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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 207 (1998), S. 26-30 
    ISSN: 1431-4630
    Keywords: Key words Food ; Free amino acids ; Microwave-assisted extraction ; Shaking extraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  A microwave-assisted solvent extraction technique was developed for the extraction of free amino acids from foods. Four different samples were subjected to microwave extraction with varying amounts of extractant at several temperature values, for varying times to determine optimum extraction conditions. The extractions were performed with or without shaking the vessels in order to investigate the effects of mixing on the extraction efficiency and reproducibility. A comparison was made between this method and the traditional 1 h shaking extraction. The experiments indicated that the microwave-assisted extraction is an effective technique for the extraction of free amino acids from samples of plant or animal origin. The extraction yields obtained by the microwave method were about 10% better than by the conventional shaking technique. The times needed for the complete sample preparations were reduced by 66% with the application of microwaves.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 352 (1995), S. 520-528 
    ISSN: 1432-1912
    Keywords: Cardiac muscle ; Antiarrhythmic drugs ; Electrophysiology ; Recovery of V maX ; Action potential duration ; Rate-dependent block ; Sodium channels ; Potassium channels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cellular electrophysiological effects of dridocainide (EGIS-3966), a novel class I antiarrhythmic agent, was studied using conventional microelectrode techniques in canine cardiac Purkinje fibres and papillary muscle preparations obtained from humans and guinea-pigs. In each preparation, dridocainide (0.6–2 μmol/l) decreased the maximum velocity of action potential upstroke (Vmax) in a frequency-dependent manner, although marked differences were observed in its effects in Purkinje fibre and ventricular muscle preparations. In canine Purkinje fibres, action potential duration measured at 50% and 90% of repolarization was decreased, while action potential duration measured at 10% of repolarization was increased by dridocainide. In addition, the plateau of the action potential was depressed by the drug. These changes in action potential configuration were not observed in guinea pig or human papillary muscles. The offset kinetics of the dridocainide-induced V max block were different in Purkinje fibres and in ventricular muscle: the slow time constant of recovery of V max was estimated to be 2.5 s in dog Purkinje fibre and 5–6 s in human and guinea-pig papillary muscle. In guinea-pig papillary muscle, the rate of onset of the V max block was 0.15 and 0.2 per action potential in the presence of 0.6 and 2 μmol/l dridocainide, respectively. Dridocainide also decreased the force of contraction in this preparation. On the basis of the present results, dridocainide appears to posess mixed class LC and LA properties, with LC predominance in human and guinea-pig ventricular muscle. Present results also indicate that results of conventional classification of class I drugs may depend on the parameters chosen, as well as on the preparation selected.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Mund-, Kiefer- und Gesichtschirurgie 3 (1999), S. 146-151 
    ISSN: 1434-3940
    Keywords: Schlüsselwörter Jochbeinfraktur ; Wenig invasiver Therapiemodus ; Key words Zygomatic bone fracture ; Minimally invasive therapy modes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: The pre- and postoperative symptoms of zygomatic bone fractures were examined in a follow-up study to prepare a classification proposal. A differential indication for minimally invasive therapy modes was looked for with respect to this proposal. Therapy of isolated zygomatic bone fractures consisted in repositioning with a hook and miniplate fixation across the frontozygomatic suture. The aims of this study were clinical and radiological assessment of the repositioning result in terms of aesthetics and stability and quantification of the postoperative remission of disturbances of sensitivity of the infraorbital nerve. A total of 52 patients were examined. After the operation (on average after 3.5 days following the trauma) they were followed-up postoperatively for 12 months according to a strict schedule. Preoperatively, 49 patients reported disturbances of sensitivity of the infraorbital nerve. Other symptoms, such as periorbital haematoma and flattening of the zygomatic prominence, were observed in 49 patients and 45 patients, respectively. All fractures were repositioned well as assessed clinically and radiologically. The aesthetic result was evaluated as symmetric and durable in all cases. Six months postoperatively 41 patients reported normal sensitivity in the area of the infraorbital nerve. In only five patients (10.2%) was the sensitivity loss persistent throughout the entire follow-up period. Patients with primarily lacking diplopia developed neither eye motility disturbances nor postoperative enophthalmus in the following period. It can be concluded that the treatment of an isolated zygomatic bone fracture which satisfies aesthetic and functional requirements is possible by reposition and fixation with one miniplate at the lateral orbital rim. An additional osteosynthesis at the infraorbital rim or at the zygomaticomaxillary crista is not necessary. A routine revision of the orbital floor is only indicated in cases of preoperative diplopia. A zygomatic bone fracture connected with diplopia should be classified as combined zygomatic-/orbital floor fracture.
