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Energiearme angeregte Singulettzustande von Alkylallencarbonsauren und ihrer Anionen sowie allgemein der Substituenteneffekt der Carboxylgruppe auf Grundzustandseigenschaften des Allensystems werden mit Hilfe von Circulardichroismusspektroskopie, Absorptionsspektroskopie und CNDO/S-Rechnungen untersucht. Die Circulardichroismusspektren zeigen, das den intensiven ersten ππ*-Ubergangen der Sauren bzw. ihrer Anionen drei schwache Ubergange vorgelagert sind, die in Form nur einer Absorptionsbande auftreten. Bezogen auf die Butadien-(2,3)-saure (“Allencarbonsaure”) und ihres Anions sind es S(A) angeregte Zustande, die durch ππ*-Ubergange und ππ*-bzw. ππ*-Anregungen entstehen. Die Untersuchungen der Grundzustandseigenschaften der Systeme beziehen sich vor allem auf die Elektronendichteverteilung sowie die mesomeren Wechselwirkungen der Carboxylgruppe mit dem Allengerust. Low-energy electronically excited singlet states of alkylallenecarboxylic acids and their anions as well as the substituent effect of the carboxylic group on ground state properties of the allenic system are studied by means of circulardichroism spectroscopy, absorption spectroscopy, and CNDO/S-calculations. The circulardichroism spectra reveal three weak transitions below the intense ππ* transitions of the acids and the first ππ* excitation of the anions, respectively. All these three transitions correspond to only one band of their absorption spectra. With reference to 2,3-butadienoic acid (“allenecarboxylic acid”) and its anion, they are of S(A) type and result from a ππ* transition and ππ* as well as ππ* excitations.

We have isolated and characterized a new yeast mutation in the glucosylation steps of lipid-linked oligosaccharide biosynthesis, alg8-1. Cells carrying the alg8-1 mutation accumulate Glc1Man9GlcNAc2-lipid both in vivo and in vitro. We present evidence showing that the alg8-1 mutation blocks addition of the second alpha 1,3-linked glucose. alg8-1 cells transfer Glc1Man9GlcNAc2 to protein instead of the wild type oligosaccharide, Glc3Man9GlcNAc2. Pulse-chase studies indicate that the Glc1Man9GlcNAc2 transferred is processed more slowly than the wild type oligosaccharide. The yeast mutation gls1-1 lacks glucosidase I activity (Esmon, B., Esmon, P.C., and Schekman, R. (1984) J. Biol. Chem. 259, 10322-10327), the enzyme responsible for removing the alpha 1,2-linked glucose residues from protein-linked oligosaccharides. We demonstrate that gls1-1 cells contain glucosidase II activity (which removes alpha 1,3-linked glucose residues) and have constructed the alg8-1 gls1-1 haploid double mutant. The Glc1Man9GlcNAc2 oligosaccharide was trimmed normally in these cells, demonstrating that the alg8-1 oligosaccharide contained an alpha 1,3-linked glucose residue. A novel Glc2 compound was probably produced by the action of the biosynthetic enzyme that normally adds the alpha 1,2-linked glucose to lipid-linked Glc2Man9GlcNAc2. This enzyme may be able to slowly add alpha 1,2-linked glucose residue to protein-bound Glc1Man9GlcNAc2. The relevance of these findings to similar observations in other systems where glucose residues are added to asparagine-linked oligosaccharides and the possible significance of the reduced rate of oligosaccharide trimming in the alg mutants are discussed.

The one-bond carbon-nitrogen coupling constant of diazomethane is reported. Analogies with carbon-carbon coupling constants in allenes are emphasized. CNDO/S-calculations are used as a support of the suggestions the C-N coupling in diazomethane to be dominated by the Fermi contact mechanism and the sign of the carbon-nitrogen-15 coupling constant to be negative

