False-negative results by polymerase chain reaction due to contamination by glove powder

1992

The polymerase chain reaction (PCR) technique has become an important, widely employed method for the detection and quantitation of the nucleic acid sequences used in the diagnosis and monitoring of genetic and infectious diseases. Much attention has been directed at the problem of false-positive PCR results, which are generally attributed to low-level laboratory contamination of amplified sequences ("carryover"). In contrast, few investigators have commented on the somewhat less frequent, but equally problematic, false-negative PCR results. Investigation of the source of sporadic false-negative PCR reactions found that glove powder, inadvertently introduced into tubes when gloves are chang…

Hansjakob Seiler/Gunter Brettschneider (eds.) Language Invariants and Mental Operations. International Interdyscyplinary Conference held at Gummersba…

1992

Les Figures de la forme : philosophie biologique et théorie esthétique

1992

Polymerization of 3-alkylthiophenes with FeCl3

1992

We report on the mechanism of direct oxidation of 3-alkylthiophenes using ferric chloride (FeCl3) as the polymerization oxidant/catalyst to produce high molecular weight poly(3-alkylthiophenes) (P3ATs), conjugated polymers that have potential as electrically and optically active polymers. This study shows that the FeCl3 must exist in the solid state in the reaction mixture to be active as an oxidant in the polymerization of P3AT. A feasible polymerization mechanism for 3-alkylthiophene was developed on the basis of the crystal structure of FeCl3 and quantum chemical computations of thiophene derivatives. The polymerization is hypothesized to proceed through a radical mechanism rather than a…

Self-organization of hydrophobized polyzwitterions

1992

Abstract Several series of copolymers of different geometry were synthesized from zwitterionic surfactant monomers and polar non-ionic comonomers. Bulk properties were investigated by d.s.c. and X-ray scattering. The copolymers were amorphous, but exhibited superstructures up to high commonomer contents. Solubility of the copolymers was determined as a function of geometry and composition. From the results, a main chain spacer model has been derived. All water-soluble copolymers exhibited characteristic features of classical polysoaps, as shown by surface tension measurements and by solubilization of pyrene. But gradual differences depending on the polymer geometry were observed for the sol…

111 Bioluminescence analysis and numerical evaluation of ATP-synthesis by native and reconstituted membranes containing bacterial ATP-synthase

1992

ATP-synthase is a large membrane protein complex, which plays a key role in the energy metabolism of most organisms. It consists of at least eight types of subunits and can be isolated and purified from several organisms, e.g. bacteria. The enzyme couples two reversible reactions: vectorial proton transport through a membrane and synthesis of the energy rich molecule ATP. Both can be investigated with vesicles from native membranes or with reconstituted liposomes from purified ATPsynthase. The analysis is complicated because ATP-synthase catalyzes ATP-synthesis as well as ATP-hydrolysis. Furthermore the ATP level of membrane samples is influenced by adenylate kinase activities of other enzy…

A new access to 2′-amino-substituted vinylindoles as donor-activated heterocyclic dienes and their first diels-alder reactions

1992

Abstract Reactions of the 3-acylindoles 5, 10 , and 15 with α-amino-α′-diphenylphosphinoyl-substituted carbanions gave rise to the 2′-amino-substituted 3− and 2-vinylindoles 7, 12 , and 17 by way of the isolable carbinols 6 , 11 , and 16 . The heterocyclic dienes 7 , 12 , and 17 readily underwent Diels-Alder reactions with N -phenylmaleimide.

Determinants of isometric muscle strength in men of different ages

1992

Values of maximal isometric strength of five muscle groups and associated factors including occupational status, life style and health were studied in three groups of men aged from 31 to 35, 51 to 55, and 71 to 75 years. The results indicated significant differences between the age groups in isometric handgrip, elbow flexion, knee extension, trunk extension and trunk flexion strength. In the youngest group, the manual workers tended to have higher strength values in all muscle groups than the lower and higher status white collar workers, whereas among the middle-aged and oldest men the manual workers tended to have the poorest performance. Good self-rated health and the intensity of physica…