    Notes: In einer Follow-up-Studie wurden die prä- und postoperativen Symptome von Jochbeinfrakturen zur Erstellung eines Klassifikationsvorschlags bestimmt und eine Differentialindikation für einen möglichst wenig invasiven Therapiemodus aufgrund dieses Vorschlags gesucht. Der Therapiemodus bei isolierten Jochbeinfrakturen bestand aus einer Hakenreposition und der Fixation mit einer Miniplatte am zygomatikofrontalen Übergang. Ziele der Studie waren die klinische und radiologische Überprüfung des Erfolgs dieses Therapiemodus im Hinblick auf die Ästhetik, Stabilität und Gesichtskontur sowie die postoperative Remission der bei einer Jochbeinfraktur auftretenden Sensibilitätsstörungen des N. infraorbitalis bei diesem Therapiemodus. Erfaßt wurden 52 Patienten. Nach der Operation (im Mittel 3,5 Tage nach dem Trauma) wurden sie nach einem festen Schema bis zu 12 Monaten postoperativ nachkontrolliert. Präoperativ gaben 49 Patienten Sensibilitätsstörungen des N. infraorbitalis an. Andere Symptome wie Monokelhämatom und Abflachung der Jochbeinprominenz wurden in dieser Reihenfolge bei 49 Patienten bzw. bei 45 Patienten beobachtet. Das Repositionsergebnis war in allen Fällen sowohl klinisch als auch radiologisch zufriedenstellend und blieb auch dauerhaft bis zur letzten Nachuntersuchung nach 12 Monaten erhalten. Nach 6 Monaten hatten 41 Patienten keine Sensibilitätsstörung mehr. Lediglich 5 Patienten (10,2%) behielten eine über den Nachbeobachtungszeitraum andauernde Sensibilitätsstörung. Patienten mit primär fehlender Diplopie entwickelten auch in der Folgezeit keine Augenmotilitätsstörung noch kam es zu einem postoperativen Enophthalmus. Es kann geschlußfolgert werden, daß zu einer ästhetisch und funktionell suffizienten Versorgung einer isolierten Jochbeinfraktur die Reposition und deren Fixation mit einer Miniplatte über einen lateroorbitalen Zugang ausreichen. Eine zusätzliche Osteosynthese infraorbital oder im Bereich der Crista zygomaticoalveolaris ist nicht erforderlich. Eine routinemäßige Orbitabodenrevision ist nur bei einer präoperativ bestehenden Diplopie zwingend indiziert. Eine mit Diplopie vergesellschaftete Jochbeinfraktur sollte daher als kombinierte Jochbein-/Orbitabodenfraktur bezeichnet werden.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Mund-, Kiefer- und Gesichtschirurgie 2 (1998), S. 20-25 
    ISSN: 1434-3940
    Keywords: Schlüsselwörter Dentale Implantate ; Langzeituntersuchung ; Periimplantäre Weichgewebe ; Rehabilitation ; Kopf-Hals-Tumoren ; Key words Dental implants ; Follow-up examination ; Peri-implant soft tissue ; Rehabilitation ; Head and neck neoplasms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: The implantologic rehabilitation of patients after ablative oral tumour surgery and defect reconstruction is carried out generally without strict assessment of the successfulness of the outcome. Therefore 210 dental implants inserted in 58 tumour patients were subjected to regular follow-up examinations for 5 years. The Bone-Lock osseointegrated implant system (Howmedica Leibinger, Freiburg) was used exclusively. The plaque index (Silness and Löe), the sulcus bleeding index (Löe), the pocket probing depth, the width of the passive peri-implant tissue, implant mobility by means of the Periotest method and bone resorption according to X-ray findings were ascertained. At 60–70% of measurement points a passive peri-implant tissue was created. After the beginning of loading, specific adaptation phenomena of tumour patients could be detected. Despite constant plaque accumulation (mean 1.79), the bleeding disposition diminished from maximal 1.83 to 0.71. Corresponding to this finding the pocket probing depths decreased from 5.75 mm to 4.57 mm. The implant mobility (Periotest method: mean 2.25, range –3 to +8.5) showed a decrease in the first 2 years, then the values increased. The mobility depends on the kind of supraconstruction. Ball attachments have the lowest and implant-supported bridges have the highest values. Peri-implant bone resorption showed 1.43 mm as a mean value of all measurements and had a horizontal component of 73–84%. In accordance with this the vertical bone loss was small. After an increase during the first 2 years both values reached a steady state around 2.5 mm. The success rate for all 210 inserted implants is 83.2%. For implants in place for over 365 days the success rate is 93%. Prosthetic restoration in tumour patients can be achieved with osseointegrated dental implants according to the acknowledged international standards.
