showing 36 of ~574560 from 574555 documents
Vergleichende Raster-Elektronenmikroskopische Untersuchungen von Knochenzementen mit unterschiedlichen Kontrastmittelbeimengungen
1977
Rasterelektronenmikroskopisch wurden die Bruchflachen von Knochenzementproben untersucht, die bei Zugfestigkeitsuntersuchungen entstanden waren und denen zwei verschiedene Konzentrationen der beiden gebrauchlichen Kontrastmittel Bariumsulfat (CMW Bone-Cement®) oder Zirkondioxid (Palacos®) zugesetzt worden waren.
Linkage of C4 and C4 deficiency to BF and GPLA
1977
The C4, Bf, and GPLA phenotypes of homo- and heterozygous C4-deficient guinea pigs were studied. The electrophoretic patterns suggest that the deficiency in circulating C4 results from an impaired structural gene, allelic to the C4F, C4S, and C4S1 alleles at the C4 locus. In family studies, support for linkage of C4 and Bf to theGPLA system was obtained. The defective gene appears to be the fourth allele, which is rare, in the polymorphism of the fourth component of guinea pig complement.
Three nuclei n.m.r. spectroscopy of dimethoate compounds. A large solvent effect on the31PSC1H vicinal coupling
1977
Proton, phosphorus and carbon magnetic resonance spectra of dimethoate, dimethoxon, des-N-methyldimethoate, ω-hydroxydimethoate, trimethyldithiophosphate and O,O-dimethyldithiophosphate in different solvents have been measured. Most of the n.m.r. parameters were characteristic of the structural environment of the corresponding nucleus and solvent-independent. However, in the amide structures dimethoate, dimethoxon, des-N-methyldimethoate and ω-hydroxydimethoate the 31PSC1H vicinal coupling showed an unusually large solvent effect of a 2.3 to 6.5 Hz decrease when CDCI3 was replaced by acetone-d6 or DMSO-d6.
Polymere ester von säuren des phosphors, 6. Ringöffnende polymerisation cyclischer phosphite und phosphonite durch michaelis-arbuzov-reaktion.–Theori…
1977
The hypothesis of Harwood and Patel, suggesting for the polymerization of 2-phenyl-1,3,2-dioxaphospholane a type of insertion reaction to explain the formation of ethylenediphosphinic ester structures besides the normal 2-hydroxyethyl(phenyl)phosphonic ester structures is extended to similar monomers and its theoretical consequences are examined. It is shown that in such a system mutual transformations between ω-hydroxyalkyl-P-acid and alkylenedi(P-acid)structures should occur, establishing a dynamic equilibrium and leading to a sort of azeotropic polymer, in which only one unique composition is kinetically stable. Equations relating to different kinetic parameters are deduced.
Time and Temperature Dependence of Macro-ion-Macro-ester Equilibrium in the Cationic Polymerization of Tetrahydrofuran by HOSO2F
1977
Abstract Reactivity and equilibrium of two active species-tertiary oxonium ion (TOI) and superacid ester (SAE)-in the system of cationic polymerization of tetrahydrofuran (THF) initiated by fluorosulfonic acid (FSO3H) in dichloromethame has been studied. In the given system, it was found that TOI is mainly responsible for the polymerization at the initial stage; however, the cocentration of TOI decreases rapidly with the progress of polymerization and finally becomes almost untraceable. On the other hand, [SAE] monotonically increases as the polymerization proceeds. The stability of TOI appears less than that of SAE under the given reaction conditions. Results demonstrate that both the prog…
Feeding habits, post-embryonic and adult survival, mating, virility and fecundity of the predacious miteAmblyseius swirskii [Acarina: Phytoseiidae] o…
1977
The nutritional value forAmblyseius swirskiiAthias-Henriot, of eggs or crawlers ofCoccus hesperidum L.,Saissetia oleae (Olivier),S. coffeae (Walker),Pseudococcus citriculusGreen, andP. longispinusTarg.-Tozz, even with the addition of honeydew, was low; only a few young reached adulthood and the oviposition rate was negligible. However, addition of honeydew toTetranychus cinnabarinusBoisd. enhanced the oviposition rate ofAmblyseius swirskii. Honeydew was a favourite food forA. swirskii, whereas the eggs and crawlers tested were not eagerly attacked and consumed. Females and males fed honeydew ofSaissetia oleae mated readily and the females were inseminated, but fecundity was negligible.