The electronic structure of monosubstituted allenes has been investigated by means of photoelectron and UV absorption spectroscopy.—The assignment of the photoelectron and UV absorption bands is achieved on the basis of a “composite molecule” (LCMO) model and substantiated by comparisons with structurally related molecules.—Assuming the validity of Koopmans' approximation for the interpretation of photoelectron spectra the π electronic structure of allenes can be rationalized quantitatively in terms of a three-parameter model of substituent effects which involves short-range and long-range inductive effects and resonance effects.—The substituent effect on the highest-occupied σ orbital of allenes is shown to be essentially an electrostatic (long-range) field effect. The interpretation of low-energy 1A” excited states of allenes is achieved via a correlation of UV spectroscopic and photoelectron spectroscopic data.—The interpretation of experimental results is corroborated and refined by semiempirical (CNDO/S) and ab initio (STO-3G and STO-4.31G) calculations.—In general, there are analogies of the molecular properties of allenes with those of ethylenes and benzenederivatives and with those of carbonylcompounds and acetylenes. Mit Hilfe der Photoelektronen- und UV-Absorptionsspektroskopie wird die Elektronenstruktur monosubstituierter Allene untersucht.—Eine Zuordnung der Photoelektronen- und UV-Absorptionsbanden erfolgt auf der Basis eines I.CMO-Modells sowie durch Vergleiche mit strukturell ahnlichen Molekulen.—Unter der Voraussetzung der Gultigkeit von Koopmans' Naherung fur die Interpretation der Photoelektronenspektren lassen sich die Substituenteneinflusse auf die π-Elektronenstruktur der Allene quantitativ durch ein Drei-Parameter-Modell beschreiben. Dabei werden induktive short-range und long-range-Effekte sowie Resonanzeffekte unterschieden. Der Substituenteneffekt auf das hochste besetzte σ-Orbital der Allene ist weitgehend ein elektrostatischer (long-range)-Feldeffekt. Die energiearmen Anregungszustande der Symmetrie 1A” bei den Allenen konnen uber eine Korrelation von UV-Absorptions- und Photoelektronenbandenverschiebungen interpretiert werden.—Die experimentellen Befunde werden durch semiempirische (CNDO/S) und ab initio (STO-3G und STO-4.31G)-Rechnungen abgesichert und im Detail erweitert.—Ganz allgemein lassen die Molekuleigenschaften der Allene Analogien zu Athylenen und Benzolderivaten sowie zu Carbonylverbindungen und Acetylenen erkennen.

The termini of Saccharomyces cerevisiae chromosomes consist of tracts of C1-3A (one to three cytosine and one adenine residue) sequences of approximately 450 base pairs in length. To gain insights into trans-acting factors at telomeres, high-copy-number linear and circular plasmids containing tracts of C1-3A sequences were introduced into S. cerevisiae. We devised a novel system to distinguish by color colonies that maintained the vector at 1 to 5, 20 to 50, and 100 to 400 copies per cell and used it to change the amount of telomeric DNA sequences per cell. An increase in the number of C1-3A sequences caused an increase in the length of telomeric C1-3A repeats that was proportional to plasmid copy number. Our data suggest that telomere growth is inhibited by a limiting factor(s) that specifically recognizes C1-3A sequences and that this factor can be effectively competed for by long tracts of C1-3A sequences at telomeres or on circular plasmids. Telomeres without this factor are exposed to processes that serve to lengthen chromosome ends.

Naherungsansatze zur semiempirischen Berechnung 13C-chemischer Verschiebungen von Allenen werden experimentell nachgepruft. Die berechneten und beobachteten Verschiebungen komplexer Allene mit verschiedenartigsten Substituenten zeigen gute Ubereinstimmung. Korrelationen der Verschiebungsparameter mit ublichen Substituentenkonstanten vermitteln Einsichten in den Gultigkeitsbereich der Naherungsansatze und in physikalische Grosen, die die 13C-chemischen Verschiebungen bestimmen. Approximations for the semiempirical calculations of 13C-chemical shifts of allenes are experimentally tested. The calculated and observed shifts of complex allenes with various substituents show an overall good agreement. Correlations of the shift parameters with usual substituent constants reveal some insight into the range of validity of the approximations and into physical qualities determining the 13C-chemical shifts.

Summary The reactive power due to phase displacement caused by controlled line commutated convertors can be avoided by the use of forced commutation whereby the line current is cut off before the voltage reverses. The basic problems of forced-commutation devices are presented by examples of wellknown circuits. Using these circuits as a basis convertors are described and analysed, whose forced commutation is assisted by a supporting capacitor. It is paralleled to the AC side during the whole commutation period. This effects a soft “cut-off” of the line current with comparatively low over-voltage or markedly lower capacitor expenditure. The reactive power loading of the supporting capacitor permits the use of smoothing capacitors. The principle is equally suitable for application in convertors during inverter operation.