    Notes: Die implantologische Versorgung von Patienten nach ablativer Tumorchirurgie und Defektrekonstruktion erfolgt meist abseits strenger Maßstäbe der Erfolgsbeurteilung. Deshalb untersuchten wir die von Juni 1990 bis Juni 1996 bei 58 Tumorpatienten enoral gesetzten 210 Implantate regelmäßig nach. Verwendung fand ausschließlich das enossale Bone-Lock-Implantatsystem (Howmedica Leibinger GmbH, Freiburg). Untersucht wurden der Plaqueindex (Silness und Löe), der Sulkusblutungsindex (Löe), die Sondierungstiefe, die Breite der passiven Weichgewebe, die Implantatbeweglichkeit (Periotest) und der Knochenabbau im Röntgenbild. Die Schaffung passiver periimplantärer Weichteile gelang in 60– 70% der Meßorte. Es fanden sich nach dem Belastungsbeginn für Tumorpatienten spezifische adaptive Phänomene. Trotz gleichbleibendem Plaquebefall (Mittel 1,79) kam es im Beobachtungszeitraum (5 Jahre) zu einer deutlichen Abnahme der Blutungsneigung periimplantär von maximal 1,83 auf 0,71. Dem entsprach, daß die Sondierungstiefen von etwa 5,75 mm auf 4,57 mm um gut 1 mm abnahmen. Die mittels Periotest bestimmte Implantatbeweglichkeit (Mittelwert Periotest 2,25) nahm in den ersten 2 Jahren ab und danach wieder zu (Bereich –3 bis +8,5). Sie ist von der Art der Suprakonstruktion abhängig (Druckknopfversorgungen haben den niedrigsten, implantatgetragene Brücken den höchsten Wert). Der Gesamtknochenabbau periimplantär von maximal 1,43 mm im Durchschnitt aller Messungen zeigte eine horizontale Komponente von 73–84% mit einem entsprechend geringen vertikalen Einbruch. Nach einem 2jährigen Anstieg kam es zu einem „steady state.“ Die Erfolgswahrscheinlichkeit für alle 210 gesetzten Implantate liegt bei 83,2%. Für Implantate mit einer Liegedauer von 〉 365 Tagen beträgt sie 93%. Tumorpatienten können mithin implantologisch in einer den anerkannten Standards entsprechenden Weise versorgt werden.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Mund-, Kiefer- und Gesichtschirurgie 3 (1999), S. S74 
    ISSN: 1434-3940
    Keywords: Schlüsselwörter Vertikale Alveolarkammdistraktion ; Distraktionsimplantate ; Kieferkammatrophie ; Key words Distraction implants ; Vertical distraction ; Alveolar process ; Alveolar ridge atrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The masticatory rehabilitation of patients is dependent on the quality and volume of residual jaw bone. Loss of volume caused by tumor-related mandibular ridge resection or age-related atrophies may cause considerable problems. Reconstructive methods using free iliac bone, external tabula, or sandwich plasties are only a few examples of the common surgical treatment modalities. Doing without bone grafts, alveolar ridge augmentation by means of distraction osteogenesis might become a value method to improve the denture-bearing area. A new distraction implant system is shown and its first clinical use reported. Two distraction implants were inserted after an anterior segmental osteotomy. The alveolar ridge was then elevated 1 mm each day until the required augmentation of about 8 mm was achieved. After a latency period for pre-ossification of the callus, the distraction implants were replaced by the endosseous implants. The implant system and the surgical technique are shown, and the results are discussed. We believe that the implant distraction procedure will make useful contribution to the management of masticatory rehabilitation.
