showing 36 of ~574560 from 574555 documents
Feinstruktur eines maxillaren Muskelrezeptors bei Oncopeltus fasciatus (Insecta, Heteroptera)
1987
Im Kopf von Oncopeltus fasciatus wird erstmals fur Insekten ein maxillarer nicht-ciliarer Muskelrezeptor in seiner Feinstruktur beschrieben. Er ist zwischen dem Hypopharynx-Flugel und dem Maxillen-Hebel aufgespannt und wird dementsprechend bei der Protraktion der Maxille gedehnt. Der reizubermittelnde Teil ist zusammengesetzt aus zwei caudal gelegenen, sehr dunnen Muskelfasern und einem Bindegewebs-Strang im vorderen Drittel. Die beiden Fasern des Rezeptor-Muskels bilden in ihrem vorderen Bereich eine Rohre. Die motorische Innervierung der Fasern geschieht vom Lumen der Rohre her. Funf Sinneszellen senden ihre Dendriten zum Bindegewebs-Strang, wo sie zwischen den Fibrillen enden. Der beschr…
Naloxone increases the response of growth hormone and prolactin to stimuli in obese humans.
1987
Opiates stimulate the growth hormone and prolactin responses to stimuli in non-obese humans. Obese patients, however, show lowered growth hormone and prolactin responses and raised beta-endorphin levels. We therefore investigated the effect of the opiate antagonist naloxone on the stimulated growth hormone and prolactin secretions in a controlled double-blind study in obese patients. All patients received 200 micrograms TRH and 0.5 g/kg b.w. arginine together with 2 mg of naloxone or placebo i.v. in a randomized sequence. The TRH- and arginine-induced increases in prolactin and growth hormone were significantly greater after administration of naloxone (p less than 0.05). Naloxone also produ…
Spontaneous fragmentation of multiply charged metal clusters.
1987
Alternative pathway activation of T cells by binding of CD2 to its cell-surface ligand.
1987
Activation of resting T lymphocytes is initiated by the interaction of cell-surface receptors with their corresponding ligands. In addition to activation through the CD3 (T3)-Ti antigen-receptor complex1, recent experiments have demonstrated induction of T-cell proliferation through the CD2 (T11) molecule2–4, traditionally known as the erythrocyte(E)-receptor, through which T cells can bind red blood cells (RBC)5–7. This 'alternative pathway' of T-cell activation2 was observed in vitro in response to combinations of anti-CD2 monoclonal antibodies (mAbs) that bind to distinct epitopes of CD2, such as mAbs against T112 plus T113 (ref. 2). The physiological importance of this activation pathwa…
Jyväskylän Ikääntyvien yliopisto
1987
Production of stable cytolytic T-cell clones directed against autologous human melanoma
1987
We have attempted to optimize the production of stable human cytolytic T lymphocyte clones directed against autologous melanoma cell lines. MLTC were restimulated every week with irradiated melanoma cells in medium containing human serum and IL-2. After 21 to 35 days, in 5 out of 6 patients, these cultures expressed a preferential cytolytic activity against the autologous melanoma cells, as compared to autologous EBV-B cells or NK target K562. Limiting dilution of MLTC responder cells was performed at times varying from days 7 to 28, in medium containing IL-2 and allogeneic EBV-B cells as feeders. Approximately 1% of these responder cells gave rise to CTL clones that lysed the autologous me…
ChemInform Abstract: Spectroscopic and Theoretical Studies on the Internal Rotational Barrier of 1-Acetylcyclohexene
1987
Abstract MINDO-3 molecular orbital calculations with full geometry optimization have been carried out on 1-acetylcyclohexene (ACH) in order to estimate the rotational barrier for the acetyl group, and to localize the less energetic conformation. MNDO calculations have also been carried out for comparative purposes. Both methods point to the non-delocalized structure with the two π-clouds perpendicular to the less energetic conformation. A decomposition of the barrier energy by means of Fourier analysis is made in order to characterize the contributions to the barrier. The UV spectrum of ACH has been recorded both in vapor phase and in hexane solution. These spectra are related to the one ca…
ChemInform Abstract: Evidence for the Formation of 1,3- and 1,4-Dehydrobenzenes in the Thermal Decomposition of Diaryliodonium-carboxylates.