Hopping conductivity in NiO thin films

1992

Antes del Arte (1968-1969)

1992

EL GRUPO "ANTES DEL ARTE" SURGIO EN VALENCIA A PARTIR DE UNA SERIE DE REUNIONES CELEBRADAS EN CASA DEL CRITICO AGUILERA CERNI, CON EL PROPOSITO DE REVITALIZAR EL ARTE GEOMETRICO POR EL QUE YA SE HABIA INTERESADO EL GRUPO "PARPALLO", CREADO EN VALENCIA A FINES DE 1956. LA TRAYECTORIA HISTORICA DEL GRUPO TRANSCURRIO ENTRE 1968 Y 1969, DEJANDO MUESTRA DE SUS PRINCIPIOS ARTISTICOS EN TRES EXPOSICIONES (VALENCIA, MADRID Y BARCELONA). LA DISOLUCION DEL GRUPO SE PRODUJO DE FORMA PAULATINA POR EL ABANDONO DE SUS MIEMBROS (ABC/LAG).

Ludis Bērziņš (1870-1965): biobibliogrāfiskais rādītājs

1992

Biobibliogrāfiskajā radītājā ietverti Luda Bērziņa - teologa, dzejnieka, literatūrzinātnieka un skolotāja dzīves laikā publicētie darbi, kā arī literatūra par viņu.

Actualidad bibliográfica sobre la familia.

1992

El artículo recoge una selección bibliográfica sobre la familia.

Les aventures de Sherlock Holmes : organisation et utilisation de l'espace

1992

Pour voir l'article en ligne, aller sur le site de la revue Mappemonde: http://mappemonde.mgm.fr/; National audience

On the regularity of the partial {$O\sp *$}-algebras generated by a closed symmetric operator

1992

Let be given a dense domain D in a Hilbert space and a closed symmetric operator T with domain containing D. Then the restriction of T to D generates (algebraically) two partial *-algebras of closable operators (called weak and strong), possibly nonabelian and nonassociative. We characterize them completely. In particular, we examine under what conditions they are regular, that is, consist of polynomials only, and standard. Simple differential operators provide concrete examples of all the pathologies allowed by the abstract theory.

Photochemical cyclization of some aldehyde thiosemicarbazones

1992

The photochemical behaviour of some substituted aldehyde thiosemicarbazones 1a-k has been investigated in methanol at 254 nm. Thiosemicarbazones of glyoxil methyl ester 1a-f cyclized to furnish the 3-thioxo- 1,2,4-triazin-5-one 2 ring system. The remaining thiosemicarbazones 1g-j gave 1,2,4-triazoline 4 derivatives.

Chemistry of defensive secretions in nymphs and adults of fire bug , Pyrrhocoris apterus L.(Heteroptera, Pyrrhocoridae)

1992

International audience; The defensive secretions from the nymphs and the adults of both sexes in P. apterus were chemically investigated. Forty components were identified from the nymphal posterior dorsoabdominal glands and 35 from the adult metathoracic glands of both sexes. Within the 43 identified chemicals, we found 23 aldehydes, five saturated hydrocarbons, five alcohols, three ketones, three lactones, two terpenes, one phenol and one ester. Thirteen of these compounds had never been reported within the Heteroptera. Whereas eight components are specific to the nymphs, methyl pentenal, (E)-2-hexenol, and heptadecanal are the only adult-specific components. The biological role of all the…

Transporte óseo

1992

El tratamiento de las grandes pérdidas de sustancia ósea, es uno de los problemas que más dificultades ha planteado al cirujano ortopédico. Las técnicas de aporte masivo de injerto han resuelto de forma sitisfactoria este gran problema. Es en estos casos donde el método de Ilizarov alcanza su mayor espectacularidad.

Lacustrine profundal meiobenthos as an environmental indicator

1992

Organic loading and eutrophy is indicated at profundal depths by large numbers of resting copepodid stages of cyclopoid copepods, by the occurrence of the naidid oligochaete species, Amphichaeta leydigii and Specariajosinae, and the harpacticoid species Canthocamptus staphylinus, and by a low meiobenthos/ macrobenthos biomass ratio. An oligotrophic environment is indicated by the occurrence of the aeolo-somatid oligochaetes Aeolosoma quaternarium, A. hemprichi and Rheomorpha neiswestnovae, the naidid oligochaete Chaetogaster langi and the harpacticoid species Attheyella crassa and a high meiobenthos/ macrobenthos biomass ratio.