    Notes: Zusammenfassung Die kaufunktionelle Rehabilitation eines Patienten ist nicht zuletzt von der Qualität und dem Volumen des vorhandenen Kieferknochens abhängig. Volumenverluste nach tumorbedingten Unterkieferkastenresektionen oder altersabhängige Atrophien können hier erhebliche Probleme bereiten. Ersatzplastiken mit freiem Beckenkamm, Tabula externa oder Sandwich-Plastiken sind nur einige Beispiele für die bislang üblichen chirurgischen Behandlungsverfahren. Unter Verzicht auf Knochentransplantate könnte die Kieferkammaugmentation mit Hilfe der Distraktionsosteogenese hier einen wertvollen Beitrag zur Verbesserung des Prothesenlagers liefern. Es werden ein neues, implantatgestütztes System zur vertikalen Knochendistraktion vorgestellt und über einen ersten klinischen Einsatz anhand einer Einzelfallbeschreibung berichtet. Nach einer anterioren Segmentosteotomie wurden 2 Distraktionsimplantate inseriert, dann der Kieferkamm täglich um 1 mm bis zur gewünschten Augmentation um 8 mm angehoben. Nach einer 4wöchigen Latenzphase zur Frühossifikation des Kallus wurden dann die Distraktionsimplantate durch definitive enossale Implantate ersetzt. Insgesamt hat uns die klinische Anwendung ermutigt, den hier begonnenen Weg fortzusetzen. Implantatsystem und Operationstechnik werden erläutert, die Ergebnisse diskutiert.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Der Chirurg 68 (1997), S. 276-279 
    ISSN: 1433-0385
    Keywords: Key words: Lipomatosis colli ; Consevative neck dissection ; Schlüsselwörter: Lipomatosis colli ; funktionelle „neck dissection“
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Die Madelung-Launois-Bensaude-Lipomatose ist eine seltene Erkrankung, die durch ausgedehnte Fettansammlungen hauptsächlich in der Halsregion charakterisiert ist. Anhand einer Fallbeschreibung werden die klinischen Besonderheiten und der Verlauf dieser Erkrankung aufgezeigt. Eine bilaterale funktionelle „neck dissection“ konnte im speziellen Fall ein erneutes Rezidiv verhindern.