Ein im wesentlichen algebraisches Modell wird benutzt, um Eigenschaften von Funktionen zur numerischen Erfassung 13C-chemischer Verschiebungen von Allenen zu diskutieren. Durch konsequenten Bezug auf das physikalische Phanomen last sich zeigen, das Additivitatsbeziehungen, d. h. Summen ligandenspezifischer Parameter, die beobachtbaren Effekte innerhalb dieser Molekulklasse prinzipiell nicht beschreiben konnen. Naherungsansatze fur die semiempirische Berechnung 13C-chemischer Verschiebungen von Allenen werden vorgeschlagen. An essentially algebraic model is used to discuss the properties of functions for the description of 13C-chemical shifts of allenes. With reference to the physical phenomenon it is shown that in principle additivity relationships, i.e. sums of ligand specific parameters, cannot describe the observed effects within this particular class of molecules. Approximations for the semiempirical calculations of 13C-chemical shifts of allenes are given.

A comparison between calculated and observed values demonstrates that “ansätze” derived from an algebraic model in connection with appropriate boundary conditions are able to account for a quantitative description of the proton chemical shifts of allenes. Correlations of the proton chemical shifts with other NMR data, such as 13C-chemical shifts and one-bond carbon-proton coupling constants, reveal some insigths into the nature of the 1H substituent chemical shifts of alienes.

On the basis of calculated CNDO/S electron densities. STO-3G gross atomic populations, and dipole moments the electron density distributions in variously substituted allenes are investigated.—The structure of the π system in monosubstituted allenes and the influences of the substituents are discussed in terms of conjugation, hyperconjugation. and polarization effects.—For the predictions of total electron densities of CNDO/S quality for the carbon and the hydrogen atoms of the allenic skeleton a simple procedure is proposed. Auf der Grundlage von berechneten CNDO/S-Elektronendichten. STO-3G-Atompopulationen und Dipolmomenten werden die Elektronendichteverteilungen substituierter Allene untersucht.—Die Struktur des π-Systems monosubstituierter Allene und die Substituenteneinflusse werden uber Konjugations-, Hyperkonjugations- und Polarisationseffekte diskutiert.—Fur die Vorhersage von Gesamtelektronendichten der Kohlen- und Wasserstoffatome des Allengerustes, die qualitatsmasig denen der CNDO/S-Rechnungen entsprechen, wird ein einfaches Verfahren vorgeschlagen.

Nach einer einmaligen Gabe von Synthalin A (10 mg/kg subkutan) an 1–5 Tage alte Ratten tritt an den A-Zellen des Inselorgans keine zytologisch erkennbare Schadigung auf, wie sie bei ausgewachsenen Tieren beschrieben wurde. Schollen-, Blasen- und Trummerstadien konnten in keinem Falle erzeugt werden. Hingegen wurde an den A-Zellen behandelter Tiere eine einschneidende Verminderung der Mitosefrequenz und eine Schadigung der vorhandenen A-Zellmitosen festgestellt, die als selektiv bezeichnet werden mus, da die B-Zellmitosen und die Teilungsfiguren der exokrinen Zellen in quantitativer und qualitativer Hinsicht intakt sind.

Wenn die Spannung an der Anfachung in Kreis I gegeben ist durch eI=− α iI+β iI3 und die Spannung am Widerstand in Kreis II gegeben ist durch eII=+rii · iII, gelten folgende Satze: 1. Es sind nur die Amplituden\(J_{1_0 } 2 = \frac{{\alpha - \beta _1 }}{{\frac{3}{4}\beta }}\) oder\( J_{2_0 } 2 = \frac{{\alpha - R_2 }}{{\frac{3}{4}\beta }}\) (gemessen in Kreis I) stabil moglich. 2. Ein Ziehbereich ist nur moglich, wenn y2 fur ein ξ mehrere Werte annehmen kann (wenn k>d) und wenn α>R. Wenn α

A series of six 2,4,4-substituted allenecarboxylic esters R1R2CCC(R3)COOAlk has been found to exhibit O-Alkyl cleavage as the most prominent feature of both their 70 and 12 eV mass spectra. Loss of linearity of the allene system upon ionization, followed by conversion of the molecular ion to a 5-membered cyclic isomer, is thought to induce this unusual mode of bond rupture. Oxygen-migration from the ester function to C-4 as is indicated by the subsequent decomposition of the [M — Alk] ions to [R1CO]+ and [R2CO]+ fragments can be taken as direct evidence in favour of this rationale.