1987
Abstract Abstract: Generation of m- and p-benzynes in decomposition of diaryliodonium- 3- and 4-carboxylates is demonstrated by three-phase method.
A stepper motor-driven microelectrode positioner
1987
The mechanical elements and the electronic control system from a stepper motor-driven microelectrode positioner is described. The unit embodies a high-precision small step angle hybrid motor. The compact, rugged and totally concentric design of the mechanic, by a spindle mechanism achieves the necessary precision by translating the stepwise rotations of the motor into steps of linear movement. The system takes advantage of commercially available low friction parts such as ball bearings, ball bushings and axles with hardened surfaces. The related electronic control unit is designed around the most recent integrated circuitry which is both sophisticated and economical. Though the described sy…
Analysis of F-wave in metabolic neuropathies: a comparative study in uremic and diabetic patients.
1987
Motor nerve conduction study along the entire length of the ulnar and tibialis posterior nerves was carried out in 30 diabetics compared with 30 uremic patients and 30 control subjects. The conduction in the proximal and the distal nerve segments was evaluated by the determination of the M and F latencies, MNCV (between the stimulus sites), FWCV (between the spinal cord and the stimulus sites), and F-ratio (conduction time ratio of proximal to distal segment). In both groups of patients the lower limbs appear much more involved than the upper, where the ulnar nerve is more commonly affected in uremic than in diabetic patients. In diabetic neuropathy the motor conduction abnormalities are di…
Ultrasonic mensuration of fetal limb bones in the second and third trimesters
1987
Growth of fetal limb bones has been examined in a prospective cross-sectional study in 530 patients between 13 and 42 weeks of gestation by ultrasound. The length of the femur, tibia, humerus, and radius were measured in all cases, and fibula and ulna in 393 cases. For each week of gestation mean lengths (+/- 2 standard deviations) were calculated. All limb bones showed linear growth from 13 weeks to 25 weeks of gestation, after which the growth curve appeared nonlinear. A strong linear relationship (r greater than 0.98) between the BPD and bone length was found for each bone. In five aborted fetuses, prenatal sonographic measurements of the ossified diaphyses were compared with the postnat…
Temperature and pressure dependence of the viscosities of perfluoropolyether fluids
1987
The viscosities of two structurally different perfluoropolyether fluids were determined at a series of temperatures and pressures, from 25 to 100°C and from 1 to 1000 bars. Flow activation energies and volumes as well as their temperature and pressure coefficients were derived. An attempt was made to relate measured and derived quantities to the compound structures.
Psychische Determinanten der Mitarbeit kieferorthopädischer Patienten — ein Beitrag zur Frage der Kooperationsprognose
1987
In einer umfangreichen Untersuchung wurden Patienten, die nach Einschatzung ihrer Behandler in der kieferorthopadischen Behandlung besonders gut mitarbeiteten, solchen gegenubergestellt, die besonders schlecht mitarbeiteten. Dabei wurde ein psychodiagnostisches Instrumentarium verwendet, dessen Einzelverfahren so ausgewahlt waren, das sie sich fur Kinder und Jugendliche eigneten und das der erfaste Inhalt etwas mit Kooperationsbereitschaft, Pflichteifer, Gewissenhaftigkeit und Ausdauer zu tun haben konnte. Es ergaben sich mehrere signifikante Unterschiede. Aufgrund der vorliegenden Ergebnisse kann der Typ des nichtkooperativen Patienten beschrieben werden.
Nuclear shape transition in neutron-deficient gold isotopes
1987
4 pages, 1 table, 4 figures.
On global solutions of the Maxwell-Dirac equations
1987
We prove, for the Maxwell-Dirac equations in 1+3 dimensions, that modified wave operators exist on a domain of small entire test functions of exponential type and that the Cauchy problem, inR+×R3, has a unique solution for each initial condition (att=0) which is in the image of the wave operator. The modification of the wave operator, which eliminates infrared divergences, is given by approximate solutions of the Hamilton-Jacobi equation, for a relativistic electron in an electromagnetic potential. The modified wave operator linearizes the Maxwell-Dirac equations to their linear part.
