mehr oder weniger verflüssigt und aufgelöst? Der Autor grenzt sich bei seinen Ausführungen von einem weiten Begriffsverständnis ab, welches sämtliche Diskursbeiträge und -varianten, die sich mit der Umweltproblematik befassen, als Elemente des Umweltdiskurses begreift. Eine solche Begriffsverwendung verstellt seiner Meinung nach den Blick auf die zwischen den Diskursen bestehenden Differenzen. (ICI2

Umwelt- und Risikobewusstsein als Voraussetzung für Verhaltensänderungen in Richtung Nachhaltigkeit

"Der vorliegende Beitrag versucht zum einen zu zeigen, dass und warum es sinnvoll ist, Umwelt- und Nachhaltigkeitsprobleme als Probleme des gesellschaftlichen Umgangs mit Risiken sowie folglich auch die darauf bezogenen subjektiven Deutungs- und Einstellungsmuster als Risikobewusstsein zu begreifen. Zum anderen sollen empirische Befunde aus der Umweltbewusstseins- und der sozialwissenschaftlichen Risikoforschung dargestellt und unter der Fragestellung reflektiert werden, inwieweit sich hieraus potentielle Anknüpfungspunkte für Veränderungen der derzeitigen 'Produktions- und Konsummuster' im Sinne einer 'nachhaltigen Entwicklung' ergeben können. Hierzu werden zunächst wesentliche Bezüge zwischen den Konzepten Nachhaltigkeit und Risiko aufgezeigt (2). Anschließend wird am Beispiel der vielfach im Zentrum des Nachhaltigkeitsdiskurses stehenden globalen Umweltrisiken und eines darauf bezogenen Klassifizierungsansatzes des WBGU dargestellt, anhand welcher Kriterien in wissenschaftlichen Ansätzen versucht wird, diesen hochkomplexen Gegenstandsbereich zu strukturieren und unterschiedliche Risikotypen 'objektiv' zu unterscheiden und zu beschreiben (3). Dass sich demgegenüber die subjektive Risikowahrnehmung von Laien insbesondere vom engen technisch-naturwissenschaftlichen Risikokonzept deutlich unterscheidet, ist ein zentraler Befund der sozialpsychologischen Forschung zur Risikowahrnehmung. Im 4. Abschnitt wird ein Überblick über die hierfür als am wichtigsten geltenden qualitativen Risikomerkmale gegeben. Der 5. Abschnitt befasst sich anschließend mit konkreten empirischen Befunden zum Umweltbewusstsein sowie zur Risikowahrnehmung bzw. dem Risikobewusstsein der deutschen Bevölkerung. Diese werden im letzten Abschnitt unter der Frage diskutiert, inwieweit hieraus Chancen und Anknüpfungspunkte für einen Wandel des Konsumentenverhaltens abgeleitet werden können." (Textauszug

Wide QRS Tachycardia with Atrioventricular Dissociation and an HV Interval of 60 msec

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73193/1/j.1540-8167.1997.tb00814.x.pd