showing 36 of ~574560 from 574555 documents
Thin-layer chromatography of phenoxyacetic acid herbicides
1981
Free-atom—metal shifts in theM4,5N4,5N4,5Auger spectra of Ag, Cd, In, Sn, Sb, and Te
1981
High-Spin States in204Bi and the Question of Many-Nucleon Configuration Mixing
1981
The properties of high-spin levels in 204Bi have been studied using conventional in-beam γ-ray and conversion-electron spectroscopy on the products of the reactions 205Tl(α, 5n) 204Bi and 203Tl(α, 3n) 204Bi. The yrast cascade is followed to a 19+ level at 3808 keV and several non-yrast levels in the spin interval J = 9-16 are reported. The energies of the levels in 204Bi were calculated within the shell-model frame of multi-nucleon states, and the agreement is found to be good. A previously reported T1/2 = 1 ms isomeric state is shown to have a main configuration πh9/2ν(j-2)0+(i13/2-2)12+f5/2-1 and a spin-parity 17+. The configuration mixing for the neutron-hole components of the wave funct…
Versuche zur umsetzung von methylendiphenolen mit glucosederivaten und zur kondensation von O-phenylglucosidderivaten
1981
Attempts to apply known methods of glucosidation to oligo[(hydroxyphenylene)methylene]s were not satisfying. The reaction of 4,4'-dimethyl-2,2'-methylenediphenol (1a) with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide gave a monoglucoside in 11% yield. A second attempt, the condensation of suitable O-phenylglucoside derivatives was unsuccessful. From a series of O-phenylglucosides (4) only 4-(2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyloxy)benzylbromide could be condensed with O-(4-hydroxymethylphenyl)-2,3,4,6-tetra-O-acetylglucopyranose to the corresponding diglucoside of 4,4'-oxydimethylenediphenol (7). Condensation reactions of the O-phenylglucoside 4k, to obtain an O-glucosidized poly[…
Effects of age and prolonged running on proteolytic capacity in mouse cardiac and skeletal muscles.
1981
Male NMRI-mice, aged 3, 6, 9, and 12 months, were made to run for a period of 4 4 at a speed of 13.5 m/min on a motor-driven treadmill, 5 days after exertion, selected enzymatic estimates of acid and alkaline proteolytic as well as energy metabolic capacities were analyzed from the cardiac muscle and from the red and white parts of m. quadriceps femoris (MQF). The activities of alkaline and myofibrillar proteases increased most considerably in skeletal muscles with age. Cathepsin D and beta-glucuronidase activities were less affected in both muscles. Prolonged running increased the activities of cathepsin D, dipeptidyl aminopeptidase I and beta-glucuronidase in the white and, especially in …
Determination of toxic elements by cathodic-stripping-voltammetry
1981
The DPCSV determination of arsenic, selenium and tellurium in the sub-ng/ml range is discussed. After electrolytic deposition of the elements as intermetallic compounds with copper on the electrode surface, the determination is carried out by cathodic stripping. The simultaneous determination of selenium and tellurium or of selenium and arsenic is possible. Problems which occur in the application of these methods are discussed.
The Hauran Conflicts of the 1860s: A Chapter in the Rural History of Modern Syria
1981
This paper examines the relatively neglected rural history of Syria. It concentrates on the Hauran, a dry-farming region of hills and plains south of the Damascene oasis between the northern Jordan's tributaries and the eastern desert. Although the Hauran is today no longer a region of primary economic importance to Syria as it once was, it is of historical interest because it was the very first of greater Syria's outlying rural zones to be integrated into the developing modern Middle Eastern economy.The Hauran is, moreover, of comparative interest because it held a position in Syria's political economy then which bears many resemblances to the positions held by younger hinterland regions n…
The role of the substantia nigra in the control of amygdaloid paroxysmal activity.
1981
AbstractBoth in acute and chronic cats, focal paroxysmal activity evoked in the ventro-basal complex of the amygdala has been inhibited by substantia nigra conditioning stimulation, to a greater extent, than by caudate nucleus activation. Injection of kainic acid into substantia nigra resulted in the disappearance of the caudate inhibition. It is suggested that the final control, exerted by the striatum on the amygdaloid seizures, occurs by means of the substantia nigra.