ETIOPATOGENESI DELL'ATRESIA INTESTINALE. Ricerche Sperimentali condotte sull'Embrione di pollo
1987
Gli Autoyi hanno eseguito una serie di ricerche sperimentali su embrioni di Gallus Domesticus allo scopo di verificare alcune cause di atresia inyestinale
Reactions of pyridine-2-carbaldimines with chloro-bridged palladium(II) and platinum(II) 2-methylallyl dimers. Solution behaviour of the cationic com…
1987
Abstract The reactions of pyridine-2-carbaldimines, py-2- CHNR (R = C6H4OMe-p, Me), with allylic dimers [MCl(n3-2-MeC3H4)]2 give rise to stoichiometry, concentration, solvent and temperature dependent equilibria, in which the cationic complexes [M(n3- 2-MeC3H4)(py-2-CHNR)]+ and the anion [MCl2(n3- 2-MeC3H4)]- or Cl- are involved. In general, the ligand/dimer reaction (1/1 molar ratio) yields the ionic products [M(n3-2-MeC3H4)(py-2-CHNR)]- [MCl2(n3-2-MeC3H4)], which can be isolated as solids, whereas the same reaction in a 1/0.5 molar ratio yields the species [M(n3-2-MeC3H4 )(py-2-CH NR)] Cl, which can be studied only in solution, but are easily converted into [M(n3-2-MeC3H4)(py-2-CH NR…
Sedaghatian congenital lethal metaphyseal chondrodysplasia—observations in a second Iranian family and histopathological studies
1987
In 1980, Sedaghatian described in two brothers and one sister a neonatally lethal disorder associated with slight rhizomelic limb shortness, mild platyspondyly, and severe metaphyseal dysplasia. Here data are presented on another Iranian infant with the Sedaghatian syndrome who died on day 4 and was found to have histologic evidence of severe epimetaphyseal dysplasia. The occurrence in children of both sexes in one instance, born to normal parents who were first cousins, and currently apparent confinement of the disorder to Iranians suggests that the Sedaghatian syndrome is an autosomal recessive trait with high gene frequency in Iranians. This may be a more complexly pleiotropic syndrome t…
Tunneling and point contact investigations of La1.85Sr0.15CuO4
1987
The high-T c superconductor La1.85Sr0.15CuO4 was investigated by means of point contact and tunneling measurements on small-sized contacts. We find different values for the energy gap at different points of the samples. The ratio 2Delta/k B T c ranges from about 3 to 6. For some point contacts we observe a clear signature of a supercurrent. Data for the temperature dependence of the critical current are presented.
The Case for a Local Net Value-Added Tax for Municipalities
1987
In this paper the case made by the Advisory Council of the Federal Ministry of Finance for reform of the local business tax in Germany is outlined. The criteria for a good local tax are described, and the proposals deriving from the Council are presented. The proposed reform is to introduce a local value-added tax of the income type. This tax would be defined on the base of business payroll, profits, interest paid, and rent. It would include businesses, professions, and administrative bodies. The reform is outlined and possible criticisms are assessed. With appropriate definitions of tax base and an enlargement of the group of taxpayers, the value-added tax is argued to be the best approac…
Immobilized glycolipids from human diploid fibroblasts inhibit DNA synthesis of cultured human fibroblasts*1
1987
Several previous studies have shown that glycolipids isolated from plasma membranes of cultured cells and added to cells in culture inhibit the growth rate in a concentration-dependent fashion. In order to investigate the possible involvement of glycolipids in the growth regulation of normal cells by cell-cell contacts, we tested the effect of immobilized glycolipids, isolated from human fibroblasts, on the DNA synthesis of freshly seeded fibroblasts. Gangliosides inhibited DNA synthesis to a great extent, whereas neutral glycolipids had only a minor effect. The degree of inhibition of DNA synthesis by immobilized gangliosides depended both on the cell density of the cultures from which the…
Functionalization with silyl enol ethers, VI Zinc chloride mediated alkoxyalkylation of O-methyl-O-trimethylsilyl) keten acetals with 2-alkoxy-1,3-di…
1987
O-Methyl-O-(trimethylsilyl) keten acetals2 were regioselectively alkoxyalkylated by 2-alkoxy-1,3-dioxolanes1 in the presence of zinc chloride. This method represents a good way for synthesis of α-protected β-keto carbonic esters4.