This paper presents the results of data transmission tests made on both single-link and multi-link tropospheric beyondthe-horizon radio systems. Tests were made at 750 or 1300 bits per second employing both double sideband AM and FM methods of data modulation. In the single-link tests the data performance was determined for various transmission parameters such as median channel noise, peak channel noise, radio received carrier level, and order of diversity. Data were satisfactorily transmitted on a 2400mile circuit consisting of nine different beyond-the-horizon paths and six line-of-sight paths. The FM-type data modulation was notably superior to the AM type.

In den Langerhansschen Inseln der Ente fallt die histochemische Reaktion auf Zink nach vitaler intravenoser Injektion von Dithizon stark positiv aus. Die uberwiegend aus B-Zellen bestehenden „hellen“ Inseln und die fast nur aus A-Zellen bestehenden „dunklen“ Inseln erlauben den Ausfall der Reaktion und die Lokalisation des Zinkdithizonates innerhalb der Inselzellen in beiden Inselzelltypen getrennt zu beurteilen. Zinkdithizonat in granularer Form findet sich sowohl in den A-Zellen als auch in den B-Zellen. Es ist in ersteren violettrot, in letzteren karminrot. In den A-Zellen deckt sich bei intravitaler Reaktion das Zinkvorkommen nicht mit den α-Granula. Am nativen Gefrierschnitt ist das Metalldithizonat beim Zinknachweis nicht granular, sondern diffus im ganzen Cytoplasma nachzuweisen. Das gleiche gilt fur die B-Zellen. Die beiden Methoden haben lokalisatorisch einen verschiedenen Effekt. In beiden Zelltypen der Inseln wird auser dem roten Zinkdithizonat eine schuttere schwarze Kornelung gefunden, die moglicherweise das Vorhandensein eines weiteren Schwermetalles anzeigt. Das Vogelpankreas eignet sich in besonderem Mase fur Untersuchungen, welche den Zinkgehalt der A-Zellen im Zusammenhang mit dem Kohlenhydratstoffwechsel betreffen.

Synthalin given subcutaneously to ducks causes no changes in the islands of the pancreas, but severely damages the kidneys.

Unte r me inem Material fanden sieh insgesamt folgende k l in i sche Typen: Fii l le der k m e n t i a g r u p p e . . . . . . . . . . . . 7 = 29 pCt. , yon de l i ran ten Psychosen . . . . . . . . . 3 = 12,5 , ,, ,, infekt iSsen Sehwaehezus t anden . . . 1 4 , 2 ,, ,, , , apa t h i s ehen Zus tanden . . . . . . . . 3 = 8,4 ,, ,, ,, Depress ionen . . . . . . . . . . . . . 6 = 2 5 ,, , ,, Psychosen psychogenen Geprages . . 2 = 8,4 ,, ,, ,, Ka ta ton ie . . . . . . . . . . . . . . . 2 = 8,4

An Hoden von menschlichen Feten (Scheitel-Fersenlange 20–42 cm) wurden die Fettfarbung mit Sudanschwarz B, der Cholesterinnachweis und die Reaktion auf Ketongruppen (NAHD) ausgefuhrt. Alle Reaktionen fielen in den Zwischenzellen am starksten, in den Sertolizellen schwacher aus. Alle ubrigen Gewebsbestandteile des Hodens verhielten sich negativ.

Es wird uber einen Fall von „Maladie des Tics convulsifs“ mit Koprolalie berichtet und die Wahrscheinlichkeit einer infektiosen Genese und organischen Grundlage desselben erwiesen sowie die Ahnlichkeit und Ubereinstimmung einer groseren Anzahl von Symptomen des Falles mit jenen bei anderweitigen Erkrankungen des subkortikalen motorischen Systems hervorgehoben. Die Genese der Koprolalie wird erortert. Wahrscheinlich ist es, das zum mindesten ein Teil der typischen, von Gilles de la Tourette zuerst beschriebenen Falle von Maladie des Tics convulsifs eine organische Grundlage haben, vielleicht auch zum Teil aus der Chorea minor hervorgehen.