221. Darstellung der H�ftpfannenbr�che im R�ntgenbild und am anatomischen Pr�parat
1977
Aus dem Krankengut der Unfallchirurgischen Universitatsklinik Mainz mit 310 Acetabulumfrakturen werden die vier Grund- und vier kombinierten Frakturformen des von Judet u. Letournel angegebenen KlaBifizierungBchemas, welches biomechanische, therapeutische und prognostische Aspekte am besten berucksichtigt, mit Rontgenbild und Skizze dargestellt. Um die raumliche Vorstellung zu erleichtern, werden an praparierten Modellen die jeweiligen Frakturformen demonstriert.
A model study on the nuclear photoeffect
1977
In a simple model of a spinless particle moving in a finite square well potential influences of final state Born approximation and of various approximations in the electromagnetic operators on photoabsorption differential, total and integrated cross sections are investigated. While the Born approximation is very poor in all respects, the long wave length approximation turns out to be the best and reproduces the total cross section quite well. However, appreciable deviations occur in the differential cross section at intermediate energies. The integrated cross section slightly exceeds the classical sum rule resulting from nonanalyticity of the forward compton scattering amplitude, as is disc…
1H and13C n.m.r. spectra of dichloro(trans-2-chlorovinyl)arsine
1977
Proton and carbon magnetic resonance spectra of Lewisite or dichloro(trans-2-chlorovinyl)arsine have been measured and the results are compared with the n.m.r. spectral parameters of other trans-1,2-substituted ethylenes. The coupling constants can be rationalized by substituent electronegativity. The chemical shifts show an unusually large paramagnetic effect from the AsCl2 group.
Charakterisierung (A, B)-regul�rer faserungen durch schliessungss�tze
1977
132. Experimentelle Untersuchungen �ber eine neue M�glichkeit zur operativen Versorgung von Symphysensprengungen und vorderen Beckenringfrakturen
1977
Die Symphyse und die Sacro-Iliacal-Gelenke muBen aus mechanischen uberlegungen heraus als Gelenke angesehen werden. Dabei wird die Symphyse in den beiden senkrecht zueinander stehenden Ringebenen vorwiegend auf Zug und Schub beansprucht. Das Anbringen einer Zuggurtungsplatte gleichzeitig an beide Schambeinaste fuhrt aus mechanischer Ursache zur Lockerung der Schrauben. Es wurde experimentell ein neues Operationsverfahren untersucht. Es werden 2 L-Platten an die oberen Schambeinaste angebracht. In die freien Locher der kurzen Schenkel der Platten wird eine spezielle Klemme eingehangt, die durch Nachspannen eine KompreBion von 30 kp erzeugt. Die Klemme selbst toleriert Zugbeanspruchungen von …
Polyreactions in ordered systems: Polymerization of octadecyl methacrylate in monolayers at the gas–water interface
1977
The ultraviolet-initiated polymerization of octadecyl methacrylate (ODMA, octadecyl 2-methyl-2-propenoate) as a monomolecular layer at the gas-water interface was studied. The polymerization was carried out at 27°C at the nitrogen-water interface; air inhibits the polymerization. At 27°C the ODMA monolayer exhibits three different states which were characterized by surface pressure-area diagrams and by surface potential measurements. The ODMA monolayer was polymerized under constant surface pressure in the range between 0 and 10 dyne/cm. The polymerization was followed by recording the contraction of the film. The conversion was determined by comparison of the area per monomer unit during p…
Oxygen diffusivity in tumor tissue (DS-Carcinosarcoma) under temperature conditions within the range of 20?40�C
1977
The O2 diffusion constants D and K of tumor tissue (DS-Carcinosarcoma in the rat kidney) were determined at temperatures of 20, 30, 37, and 40 degrees C. The following mean values were obtained for the conditions of 37 degrees C: D = 1.75-10(-5) cm2/s and K = 1.9-10(-5) mlO2/cm-min-atm. Within the range of 20-40 degrees C, temperature variations in tumor tissue cause changes in the O2 diffusion coefficient D of 2.0-2.5%/C and in the Krogh O2 diffusion constant K of 0.5-1.5%/C. The measured O2 diffusion constants for tumor tissue correspond to values of normal tissue with similar water content. This indicates that the insufficient O2 supply in DS-Carcinosarcoma is due not to unfavorable O2 d…
Essential role of surface-bound chemoattractant in leukocyte migration
1977