Optical studies on interaction of biliary contrast agents with native and modified human serum albumin.
1981
The interaction of two homologous series of biliary contrast agents with native human and bovine serum albumin and with modified human serum albumin was investigated using circular dichroism and equilibrium dialysis. For most derivatives, extrinsic Cotton effects were observed for the interaction with both albumins. In some cases, these effects were strongly affected by only small changes in the chemical structure of the drugs. These large differences in extrinsic Cotton effects can be explained by definite effects of the chemical structures on the binding site selectivity of some drugs. For example, iopodate preferentially binds to the warfarin binding site of human Scrum albumin, while an…
Die Crozat-apparatur im Rahmen der kieferorthopädischen Spätbehandlung
1981
Auf Grund klinischer Erfahrungen werden Vor- und Nachteile derCrozat-Apparatur diskutiert. Die Indikation dieser Methode wird auf einen relativ kleinen Kreis von Spatbehandlungen eingeschrankt.
Analyse et confrontation des résultats de quelques enquêtes longitudinales
1981
International audience
false
1981
Elution curves on spherosil gels in pure and mixed eluents of poly(dimethylsiloxane), PDMS, and poly(methyl methacrylate), PMMA, as well as those of polystyrene, PS, just for comparison, have been determined. In a general way, PDMS elution volumers fit to those of PS, whereas PMMA elution curves shift to higher retention volumes. The differences in retention volumes between the different polymeric solutes have been interpreted in terms of differences in polymer-gel and polymer-solvent interactions. Hydrogen-bonding seems to be the main contribution to solute-substrate interactions.
Partial spatial equilibria with fuzzy constraints
1981
It is implicitly accepted by spatial economic analysis that the economic behaviour of agents located in given spaces (market areas, regions, etc.) is precise, that is to say, their behaviour is such that a possible action (consumption, production) is, or is not, preferable to another. In otherwords, economic agents are assumed to make accurate economic calculations and optimise the objective functions under strict constraints of resource limitation. These objective functions have clearly defined arguments and well-controlled parameters.
Thin-layer chromatography of chlorinated catechols on a silica gel 60 layer
1981
Management of complications after operations for acute pancreatitis.
1981
After early operation in 49 patients and delayed operation in 114 patients, all with acute hemorrhagic-necrotizing pancreatitis, 65% of patients developed local or general complications. Local complications were abscesses, peritonitis, bleeding, gastrointestinal fistulae or stenoses, and external pancreatic fistulae. Their cause can be traced to the large wound cavity with the tryptic wound surface as well as residual necrosis. The general postoperative complications were shock, acute renal failure, cardiorespiratory insufficiency, gastrointestinal bleeding, ileus, coagulopathy, and sepsis. These may have resulted from the local complications, or may even have been present before operation.…
On the magnetic dipole moment of the153Tb ground state
1981
Temperature dependence of the angular distribution anisotropy of the 212·0 keV gamma-ray following the decay of153Tb oriented in a gadolinium host was measured at temperatures from 16 to 70 mK. Magnetic dipole hyperfine splitting parameter a0 for153Tb(Gd) and magnetic dipole moment of the153Tb ground state were estimated to be ¦a0¦≧1·2×10−5 eV and ¦μ¦≧≧3·1 nuclear magnetons, respectively.
Conductance of potassium halides near the temperature of maximum density of water
1981
The conductances of dilute aqueous solutions of KCl, KBr, and KI have been measured over the temperature range 2 to 8°C and have been analyzed by the Fuoss-Hsia equation. The ionic Walden products at infinite dilution have been discussed in terms of local viscosity. The temperature dependence of these products suggest that near the temperature of maximum density of water, the structure-breaking ability of these ions changes in a regular way.
Determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in goat milk and tissues by glass capillary gas chromatography and medium resolution mass fragme…
1981
Abstract An analytical method has been developed for the study of the elimination of 2,3,7,8-tetrachlodoribenzo-p-dioxin (TCDD) by lactation and its determination in various tissues of goat. The method is based on the alkaline hydrolysis of milk, liver, fat, muscle, blood, faeces and urine samples, extraction with n-hexane, treatment with sulphuric acid-saturated silica gel, chromatographic clean-up on silica gel and alumina micro-columns, and glass capillary gas chromatography—medium resolution mass fragmenography (resolution 2000). 1,2,3,4-Tetrachlorodibenzo-p-dioxin is used as the internal standard, the concentration of TCDD being determined from the calibration curve calculated from the…
Synthesis of heat-shock proteins in developing sea urchins.