The decay scheme of the 3-s Isomer of100Nb and the properties of levels in100Mo
1987
Theβ− decay of the longer-lived isomer in100Nb has been studied at the fission-product separator JOSEF. Measurements ofγ-ray singles spectra, ofγ-γ coincidences and ofγ-γ angular correlations have been performed. A value oft1/2=2.99(11)s has been determined for the isomer which probably hasIπ=4+ or 5+. A scheme of the levels of100Mo which are populated in the decay of this isomer has been established. Information on the spins of several states of100Mo has been obtained. Thus,I=0 levels have been identified at 1,505, 2,038 and 2,087 keV. The mixing ratios have been determined for the 22+→21+ and 23+→21+ transitions. The results provide evidence for a vibrational structure of100Mo with separa…
Characterization of an epithelial, nearly diploid liver cell strain, from Chinese hamster, able to activate promutagens
1987
Epithelial liver cells of the Chinese hamster (CHEL cells) were propagated in culture for 35 passages. At favourable cell densities, the population doubling time in normal medium, was 20 h. L-Tyrosine amino transferase activity was retained at a measurable level, but its enhancement by dexamethasone was detected solely in cells of early passages. Pyruvate kinase was strongly activated by fructose-1,6-biphosphate at low substrate concentrations. These enzymatic properties suggest that the CHEL cells are derived from a sub-population of parenchymal hepatocytes or from cells closely related to parenchymal hepatocytes. With a lag period of a few hours, CHEL cultures metabolized benzo[a]pyrene. …
�ber die Stabilit�t periodischer L�sungen bei zeitabh�ngigen Hamiltonschen Differentialgleichungen von einem Freiheitsgrad
1987
The preservation of certain stable period solutions of the harmonic oscillator under small time-dependent, non-isochronous, and Hamiltonian perturbations is proved.
Bile salt-stimulated lipase activity in human colostrum from mothers of infants of different gestational age and birthweight.
1987
. The bile salt-stimulated lipase (BSSL) activity was measured in milk collected at 3–4 days postpartum (colostrum) from 36 mothers divided into three groups according to gestational age and birthweight of their infants. BSSL activity changed with the length of gestation. Preterm colostrum presented a mean activity significantly higher than the term groups (small-for-gestational age and appropriate-for-gestational age) which had similar values. The ratio of BSSL activity to the estimated fat content was 6.33 in colostrum of mothers who delivered preterm and 4.20 in colostrum of both groups of term mothers. These data suggest that preterm colostrum has a higher fat digesting potential than t…
Effects of Cooking Method upon Flavor of Carrots and Peas
1987
Two modalities of pressure (atmospheric pressure and high-pressure of 5.5.104 Pa) and two modalities of immersion (boiling and cooking in steam) were combined factorially to produce four ways of cooking. These different cooking methods were studied on two vegetables: carrots and peas. Sensory attributes of samples were assessed on an unstructured scale. Steam-cooked vegetables have higher sensory attributes (odor and flavor intensities, typical odor and flavor notes, sweetness). Larger losses of soluble solids and volatiles are believed to account for these differences between vegetables cooked in water and cooked in steam.
Methylation of 2-phenylamino-1,3,4-thiadiazole. A structure debated
1987
The true identity of the 4-methyl-5-phenylimino-δ2-1,3,4-thiadiazoline (A) has been demonstrated. The reactions, previously reported in the literature to give A have been repeated and the structure of the compounds obtained has been established.