MANY chemotactic factors, usually proteins or peptides, have been isolated and studied, but little is known about the basic mechanism of leukocyte migration. This movement is termed chemotaxis if its direction is determined by substances in the cells' environment1. The chemotactic agent is assumed to convey information to the leukocytes by interaction with receptors. The subsequent sequence of events thus triggered in the cells is unknown but metabolic changes such as activation of an esterase have been reported as occurring as the cells move forward (for review see ref. 2). A role for surface-bound chemoattractant in cell locomotion was suggested by the observation that mouse fibroblasts m…
Spatial distribution of various types of bulbar respiratory neurons in the rabbit
1977
In anesthetized rabbits, the burst activity of 277 single respiratory neurons was recorded extracellularly. The neurons were classified according to their spike incidence distribution within the respiratory cycle and to their response to lung distension or collapse (alpha or beta type). About one third of the neurons found in all animals were located at the level of the caudal end of the promontorium gliosum, widely scattered over the bulbar cross-section. More rostrally the units were located within a dorsal area neighbouring the tractus solitarius, more caudally within a ventral field surrounding the nucleus ambiguus. Most of the inspiratory neurons (the most frequently encountered type) …
Isotopic composition of cattle pancreatic stones: biological and geochemical implications.
1977
Latitudinal variations of the O18/O16-ratios of carbonate and phosphate of cattle pancreatic stones parallel a similar pattern of oxygen isotope values in rain water. C13/C12-ratios were virtually identical for the 7 cases studied. Isotopic measurements of mammalian hard tissues may be used for studying short-term climatic variations through Quaternary.
F1-ATPase from Micrococcus sp. ATCC 398. Purification by Ion-Exchange Chromatography and Further Characterization. (Auto)proteolysis and Dissociative…
1977
The preparation of highly purified F1-ATPase from Micrococcus sp. ATCC 398 by application of DEAE-Sepharose CL-6B chromatography as final step is described. This enzyme consists of five subunits of different molecular weight: alpha (65000), beta (55000),gamma (35000), delta (20000), and epsilon (17000). Disc electrophoresis on 5% polyacrylamide gels removes the epsilon-polypeptide yielding an active ATPase complex with four different subunits: alpha, beta, gamma, delta. Additionally, by variation of the ionic strength delta can (partly) removed allowing the isolation by disc electrophoresis of an active ATPase complex which consists only of three different subunits alpha, beta, and gamma. I…
Further link between complement activation and blood coagulation
1977
EVIDENCE for interactions between the complement and haemostatic systems has come from two lines of research—blood platelets have been shown to interact with various complement components1–6, and more ambiguous results have been obtained with respect to the role of complement in endotoxin shock and the Shwartzman reaction7–13. We report here that the activated complement component C3b triggers a marked increase of tissue thromboplastin (factor III) activity in cultured human monocytes. Differential counting and nonspecific esterase staining14 of the final preparations regularly revealed more than 85% monocytes.
Modulation by oxotremorine and atropine of acetylcholine release evoked by electrical stimulation of the myenteric plexus of the guinea-pig ileum
1977
1. The effects of oxotremorine and atropine on the release of acetylcholine from longitudinal muscle strips of the guinea-pig ileum stimulated at frequencies between 0.1 and 3 Hz in the presence of eserine were investigated. In control experiments the acetylcholine output per stimulus declined with increasing frequencies of stimulation. 2. Oxotremorine inhibited the release of acetylcholine in a concentration-dependent fashion. At a concentration of 10−6 M oxotremorine, the release evoked by 0.1 Hz was reduced by 54%. With increasing frequencies of stimulation the inhibitory effect of oxotremorine became smaller. 3. Atropine enhanced the output of acetylcholine evoked by electrical stimulat…
DMPP and the adrenergic nerve terminal: mechanisms of noradrenaline release from vesicular and extravesicular compartments.