La retención a cuenta en el ordenamiento tributario español

1992

Utilización y clasificación del juguete como elemento estimulador del pensamiento científico en situaciones educativas formales y no formales

1992

Ventrikuläre Assistenz mit Zentrifugalpumpen beim Postkardiotomie-Low-output-Syndrom

1992

Im Juli 1986 wurde an der Klinik fur Herz-, Thorax- und Gefaschirurgie der Universitat Mainz erstmalig in der Bundesrepublik Deutschland erfolgreich die extrakorporale Kreislaufassistenz mit Zentrifugalpumpe bei einem Patienten mit therapierefraktarem Postkardiotomie-Low-output-Syndrom eingesetzt. Von 7/86 bis 12/90 wurde dieses Verfahren bei insgesamt 12 Patienten — oder 0,52% von insgesamt 2321 — mit Hilfe der Herz-Lungemaschine (HLM) am offenen Herzen operierten Patienten angewandt. Wahrend dieses Zeitraums wurde die intraaortale Ballongegenpulsation als ausschliesliche oder primare mechanische Kreislaufhilfe bei 60 Patienten — oder 2,6% — eingesetzt, so das die Gesamtinzidenz des postop…

A Positive Definite Advection Scheme for Use in Long Range Transport Models: Extension to Monotonicity

1992

Numerical modeling of atmospheric transport processes requires the solution of the continuity equation for prognostic variables such as momentum, heat, water vapor, liquid water or chemical species of the atmosphere. Although in the literature many advection schemes are known to solve this problem (Lax and Wendroff 1964, Crowley 1968, Tremback et al. 1987, Bott 1989a,b), these algorithms show different disadvantages, which sometimes yield undesirably poor numerical results. For instance, the upstream method is known to produce large numerical diffusion. The higher order versions of the advection schemes of Tremback et al. (1987) are much less diffusive. Unfortunately, the schemes are not po…

MEASUREMENT OF TAU BRANCHING RATIOS

1992

著者人数：112名

Multiplicity fluctuations in hadronic final states from the decay of the Z0

1992

An analysis of the fluctuations in the phase space distribution of hadrons produced in the decay of 78829 Z0 has been carried out, using the method of factorial moments. The high statistics collected by the DELPHI experiment at LEP during 1990 allowed studies of the event sample both globally and in intervals of p(t) and multiplicity, and for different jet topologies and for single jets. A large contribution to the factorial moments of the one-dimensional data on rapidity with respect to the event axis comes from hard gluons. Details of factorial moments in two and three dimensions are presented. Influences of resonance decays have been studied by Monte Carlo simulation: one-dimensional fac…

Myocardial Protection by Retrograde Cardioplegic Perfusion in the Presence of Acute Coronary Artery Obstruction: An Experimental Study

1992

To investigate retrograde delivery of cardioplegic solutions as a means of enhancing myocardial protection in the presence of coronary artery occlusion, a two-part experimental model was devised. In part 1 (in vitro) the possibility of retroperfusing the entire myocardium during acute occlusion of the left anterior descending artery (LAD) was assessed. In part 2 (in vivo) acute LAD occlusion was performed in dogs, and during 2 hours of aortic cross-clamping crystalline cardioplegic solution was infused at 20-minute intervals. In group I the infusion was antegrade, via the aortic root, and in group II it was retrograde, via the coronary sinus. Thereafter the LAD snare was released and the do…

Sensorial analysis by "sniffing"

1992

chap. 18; National audience

Geografía i control del territori: El coneixement i la defensa del litoral valencià al segle XVI: L'enginyer Joan Baptista Antonelli

1992

En este articulo se revisa y analiza un informe del ingeniero italiano Juan Bautista Antonelli en el año 1563 sobre la defensa del litoral valenciano. Este informe se inscribe en un más amplio contexto histórico de conocimiento del territorio como paso indispensable para su control por el poder real. La importancia del informe de Antonelli radica no sólo en su descripción del litoral valenciano a mediados del siglo XVI, sino en su contribución a la extensión de la idea moderna de control del territorio y su relación con la nueva forma de entender la guerra. Al mismo tiempo, se comentan otras actuaciones en el Mediterráneo contemporáneas realizadas en el antiguo reino de Valencia.

