Amitriptyline in the treatment of interstitial cystitis

Limited data and an accumulated body of anecdotal experience with the tricyclic class of antidepressants suggest that this group of drugs (especially amitriptyline) may be an effective treatment modality in nonulcerative interstitial cystitis. Both the ease of administration and the relatively rapid onset of relief make these types of drugs appropriate to consider for first-line therapy after bladder distention has failed.     

A monotone multigrid solver for two body contact problems in biomechanics

The purpose of the paper is to apply monotone multigrid methods to static and dynamic biomechanical contact problems. In space, a finite element method involving a mortar discretization of the contact conditions is used. In time, a new contact-stabilized Newmark scheme is presented. Numerical experiments for a two body Hertzian contact problem and a biomechanical application are reported. This work was supported by the DFG Research Center Matheon.     

Der submikroskopische Bau der Faserzellwand beim Zugholz der Pappel

Zusammenfassung In Erg?nzung früberer Untersuchungen wurden von methacrylat-eingebettetem Zugholz- und Normalfasergewebe vonPopulus euramericana cv.regenerata ultradünne Quer- und L?ngsschnitte hergestellt. Die elektronen-mikroskopische Untersuchung zeigt, da? die Zellwand der Zugholzfaser aus Mittellamelle, Prim?rwand, den Sekund?rwandschichten 1 bis 3 sowie einer Immenseitigen Abschlu?lamelle besteht. Die S₃ stellt dabei die für Zugholzfaser charakteristische gelatin?se (G-)Schicht dar. Die Struktur dieser G-Schicht kann elektronenmikroskopisch nur durch Herausl?sen des Einbettungsmediums deutlich sichtbar gemacht werden. In solcher Weise behandelte Ultradünnschnitte lassen erkennen, da? die G-Schicht eine Wabenstruktur besitzt, in der einzelne cellulosische Lamellen durch Haftpunkte miteinander verbunden sind. Wahrscheinlich sind die Kammern des Wabensystems mit quellbaren Interlamellarsubstanzen ausgefüllt, die in Verbindung mit der Wabenstruktur die bekannten L?ngszugspannungen im Zugholz verursachen k?nnten. Die Entstehung dieser Spannungen ist sowohl als Folge einer Quellung, wie auch als Folge einer Entquellung der G-Schicht denkbar. Die M?glichkeit von Strukturver?nderungen durch die angewendeten Pr?parations vefahren wird ausführlich er?rtert. Es wird nachgewiesen, da? die beschriebeue Wabenstruktur der G-schicht nicht den wabigen Strukturen entspricht, die sich durch S?urebehandlung in der zentralen Sekund?rwandschicht normaler Faserzellen erzeugen lassen.

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The submicroscopic structure of the fibre cellwall in poplar tensionwood

Summary In addition to preliminary investigations, ultrathin cross-and and longitudinal sections of tensionwood and normal wood tissue from Populus euramericana cv. regenerata were investigated. These tissues were embedded in methacrylate and examined with an electronmicroscope. It was found that the cell wall of tensionwood fibres of this species is composed of middle lamella, primary wall, and secondary wall. The latter consists of three layers (S₁, S₂, S₃) and is bordered on the lumen side by a terminating lamella. In tensionwood, the S₃ appears as a characteristic gelatinous (G) layer. The detailed structure of this G-layer can be clearly seen only when the embedding material is dissolved, its density being very similar to that of the cellulose lamellae of the G-layer. The methacrylate embedding material having been removed, is was found that the G-layer posseses a honeycomb-structure in which the individual cellulose lamellae are firmly connected at irregularly spaced intervals. It is supposed that the interlamellar spaces of this honeycomb-structured G-layer are filled with substances which are able to swell and shrink. It is postulated here that the inherent tensional strains and the resulting longitudinal contraction of tensionwood fibers and tissue, commonly observed, might be caused by either the swelling or shrinking of interlamellar substances within the G-layer. Swelling might cause longitudinal contraction, if these substances swell mostly in radial direction. This radial swelling results in a radial expansion and, consequently, longitudinal contraction of the individual cavities of the honeycomb structure. On the other hand, the commonly observed longitudinal confraction of tensionwood fibres and tissue might also be explained by shrinking. In this case, the interlamellar substances must be mostly isotropic, and thus their shrinking and consequently that of the tensionwood tissue would occur in all directions. The methods used to establish that the honeycomb structure of the G-layer is not an artifact of the preparation, are also described. It is proven that the G-layer structure as described in this paper is not the same as the honeycomb structure produced by the treating of fibre cells of normal wood tissue with acid.

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Beitrag zu den Verhandlungen der Arbeitsgruppe Wood Quality der IUFRO-Sektion 41 in Madison, USA, vom 11. bis 13. September 1963.     

Inhibitoren der Korrosion (8) Über die Abhängigkeit der Korrosionsinhibierung des Eisens in Salzsäure von der Struktur quartärer Phosphoniumsalze

Inhibition of the corrosion of iron in hydrochlorid acid as a function of the structure of quaternary phosphonium salts In the case of quaternary phospho-nium salts there is no direct relation between their inhibiting power in deaer-ated acid media and the polarographi-cally determined reduction potentials. The inhibiting effect can in a first line be attributed to sterical factors con-nected with the fragments formed after incorporation of two electrons and be-coming fixed to the iron surface. Biphosphonium salts having saturated or unsaturated bridges are excellent in-hibitors under the conditions mentioned. Most efficient are biphosphonium salts having chaines of 4 to 10 methylene groups between the phosphonium cen-tres. The rigid p-phenylene radikal is less suitable as a linking principle. Phe-nyl phosphine and diphenyl phosphine in low concentrations accelerate corro-sion and exhibit a protective effect only in higher concentrations. Polymers having incorporated phos-phonium centres are only moderate inhibitors when compared to biphospho-nium salts. The synthesis is outlined and some physical and chemical properties are given.     

Inhibitoren der Korrosion 10 (1). Nachweis der Sekundärinhibition durch Allyl-triphenyl-phosphonium- bzw. arsoniumbromid und N-Allyl-chinaldiniumbromid

Corrosion inhibitors (10) Demonstration of the secondary inhibition by allyl triphenyl phosphonium and arsonium bromides and N-ally1 quinaldinium bromide Triphenyl allyl phosphonium (1) and arsonium (2) salts as well as allyl quinaldinium bromide (4) are corrosion inhibitors of moderate efficiency. In acid media they are reduced by carfinyl iron powder to yield triphenyl phosphine and triphenyl arsine respectively and quinaldine. The two products mentioned the first form a layer on carbonyl iron and, after extraction, may be identified by gas chromatography. The allyl group is eliminated by iron from 1, 2 and 4, yielding Pro-pene, propane and, probably, cyclopropane. The hydrocarbon quantities determined by gas chromatography are in good agreement with the values found in the gravimetric determination of allyl-onium salts after the reaction. Ally triphenyl phosphonium bromide ( I ) and allyl diphenyl sulfonium tetraborate (3) yield propene and propane in a 1:1 ratio. In the case of (2) and (4) this ratio is shifted to 14:l and 7:l respectively. The hydrocarbon proportion in the gas mix-ture is higher at the beginning of the reaction than toward its end; at the beginning, the Propane:propene ratio is also displaced, the formation of propane having priority.