    Notes: Summary. Madelung-Launois-Bensaude lipomatosis is a rare disease characterized by an enormous accumulation of fat, mainly in the region of the neck. A case is presented to illustrate the course of the disease and its clinical features. In particular, the necessity for a bilateral conservative neck dissection is emphasized to avoid early recurrence.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Nonlinear dynamics 11 (1996), S. 121-141 
    ISSN: 1573-269X
    Keywords: d'Alembert principle ; reduced multibody method ; constrained flexibility ; nonlinear vibration ; Galerkin's method ; checking function ; differential and algebraic equations (DAE) ; bifurcation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The nonlinear response characteristics for a dynamic system with a geometric nonlinearity is examined using a multibody dynamics method. The planar system is an initially straight clamped-clamped beam subject to high frequency excitation in the vicinity of its third natural mode. The model includes a pre-applied static axial load, linear bending stiffness and a cubic in-plane stretching force. Constrained flexibility is applied to a multibody method that lumps the beam into N elements for three substructures subjected to the nonlinear partial differential equation of motion and N-1 linear modal constraints. This procedure is verified by d'Alembert's principle and leads to a discrete form of Galerkin's method. A finite difference scheme models the elastic forces. The beam is tuned by the axial force to obtain fourth order internal resonance that demonstrates bimodal and trimodal responses in agreement with low and moderate excitation test results. The continuous Galerkin method is shown to generate results conflicting with the test and multibody method. A new checking function based on Gauss' principle of least constraint is applied to the beam to minimize modal constraint error.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1572-8943
    Keywords: 3-amino-5-methylpyrazole ; FT-IR spectroscopy ; thermal decomposition ; transition metal complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Complexes represented by the general formula [MCl2L2] (M(II)=Zn, Mn, Co) and complexes of [Cu3Cl6L4] and CuSO4L2·4H2O, CoSO4L2·3H2O, [ZnSO4L3] where L stands for 3-amino-5-methylpyrazole were prepared. The complexes were characterized by elemental analysis, FT-IR spectroscopy, thermal (TG, DTG, DSC and EGA) methods and molar conductivity measurements. Except for the Zn-complexes, the magnetic susceptibilities were also determined. Thermal decomposition of the sulphato complexes of copper(II) and cobalt(II) and the chloro complexes of cobalt(II) and manganese(II) resulted in well-defined intermediates. On the basis of the IR spectra and elemental analysis data of the intermediates a decomposition scheme is proposed.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 34 (1996), S. 2467-2532 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A multiordering parameter model for glass-transition phenomena has been developed on the basis of nonequilibrium thermodynamics. In this treatment the state of the glass is determined by the values of N ordering parameters in addition to T and P; the departure from equilibrium is partitioned among the various ordering parameters, each of which is associated with a unique retardation time. These times are assumed to depend on T, P, and on the instantaneous state of the system characterized by its overall departure from equilibrium, giving rise to the well-known nonlinear effects observed in volume and enthalpy recovery. The contribution of each ordering parameter to the departure and the associated retardation times define the fundamental distribution function (the structural retardation spectrum) of the system or, equivalently, its fundamental material response function. These, together with a few experimentally measurable material constants, completely define the recovery behavior of the system when subjected to any thermal treatment. The behavior of the model is explored for various classes of thermal histories of increasing complexity, in order to simulate real experimental situations. The relevant calculations are based on a discrete retardation spectrum, extending over four time decades, and on reasonable values of the relevant material constants in order to imitate the behavior of polymer glasses. The model clearly separates the contribution of the retardation spectrum from the temperature-structure dependence of the retardation times which controls its shifts along the experimental time scale. This is achieved by using the natural time scale of the system which eliminates all the nonlinear effects, thus reducing the response function to the Boltzmann superposition equation, similar to that encountered in the linear viscoelasticity. As a consequence, the system obeys a rate (time) -temperature reduction rule which provides for generalization within each class of thermal treatment. Thus the model establishes a rational basis for comparing theory with experiment, and also various kinds of experiments between themselves. The analysis further predicts interesting features, some of which have often been overlooked. Among these are the impossibility of extraction of the spectrum (or response function) from experiments involving cooling from high temperatures at finite rate; and the appearance of two peaks in the expansion coefficient, or heat capacity, during the heating state of three-step thermal cycles starting at high temperatures. Finally, the theory also provides a rationale for interpreting the time dependence of mechanical or other structure-sensitive properties of glasses as well as for predicting their long-range behavior.
    Additional Material: 26 Ill.
    Type of Medium: Electronic Resource
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