1981
Heating sea urchin embryos at 31°C greatly reduces the synthesis of the bulk proteins, whereas it highly stimulates the synthesis of some new proteins, the main ones being two closely migrating proteins of about 70,000 daltons. The production of heat-shock proteins is obtained only if the embryos are heated after hatching. Stages which produce heat-shock proteins survive heating, whereas earlier stages, not producing heat-shock proteins, do not survive. Heat-shock proteins are not produced in the presence of actinomycin D.
Determination of alinidine in human plasma by high-performance liquid chromatography.
1981
Chemistry of ?-hydridobis[pentacarbonylchromium(0)] species. Part III. Redox reactions with mercury(II) compounds and iodine
1981
[Cr2(CO)10(μ-H)]− undergoes ready hydride substitution on reaction with HgX2 (X = Cl, Br, I or SCN) or with iodine in acetone, yielding [Cr2(CO)10(μ-X)]− complex species which can be converted quantitatively into [Cr(CO)5X]− anions by reactions conducted in the presence of an excess of X−.
false
1981
Dynamic-mechanical and dielectric measurements have been performed with some polycarbonate samples. In one set of experiments care was taken to avoid any absorption of moisture. In other sets of experiments, samples were exposed to atmospheric humidity and to boiling water. The glass transition temperature was found to be highly affected by the absorption of water and by the test conditions. Dynamisch-mechanische und dielektrische Messungen wurden an Polycarbonatproben durchgefuhrt. In einer Versuchsserie wurde die Absorption von Wasser vollstandig vermieden, in weitern Versuchen wurden die Proben der Luftfeuchte bzw. kochendem Wasser ausgesetzt. Die Glasubergangstemperatur wurde durch das …
Frattiniduale und Fittingklassen endlicher auflösbarer Gruppen
1981
Activation of the alternative pathway of complement: efficient fluid-phase amplification by blockade of the regulatory complement protein β1H through…
1981
Current concepts of activation of the alternative pathway of complement (APC) focus on the central role of an amplification mechanism triggered by C3b which is covalently bound to the surfact of activating substances. Using sulfated polyanions as model substances, an efficient fluid-phase activation of complement is demonstrated in contrast to solid-phase activation. It is shown that particulate high-molecular weight sulfated polyanions are capable of reversible binding the guinea pig and human regulatory protein beta1H. This fixation leads to an extensive activation of C3 and factor B because the regulatory function of beta1H is blocked in the fluid-phase C3b-dependent amplification system…
Arachnid oenocytes: ecdysone synthesis in the legs of harvestmen (Opilionidae).
1981
Cells measuring up to 130 microns have been found in the proximal segments of the femora of all four pairs of walking legs in various species of harvestmen (Phalangium opilio, Leiobonum limbatum, Opilio parietinus, and Opilio ravennae). These cells exhibit all the fine-structural characteristics of insect oenocytes, in particular the conspicuous agranular endoplasmic reticulum. Radioimmunoassay after in vitro incubation of these cells has demonstrated the synthesis of alpha- and beta-ecdysone. These ecdysteroids have been found in the ovaries and tergites of the opisthosoma as well as in the oenocytes.
Two-second standardization of the Harpenden Caliper.
1981
Glass capillary gas chromatography of methyl, methyl 2-chloro and chloromethyl esters of C2-C20n-carboxylic acids
1981
Geochronology of an archaean tonalitic gneiss dome in Northern Finland and its relation with an unusual overlying volcanic conglomerate and komatiiti…
1981
Archaean gneiss-greenstone relationships are still unresolved in many ancient cratonic terrains although there is growing evidence that most of the late Archaean greenstone assemblages were deposited on older tonalitic crust.