1977
DMPP (1,1-dimethyl-4-phenylpiperazine) in various concentrations between 1.6×10−6 M and 6.2×10−5 M was infused into isolated rabbit hearts to study the neuronal release and uptake of noradrenaline.
Formation of basement membrane in extracapillary proliferates in rapidly progressive glomerulonephritis
1977
In the extracapillary proliferations (crescents) of the glomeruli in glomerulonephritis, basement membranes appear and in addition "secretory bodies" are formed in the cisternae of the rough endoplasmatic reticulum. The findings permit the conclusion that proliferated visceral epithelial cells are involved in the crescent formation to a greater extent than previously assumed.
Precise energies of gamma rays from the 230Th and 228Th decay
1977
Abstract Energies up to 300 keV of prominent gamma rays from the decay of 230 Th, 228 Th and some of the 228 Th descendants have been precisely measured by use of Ge(Li) detectors.
Die kopplungskonstanten nJ(SnC) und n+1J(SnH) ineinigen verbindungen mit der tetramethyldizinngruppe
1977
Abstract Comparison of data on seven compounds containing the group tetramethylditin shows a variation in the coupling constants depending on the lone pair electrons of the substituents.
Effect of endurance training on the capacity of red and white skeletal muscle of mouse to oxidize carboxyl-14C-labelled palmitate.
1977
Three groups of mice were trained for 1, 4 and 5 months according to different running programs on a motor driven treadmill and the fatty acid oxidation capacity (FAO) and the activities of some enzymes of energy metabolism (cytochrome c oxidase, malate dehydrogenase, triosephosphate dehydrogenase, and lactate dehydrogenase) were determined from m. quadriceps femoris (MQF). Endurance training increased the FAO [5-month training 4 days/week, 30 min/day 22% (p less than 0.05); 1-month training, 7 days/week, 150 min/day 37% (p less than 0.001); 4-month training, 5 days/week, 60 min/day 24% (p less than 0.05)]. The activities of cytochrome c oxidase and malate dehydrogenase increased approx. 30…
Chemistry of the μ-hydridobis(pentacarbonylchromium(0)) species
1977
Abstract Reactions of the potassium and tetrabutylammonium derivatives of Cr 2 H(CO) 10 − , with N-donor bidentate ligands such as 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy) have been investigated. A coordination compound of general formula K[Cr 2 H(CO) 10 (phen) 3 ] is the most stable product from the reaction of the former with phen, but under certain conditions a 1 2 adduct may also be isolated. The analogous reaction with bpy leads to a single labile adduct, K[Cr 2 H(CO) 10 (bpy) 2 ]. (C 4 H 9 ) 4 N[Cr 2 H(CO) 10 (phen)] is formed by interaction of the latter derivative with phen, but bpy does not give the analogous adduct.
Elastic electron scattering from the multipole moment distributions ofMg25
1977
Drug-induced variations of the renin-angiotensin-aldosterone system in rats. I. Diuretics.
1977
Summary Groups of 10 rats were treated with diuretics (furosemide, hydrochlorotiazide, spironolactone, triamterene) under conditions of high or low plasma renin activity (PRA) brought about by administering distilled water or saline load, respectively. PRA, plasma aldosterone levels, urine aldosterone concentration as well as diuresis and Na+ and K+ excretion were
Long-Term Followup of Children with Colon Conduit Urinary Diversion and Ureterosigmoidostomy
1977
Sixty-four children underwent colon conduit urinary diversion because of a neurogenic bladder owing to myelomeningocele and 39 children required a ureterosigmoidostomy because of bladder exstrophy. The average length of followup was 4.6 years after colon conduit and 5.6 years after ureterosigmoidostomy. Colon conduit diversion was secondary in 3 children and ureterosigmoidostomy was secondary in 5. Of the children with a colon conduit 9.4% and of those with ureterosigmoidostomy 12.8% had postoperative surgical complications. Late surgical complications were encountered after colon conduit in 14.5% and after ureterosigmoidostomy in 20%. Of the children with normal renal function preoperative…
The mutagenicity of MCPA and its soil metabolites, chlorinated phenols, catechols and some widely used slimicides in Finland
1977
Master curves of viscoelastic behavior in the plastic region of a solid polymer
1977
Stress relaxation and creep tests following strain ramps were made on Mylar, both above and below the yield stress. The ramp velocity was varied over a 40-fold range. All data exhibit nonlinear viscoelastic behavior. However, those obtained above the yield point, i.e., in the plastic region, could be reduced to single master curves for both the creep and the relaxation tests by means of a simple time shift factor. This factor is inversely proportional to the strain rate existing just prior to the test.
