showing 36 of ~574560 from 574555 documents
Chemotactic response of human alveolar macrophages and blood monocytes elicited by exposure to sulfur dioxide.
1996
An experimental study was undertaken to investigate the in vitro effect of sulfur dioxide on the chemotactic activity of alveolar macrophages (AM) and blood monocytes (BM). The cells were placed on a polycarbonate membrane and exposed to SO2 0.5, 1.5 and 2.5 ppm for 15 min. Control experiments were performed with exposure of the cells to synthetic air with 5% CO2. After gas exposure the cells were incubated with the chemotactic active agent C5a in 5% carbon dioxide (CO2) at 37 degrees C for 60 min. The numbers of AM and BM passing actively through the membrane were quantified using light microscopy. Our results show a dose-dependent reduction in the migration rate of cells under SO2 exposur…
Central obesity and hypertension: the role of plasma endothelin. Am J Hypertens
1996
Hypertension and central obesity are two conditions closely linked, but the mechanisms responsible for obesity-associated hypertension are still unclear. In the last few years, several studies addressed the role of endothelin-1 (ET-1) in the development and maintenance of hypertension. This study was designed to evaluate plasma ET-1 in normotensive and hypertensive central obese subjects compared with a lean healthy group. Our final goal was to analyze the relationship between plasma ET-1, blood pressure, and left ventricular structure and function in central obese subjects (both normotensives and hypertensives). ET-levels have been assessed by the radioimmunoassay method in 20 lean normote…
Calculation of miscibility behavior of multinary polymer blends
1996
A method for the calculation of phase diagrams (tie lines and binodal, spinodal, critical points and their stability) based exclusively on the Gibbs energy of mixing, δG, is presented which does not require the calculation of the derivatives with respect to the composition. The method is demonstrated for ternary mixtures of two homopolymers and the corresponding copolymer, and for quaternary and quinternary blends of five polymers exhibiting a closed miscibility gap. The advantages of the presented method become most obvious in the mathematical description of measured phase diagrams, where complex composition dependencies of the interaction parameter are observed.
Cytolytic T cell reactivity against melanoma-associated differentiation antigens in peripheral blood of melanoma patients and healthy individuals
1996
Antigenic peptides derived from several differentiation antigens of the melanocyte lineage were recently identified in human melanomas as targets for HLA-A2.1-restricted cytotoxic T lymphocytes (CTLs). To examine their potential role in tumour-directed immune responses in vivo, we determined CTL reactivity against seven antigenic peptides derived from the Melan A/MART-1, tyrosinase and gp100/Pmel17 antigens in the peripheral blood of 10 HLA-A2+ healthy controls and 26 HLA-A2+ melanoma patients. The influenza matrix peptide (GILGFVFTL) presented by HLA-A2.1 was used as a control peptide. CTL reactivity was assessed in a mixed lymphocyte 'peptide' culture assay. Reactivity against Melan A/MAR…
Some Finite Size Effects in Simulations of Glass Dynamics
1996
We present the results of a molecular dynamics computer simulation in which we investigate the dynamics of silica. By considering different system sizes, we show that in simulations of the dynamics of this strong glass former surprisingly large finite size effects are present. In particular we demonstrate that the relaxation times of the incoherent intermediate scattering function and the time dependence of the mean squared displacement are affected by such finite size effects. By compressing the system to high densities, we transform it to a fragile glass former and find that for that system these types of finite size effects are much weaker.
Fiber Bragg gratings with various chirp profiles made in etched tapers
1996
We have studied, both theoretically and experimentally, fibre Bragg gratings with a number of different chirp profiles. These chirp profiles can be easily achieved with a recently demonstrated technique involving a taper of desired profile being etched into the cladding of a fibre. Performances of gratings with linear, quadratic, periodically modulated and step chirp profiles are numerically analysed. The versatility of the technique is demonstrated when linearly and quadratically chirped gratings were made as examples of continuous chirp and gratings with step chirps were made as examples of discontinuously chirped structure.