Monoclonal antibodies specific for a rat tumor-associated protein cross-react with a similar protein present in the cytosol of the rat fetus. The oncofetal protein exists as two species of approximate molecular weight 50 and 55 kDa which promote the transport of RNA from isolated nuclei. During rat fetal development, the protein first increases in concentration from approximately 12 to 16 days gestation and then drops to non-detectable levels perinatally.

Pain from ureteral stones is believed to be due to spasm and hyperperistalsis of the involved ureter. Nifedipine has been shown to decrease human ureteral spasm in vitro . Conflicting results have been reported concerning the clinical efficacy of nifedipine in relieving acute renal colic. This prospective, double-blind, crossover clinical trial evaluated the acute pain relief obtained in 30 patients who had ureteral stones. All patients had ureteral stones documented either by plain abdominal radiograph (six), intravenous pyelogram (16), or passage of the stone(s) in the urine (eight). Each patient served as his own control. The mean pain relief scores for placebo versus 10 to 20 mg oral nifedipine were 0.7 ± 1.8 and 1.2 ± 2.5, respectively, as measured on a visual analogue scale ( P = .404). Seven patients received clinically significant relief associated with nifedipine, and three patients received relief from placebo ( P = .300). Twenty patients (66%) did not experience clinically significant relief from either treatment. We conclude that nifedipine does not differ significantly from placebo in providing relief from acute renal colic.

A single subcutaneous injection of synthalin-A does not affect the cytoplasma ofA-cells in pancreatic islets of the rat during the 1st–5th day of life, in contrast to adult animals. Selective action was found on mitoticA-cells: reduction of mitotic frequency to 25% of the normal rate, and pathological mitoses in the sense of the so-called primary effect. The mitoses ofB-cells, exocrine pancreatic cells and intestinal epithelia seemed to be unchanged, although the mitotic rate was higher than inA-cells.

Nach Kap.l soll das vollstandige mathematische Modell eines elektrohydraulischen Systems durch eine automatische Verknupfung von mathematischen Teilsystemen generiert werden. Um diese auch programmtechnisch realisieren zu konnen, mussen eindeutige Schnittstellen zwischen den mathematischen Teilsystemen (im weiteren Verlauf der Arbeit auch als Simulationsbausteine bezeichnet) definiert und immer wiederkehrende Regeln zu ihrer Verknupfung vereinbart werden. Fur diese Festlegung braucht der innere Aufbau der zu koppelnden Simulationsbausteine nicht bekannt zu sein.

Acute myocardial necrosis was produced in 27 anesthetized dogs by repetitive DC 75 joule shock delivered with one electrode in the left ventricular cavity and the other on the left chest wall. A total of 1 shock/kg body weight delivered at 10 sec intervals resulted in discrete anterior wall necrosis of 7% to 31% (mean, 17.6%) of the mass of left ventricular myocardium. After some transient bradycardia, normal sinus rhythm was restored. Depression of left ventricular function 15 min after shock (rise in LVEDP from 4.0 +/- 1.5 to 17 +/- 2 mm Hg and fall in cardiac output from 2.29 +/- 0.24 to 1.82 +/- 0.12 L/min) recovered only slightly during the ensuing 2 hr. A significant correlation (r=0.85) was observed between the LVEDP at 2 hr after shock and the extent of necrosis determined histochemically and histologically at the time of sacrifice 3 hr after shock. Thus, in this form of acute myocardial damage, pump dysfunction is closely related to the area of necrosis.

This article is intended as an overview of emergencies that could and often do present to the physician's office, especially when a hospital emergency department may not be nearby. It is not intended as an in-depth view of every problem but should be considered as a presentation of essential management in the emergency phase of treatment. The reader is directed to the references for more in-depth information on these topics.