Photoreceptors and respiratory electron flow involvement in the activity of acifluorfen-methyl and LS 82-556 on nonchlorophyllous soybean cells
1987
Abstract The diphenyl ether acifluorfen-methyl [AFM; methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate] and the pyridine derivative LS 82-556 [( S )-3- N -(methylbenzyl)carbamoyl-5-propionyl-2,6-lutidine] induce light-dependent polyunsaturated fatty acid peroxidation, leading to general membrane disruption. Although devoid of functional chloroplasts, cultured soybean cells are sensitive to AFM and LS 82-556 only in the light. The possible involvement of carotenoids and respiratory electron flow was examined by monitoring ethane evolution, fluorescein release, and dry weight/fresh weight ratio alteration. Herbicide effects on cells exposed to white light or blue light (380–540 n…
Noradrenergic innervation of the pineal gland — histochemical basis of scintigraphic imaging?
1987
There is first evidence that the adult human pineal gland may be equipped with noradrenergic fibers as is the case in a variety of mammalian species. It therefore appears worthwhile to investigate the capacity of pineal noradrenergic nerves to take up 123I-MIBG, a prerequisite for scintigraphic imaging.
Interaction of sodium, lithium, caesium, and potassium ions with ascorbyl radicals.
1987
Abstract The influence of the concentration of sodium, lithium , caesium, and potassium ions as well as of the ionic strength of the solutions used on the dismutation rate of ascorbyl radicals has been investigated. While the dismutation rate was not influenced by Li+, it decreased, however, with increasing concentrations of the other ions investigated. The largest effect was obtained with Na+. This change in dismutation rate indicates a stabilizing effect on ascorbyl radical by these ions.
Microtubules and intermediate filaments of herpes simplex virus infected cells.
1987
The fate of microtubules and of vimentin or keratin containing intermediate filaments during infection with fusion or rounding producing strains of herpes simplex virus (HSV) was investigated. Microtubules polymerize early after fusion of cells. However, they do not reconstitute 6–7 hours post infection (p.i.) after release of a colcemid block. Keratin and vimentin are maintained around the original nucleus still inside of recruited cells in the polykaryocyte. Cells of fibroblastic and epithelial origin fuse. Inside of polykaryocytes keratin or vimentin containing fibers seem to polymerize. Keratin is to be found in invaginations in the nuclei surrounded by the inner layer of the nuclear me…
Electropherotype heterogeneity within serotypes of human rotavirus strains circulating in Italy
1987
Using solid-phase immune electron microscopy, 126 of 129 human rotavirus (HRV) strains could be serotyped directly in stools collected in Italy during the period 1981–1985. Prevalence was 70.5 per cent for serotype 1, and 13.2 per cent for each of serotypes 2 and 4. No serotype 3 strain was detected. In parallel, for 39 of 61 HRV strains tested the electropherotype of genomic RNA was successfully determined. Different electropherotypes were detected among strains of the same serotype, whereas the same electropherotype was found in HRV strains of different serotypes. Serotyping and electropherotyping of HRV strains appear to be complementary to each other, and both should be used in conjunct…
High-resolution positron lifetime spectrometer with BaF2 scintillators
1987
In this communication we report on a design of a fast coincidence positron lifetime spectrometer, which is based on single crystal barium fluoride (BaF2) scintillators. A good time resolution (190ps, FWHM), combined with a high efficiency, has been obtained in the normal experimental set-up (with cathode earthed in the photo multipliers). The pile-up effect is observed to disturbe the measured lifetimes in the 180 degree geometry due to the high detection efficiency of the BaF2 scintillator.
false
1987
X-ray measurements of stretched crosslinked liquid-crystalline side group polymers show that two types of orientation of the mesogenic groups relative to the polymer chains (parallel or perpendicular) are possible, depending on the structure of the polymer chain. For two liquid-crystalline polymethacrylates with long spacer groups (6 methylene units) the mesogenic groups orient preferably perpendicularly to the polymer chains (axis of strain). For three liquid-crystalline polyacrylates with long or short spacer groups (6 or 2 methylene units), the mesogenic groups orient preferably parallel to the polymer chains (axis of strain). The reason for this difference is not yet clear. These result…