Response of human ventricular heart muscle to histamine
1981
Choline inhibits acetylcholine release via presynaptic muscarine receptors
1981
The effect of exogenous choline on the outflow of 3H-acetylcholine evoked by field stimulation was studied on the myenteric plexus-longitudinal muscle preparation of the guinea pig. Choline at concentrations of 100 microM and higher depressed the evoked outflow of 3H-acetylcholine in a concentration-dependent manner. The EC50 for the inhibitory action was 300 microM. Scopolamine (10 nM) antagonized the effect of choline which indicates that the inhibition of 3H-acetylcholine outflow is mediated by muscarine receptors. The findings imply that choline at high concentrations does not improve cholinergic synaptic neurotransmission in tissues that are endowed with presynaptic muscarine receptors…
Nitroblue-tetrazolium test for the functional evaluation of phagocytic cells: a critical analysis of the methodology.
1981
The reduction of NBT to formazan has been suggested as an indicator of the reduction potential of biological systems. An increase in the amount of reduced formazan reflects the activation of the hexose monophosphate shunt of phagocytes cultivated in vitro, as a result of cellular stimulation by chemical or biological factors, or during phagocytosis. This phenomenon has been widely used for the determination of activated phagocytes by different methods. However, the technical limitations of these methods have not been evaluated carefully. In the investigations presented here three solvents for formazan, pyridine, dioxane and dimethyl-formamide, have been tested for their suitability as extra…
Aptitudes et classes sociales : accès et succès dans l'enseignement supérieur
1981
Mingat Alain. — Aptitudes and Social Classes : Access to and Success in Higher Education. In this paper, two types of social selection in education are considered. In the first place, the proportions in higher education in various social groups are compared to the distribution of measured intelligence in these groups. The adequacy of measurements of intelligence is not discussed, but account is taken of the fact that IQ measures are used in educational institutions for the purposes of assessment. It is noted that if entry into higher education were dependent entirely on the achievement of high IQs, the proportions of workers' and farmers' children in higher education would be far greater th…
Antimony-121 mössbauer and infrared spectral study on halophenylantimonate(III) Compounds
1981
Abstract The synthesis and the 121 Sb Mossbauer and infrared spectra of halophenylantimonates(III) M[PhSbX 3 ] (M Me 4 N, Ph 4 As;X Cl, Br, I) are reported, and the spectral data are discussed and compared with those of SbX 4 and other related systems. The results are in accord with the participation of the antimony 5s electrons in the SbPh bond. In the interpretation of the electric field gradient, the contributions to V zz from both the lone pair and the SbPh bond electron densities are assumed to be dominant.
Percutaneous Stone Manipulation
1981
Percutaneous stone manipulation by direct ultrasound disintegration, extraction or chemolysis was done on 34 patients. A total of 15 patients presented with an operatively established nephrostomy, while percutaneous nephrostomy and subsequent dilation of the nephrostomy channel were done in 19. The rate of complete stone clearance was 19 of 20 stones after percutaneous nephrostomy and 8 of 16 stones in the group with an operatively established nephrostomy. The primary goal, to remove obstructing pelvic stones, was achieved in all cases. There were no untoward side effects, such as back pressure damage owing to flushing of the collecting system during ultrasound disintegration, or persistent…
Leukocyte migration test (LMT) in patients with thyroid disease: the response to human thyroid subcellular fractions.
1981
The response of circulating leukocytes to thyroid subcellular fractions was investigated in 19 patients with Graves' disease, 15 patients with Hashimoto's thyroiditis, 7 patients with toxic adenoma, 19 patients with nontoxic goiter and in 10 healthy students as control subjects. For this purpose, the leukocyte migration test of Soborg and Bendixen was performed against human crude thyroid extract (CTE), cell plasma membranes, nuclei, ribosomes, mitochondria and microsomes. Our results show positive LMT against: 1) CTE in patients with Graves' disease (61 +/- 13, p less than 0.001) and Hashimoto's thyroiditis (65 +/- 11, p less than 0.001) compared to controls (90 +/- 11); 2) cell plasma mem…
Mossbauer spectroscopic studies on the molecular dynamics of organotin(IV) polymers
1981
Abstract Linear organotin(IV) polymers with tin appended to the polymer chain or inserted into the polymer backbone have been characterized by Mossbauer spectroscopy. The lattice dynamics of three representative examples of these classes, as well as of a cross-linked organotin(IV) polymer, have been investigated by temperature-dependent Mossbauer spectroscopy. It has been shown that parameters associated with polymers having low interchain interactions practically correspond to those of molecular, non-coupled, solids.