3-D Shielding Analyses of the Vertical and Mid-Plane Ports in ITER
1996
A three dimensional (3-D) shielding analysis of the International Thermonuclear Experimental Reactor (ITER) has been performed with the aim of calculating the nuclear heating on the magnet system, correlating it to the existing vertical and horizontal ports. When these openings are left unshielded, more than 50 kW are calculated for the upper half of Toroidal Field Coil system and two of the Poloidal Field Coils. A simple plug, with same thickness as of the vacuum vessel can lower the heating to meet the imposed requirements. 5 refs., 6 figs., 4 tabs.
Evaluation of post-myocardial infarction regional and global left ventricular function by monoplane ventriculography: superiority of right versus lef…
1996
OBJECTIVES To study the significance of serial quantitative regional wall motion analysis, volumes, and ejection fraction findings as well as their prognostic implications derived from cineventriculography in 30 degrees right anterior oblique (RAO) projection in comparison with 60 degrees left anterior oblique (LAO) projection in post-myocardial infarction patients. Ventriculographic left ventricular parameters are accepted surrogates of mortality in myocardial infarction. Nowadays, in contrast to a biplanar approach in most institutions and clinical trials, the investigation is reduced to monoplanar ventriculography. However, it is not known whether the relevance of the two established pro…
Test of special relativity in an ion storage ring
1996
An accurate measurement of the Doppler effect in collinear laser spectroscopy has been performed at the TSR storage ring with electron cooled7Li+ ions atΒ=0.064. This experiment is a sensitive test of theγ=(1−Β2)−1/2 factor(Β=v/c) in the special theory of relativity. The Doppler shifted frequencies of the moving7Li+ ions are compared with calibrated molecular lines at rest. The frequencies at rest for the7Li+ ions are known from independent measurements. The Doppler shifted frequencies in the collinear experiment have been measured with a precision ofδv/v=6×10−9, mainly limited by the signal width of the resonance. A corresponding upper limit of 8×10−7 is deduced for any deviation of the ti…
Applications of level shift corrected perturbation theory in electronic spectroscopy
1996
Abstract Multiconfigurational second-order perturbation theory (CASPT2) with a level shift technique used to reduce the effect of intruder states has been tested for applications in electronic spectroscopy. The following molecules have been studied: formamide, adenine, stilbene, Ni(CO) 4 , and a model compound for the active site in the blue copper protein plastocyanin, Cu(Im) 2 (SH)(SH 2 ) + . The results show that the level shift technique can be used to remove the effects of the intruder states in all these molecules. In some cases a drift in the energies as a function of the level shift is observed, which however is small enough that the normal error bar for CASPT2 excitation energies (…
Isotope shift and hyperfine structure measurements at the242f Am fission isomer
1996
Istope shift and hyperfine structure measurements have been performed for the242fAm fission isomer with target production rates of only a few per second. The method is based on resonance ionization spectroscopy (RIS) in a buffer gas cell with radioactive decay detection of the ionization process (RADRIS). A relative isotope shift ratioX exp=IS242f,241/ IS243,241=41.7±0.9 has been measured for the 500.02 nm transition corresponding to a nuclear parameter Λ242f,241=5.4±0.3 fm2. The analysis of the quadrupole moment based on the deformed Fermi-model of the nuclear charge distribution including second order corrections results inQ 20=38.2 ±1.4( −0.8 +0.4 )model eb. The measurement of the hyperf…
Comment on ‘‘Multinucleon mechanisms in (γ,N) and (γ,NN) reactions’’
1996
Recently, calculations of (\ensuremath{\gamma},NN) cross sections in the \ensuremath{\Delta}(1232) region have been reported by J. Ryckebusch et al. [Phys. Rev. C 49, 2704 (1994)]. However, these calculations use an unjustified ansatz for the \ensuremath{\Delta} propagation, which leads to an underestimation of the (\ensuremath{\gamma},NN) cross section in the resonance region for quasifree kinematics. \textcopyright{} 1996 The American Physical Society.
Muscle activity in upper and lower rectus abdominus during abdominal exercises.