Nach Kap.2.4 werden die Genauigkeit, die numerische Stabilitat und die Rechenzeit fur die Losung eines DGL-Systems stark von charakteristischen Grosen wie Wertebereiche der Zustandsregelung ZV und der Zeitkonstanten T beeinflust. Diese werden von den problemspezifischen Eigenschaften des zu untersuchenden physikalischen Systems bestimmt. Um ein optimales Verfahren zu erhalten, sind daher eingehende Untersuchungen notwendig. Die zusammengefaste Vorgehensweise zeigt Bild 5.1.

The organophosphate insecticide Diazinon has been reported to cause acute pancreatitis in dogs. Based on histochemical examination of the acinar tissue, it was suggested that pancreatic tissue-fixed butyrylcholinesterase (BuChE) is the target enzyme of organophosphate toxicity. To further evaluate this theory, we exposed dogs, cats, and guinea pigs to a single sublethal dose of the organophosphate insecticide Diazinon (75 mg/kg). In cats, which lack pancreatic BuChE, no pathological changes occurred after two, three, and six hours, whereas in the guinea pigs as in dogs, both having abundant pancreatic BuChE, vacuolization of the acinar cells, interstitial edema and vasculitis indicate acute edematous pancreatitis as early as two hours. Atropine pretreatment (0.2 mg/kg) gave complete protection against pancreatitis. It was concluded that inhibition of pancreatic BuChe leads to cholinergic hyperstimulation of the acinar cell, which results in acute pancreatitis, and that pancreatic BuChE is essential for dogs and guinea pigs to downregulate cholinergic excitation. The insecticide pancreatitis model is considered a simple, non-invasive, reproducible, and cheap and useful method to evaluate early changes and methods of treatment in acute pancreatitis. Pancreatitis in humans has also been reported after accidental insecticide exposure.

The reactive power due to phase displacement caused by controlled line commutated convertors can be avoided by the use of forced commutation whereby the line current is cut off before the voltage reverses. The basic problems of forced-commutation devices are presented by examples of well-known circuits. Using these circuits as a basis convertors are described and analysed, whose forced commutation is assisted by a supporting capacitor. It is paralleled to the AC side during the whole commutation period. This effects a soft “cut-off” of the line current with comparatively low over-voltage or markedly lower capacitor expenditure. The reactive power loading of the supporting capacitor permits the use of smoothing capacitors. The principle is equally suitable for application in convertors during inverter operation.

Detailed enzyme kinetic parameters of the reactions catalyzed by the two 17beta-hydroxysteroid dehydrogenases (17beta-HSD), which were solubilized from the microsomes of human placenta by treatment with phospholipase A, followed by enrichment and separation were determined. Both enzymes are strictly substrate specific. The most active substrate of one of the 17beta-HSD (fraction A) is estradiol-17beta, the other 17beta-HSD (fraction B) is sensitive to testosterone. Both NAD and NADP can serve as hydrogen transferring coenzymes, the latter giving about one-third of the initial rate of the former. With respect to the influence of temperature, different buffers and pH values, Michaelis constants (Km) with estradiol-17beta and testosterone as substrates, the solubilized and separated microsomal 17beta-HSD behave like those isolated from the cytoplasmic fraction. The two 17beta-HSD, after solubilization from the microsomal fraction of human placenta, enrichment and separation from each other, show only a little activity for the transfer of hydrogen between C17 of estradiol-17beta and C17 of androstenedione. On the other hand, intact microsomes and an integrated system prepared by recombination of the 17beta-enzymes by preincubation in phosphate buffer are able to catalyse very actively the transfer of hydrogen between estradiol-17beta and androstenedione. The effect of temperature and time on the recombination of the two enriched and separated microsomal enzyme activities and the determination of the pH-optimum of the hydrogen transfer reaction are described. Finally it is proposed that the hydrogen transfer between steroid hormones represents an aspect of the true reaction mechanism of steroid hormones: Steroid hormones function as hydrogen transferring coenzymes by forming part of a chain of hydrogen carriers.

Nach Kap.1 ist eine Aufgabe dieser Arbeit, geratetypunabhangige Uni versalbausteine zu entwickeln (Kap.4.1). Es wird jedoch nicht immer moglich und auch nicht sinnvoll sein, die dabei notwendigen Standardisierungen und Vereinfachungen auf alle zu simulierenden Gerate zu ubertragen. Ein Beispiel zur Modellbildung von geratespezifischen Bauelementen und ihrer Verknupfung wird in Kap.4.2 vorgestellt.