Drug induced variations of the renin-angiotensin-aldosterone system in rats. II. Antihypertensives
1977
Summary Groups of male rats were treated with antihypertensive drugs (alpha-methyl-dopa, clonidine, propranolol, reserpine, diazoxide) which were administered under conditions causing the onset of high plasma renin activity (PRA) and high plasma and urine aldosterone levels, i.e. together with distilled water load (5% of body weight). Alpha-methyl-dopa and propranolol, which fail to significantly alter PRA and plasma aldosterone levels when administered without distilled water load, cause a marked decrease of plasma and urine aldosterone levels and of PRA when administered together with distilled water load, while diazoxide, and reserpine cause a marked increase of these values. Clonidine c…
Über die Verbreitung von Flavonoiden bei pleurokarpen Laubmoosen I. Apigenin-7-rhamnoglucosid bei Hylocomium splendens (Hedw.) Br. eur.
1977
Summary 15 species of pleurocarpous mosses have been investigated as to their content of flavonoids. Flavonoid tests on 14 species have given negative results. Only one species, Hylocomium splendens , contains one flavonoid. It was purified by means of paper chromatography and is by chromatography and absorption spectrum identical with rhoifolin (apigenin-7-neohesperidoside). Partial acid hydrolysis yields apigenin-7-monoglucoside and rhamnose, quantitative hydrolysis apigenin, rhamnose and glucose. They were identified by comparison with authentic samples.
Effect of polybrominated biphenyls on bromobenzene lethality in mice.
1977
Polybrominated biphenyls (PBBs) are inducers of hepatic microsomal cytochrome P450 and P1 450 in rats and mice. The purpose of this study was to determine, in mice, the effect of PBBs on the lethality of the hepatotoxin bromobenzene. Female NMRI mice were administered a single ip injection of 150 mg/kg PBBs and other mice received phenobarbital (PB), 100 mg/kg daily for 3 days, or 3‐methylcholanthrene (MC), 20 mg/kg daily for 3 days. At 24 hr after PB or MC and 24, 48, and 96 hr after PBBs animals received 3,150 mg/kg bromobenzene ip (LD85) and the time to death was recorded. Both PB and MC enhanced bromobenzene lethality and decreased the median time to death (LT50) from 23 hr in controls …
false
1977
The thermal behavior of cycloalkanes (CH2)n with 12 ≤ n ≤ 84 prepared by metathesis reaction of cyclododecene, GPC separation of the oligomers, and hydrogenation has been investigated. The molar enthalpies of fusion being lower by a certain amount than those of the corresponding n-alkanes are a linear function of the chain length n. The entropy of fusion per CH2 increases with chain length in a not-linear mode (when plotted vs. 1/n). The melting points of the cycloalkanes are lower than those of the corresponding n-alkanes, the difference becoming smaller with increasing chain length.
Splenic respiratory gas exchange and glucose uptake in patients with splenomegaly in hypersplenism and Hodgkin's disease.
1977
Blood samples are taken from the splenic artery, vein and pulp of patients suffering from Hodgkin's disease (n=10) or hypersplenism (n=7) and undergoing splenectomy. In these samples, the relevant parameters of the respiratory gas exchange as well as glucose and lactate concentrations are determined. In hypersplenism (mean splenic wet weight: 543 g) the mean oxygen consumption of the splenic tissue amounts to 0.9 ml O2/100 g/min taking into account a mean splenic blood flow of 80 ml/100 g/min. The glucose uptake and the lactate release are 9 mg/100 g/min and 5.5 mg/100 g/min, respectively. These values are in close agreement with the results obtained in the normal and undisturbed spleen in …
Les aides aux étudiants en France
1977
International audience