Aprendizaje estratégico y competencia de mercado en modelos de duopolio

1992

Recent progress in understanding cholinergic function at the cellular and molecular levels

1992

Cholinergic transmission can claim to be the first form of chemical neurotransmission to be investigated by pharmacological and electrophysiological methods and the first in which both the transmitter and its receptor have been isolated and characterized. One reason for this is that neuromuscular transmission is cholinergic and the neuromuscular junction (especially that of frogs) is a readily investigated synapse in which responses are recorded by a muscular twitch — something which can be appreciated by direct observation and which does not require sophisticated equipment. Another is that in the form of the electric organs of strongly electric fish Nature has provided a tissue embryologic…

Sulla natura giuridica delle pronunzie della Corte Costituzionale

1992

Desde las escuelas a la Universidad

1992

Desde las escuelas a la Universidad

Conexionismo y el epifenomenalismo de lo mental

1992

[SPA] En este artículo discuto una serie de argumentos presentados por J. Fodor, Z. Pylyshyn y B. McLaughlin donde se defiende que el surgimiento de los modelos conexionistas no representa realmente una amenaza para la hipótesis del lenguaje del pensamiento, dado que esos modelos no pretenden dar cuenta de la sistematicidad del pensamiento ni de la eficacia causal de las propiedades mentales. A lo largo del artículo intento mostrar, sin embargo, que los argumentos mencionados no aciertan a excluir la posibilidad de dar cuenta, dentro de un modelo conexionista, de la sistematicidad y la eficacia causal de lo mental. Este hecho afectaría ciertamente a los mejores argumentos en defen…

Sébastien Valdenaire et les copistes d'Hérival

1992

International audience

Functional Calculus and Fredholm Criteria for Boundary Value Problems on Noncompact Manifolds

1992

A Boutet de Monvel type calculus is developed for boundary value problems on (possibly) noncompact manifolds. It is based on a class of weighted symbols and Sobolev spaces. If the underlying manifold is compact, one recovers the standard calculus. The following is proven:

Selektivit�tsstudien: OH-, NH- und SH-gruppenspezifische Reagentien - ihre Anwendung in der organischen Analytik und als Schutzgruppen in der Synthese

1992

Selectivity: OH-, NH- and SH-Groupspecific Reagents. The Application in Organic Analysis and as Protective Groups Phosphylhalides and -pseudohalides R1R2P(O)X (X = Cl, F, CN, N3, OC6H4NO2(p)) reactdepending on X- with a different selectivity with OHNH- and SH-groups. Vinylsulfones ArSO2CH = CH2 are SH-selective. Silanes R3SiH are OH-selective. By exchange of one ligand bound on P, SO2 or Si by the 5-dimethylamino resp. the 5-methoxynaphthalinogroup reagents are formed, which combine group selectivity with fluorescence. The fluorescence is quenched if a ligand or the leaving group is substituted by a NO2-group. The fluorescence appears again if after the group selective fixation the ligand w…

Classification of the hadronic decays of the Z$^0$ into b and c quark pairs using a neural network

1992

A classifier based on a feed-forward neural network has been used for separating a sample of about 123 500 selected hadronic decays of the Z 0 , collected by DELPHI during 1991, into three classes according to the flavour of the original quark pair: u u +d d +s s (unresolved), c c and b b . The classification has been used to compute the partial widths of the Z 0 into b and c quark pairs. This gave Γ c c /Γ h = 0.151 ± 0.008 ( stat. ) ± 0.041 ( syst. ) , Γ b b /Γ h = 0.232±0.005 ( stat. )±0.017 ( syst. ) .