1996
Abstract Objective: To compare the intensity of the upper versus lower rectus abdominis (RA) muscle activity provoked by each of two different abdominal exercises and to contrast the intensity of contraction elicited by two different abdominal exercises on each RA muscle portion. Design: Nonrandomized control trial. Setting: Kinesiology laboratory in a university medicine faculty. Participants: Convenience sample of 33 healthy volunteers. Subjects who had practiced endurance or strength training activities (1.5 hours 3 days a week for 3 years) and those who had not accomplished that criterion comprised a high and a low physical activity group, respectively. Each of these two groups was divi…
New approach for numerical solution of configuration-space Faddeev equations
1996
A new computational scheme for solving the bound state configuration-space Faddeev equations is applied. The scheme is based on the spline-approximation and the adiabatic limit of Faddeev equations. An ordering of variables being in agreement with the limit was chosen. As a result the matrix of the eigenvalue problem has a sparse block structure. Calculations of the bound states of µpp, µdd, µtt mesic molecules and ¯pdd, ¯ptt antiprotonic ones, were performed. To check the method, calculations of the binding energies for such systems as the positronium ion Ps−,3H and3He were carried out. The results are compared with the best results of other authors.
L'alta noblesa catalana en la conquesta de València
1996
The studies about the conquest of Valence by the king Jaume I during the Xlllth century had emphasized the more great participation of the Aragonese nobility rather than the Catalan, so in the war as in the repartition of the land and the seigniories. Also it's affirmed that the Aragonese people remained in the Vanencian country, though the Catalans only came by religious reasons and went back to their land. This paper revises all the royal documents of the chancellery, the donations of the Repartiment and also the chronique of the king Jaume I, and demonstrates the opposed situation. The participation of the catalans nobility in the conquest of Valencia was very important —more than 150 kn…
Sobre las poblaciones de" Helianthemum asperum Lag." (Cistaceae) de la Sierra de Espadán, Castellón
1996
Se describe un nuevo taxon, Helianthemum asperum subsp. willkommii G. Mateo, M.B. Crespo & Aguilella, de las sierras litorales del sur de Castellón y norte de Valencia; sobre el que se aportan datos ecológicos, bioclimáticos, históricos, etc. complementarios.
Ion traps and their application in spectroscopy
1996
The general behaviour of Paul- and Penning ion traps is briefly described and some emphasis is given to the storage of highly charged ions. In the second part recent examples of laser and microwave spectroscopy on stored ions are given which illustrate the high precision and high sensitivity of these devices. We point out the possible application to laser spectroscopy on highly charged ions.
A frame shift mutation in a hot spot region of the nuclear autoantigen La (SS-B).
1996
A hot spot region was identified in the exon 7 of the nuclear autoantigen La (SS-B). Two La cDNAs were identified which contained a frame shift mutation in the hot spot region. One La cDNA was isolated from a cDNA library made from peripheral blood lymphocytes of an autoimmune patient with primary Sjogren's Syndrome, the other La cDNA was isolated from a human liver cDNA library. The patient's La cDNA had a deletion and the liver La cDNA had an insert of an (A)-residue at the same position. Inserts of 4, 16 and 24 more or less homogeneous (A)-residues were found at the same site in the three La retropseudogenes. The hot spot region located in one of the major autoepitope regions of the La a…
Measurement of the gj factor of hydrogenic ions: a sensitive test of bound state QED
1996
Thegj factor measurement of hydrogenic ions in the 1s ground state is with an expected accuracy of 10−7 a sensitive test of bound state QED. We expect to determine the deviations from the free electron value, caused by relativistic and radiative corrections, up to the orderα/4π(Zα)2 with an accuracy of 1%. As a first step, light ions like C5+ will be investigated. Later on, heavier hydrogenic ions up to U91+ will be examined using the accelerator facilities at GSI in Darmstadt.
Limited Proteolysis of Human α2-HS Glycoprotein/Fetuin
1996
alpha2-HS glycoprotein is a major protein of human plasma whose function is still obscure. A proteolytically processed form of alpha2-HS glycoprotein lacking a segment of 40 amino acid residues bridging its heavy and light chain portions ("connecting peptide") has been described suggesting that this peptide is released by post-translational processing to fulfill biological role(s) of alpha2-HS glycoprotein. To test this hypothesis we investigated how the connecting peptide is released from the parental molecule by limited proteolysis. We developed monoclonal antibodies to various portions of the connecting peptide and its NH2-terminal flanking region which cross-react with the native alpha2…
Laparoscopic-ultrasonographic combined technique for the creation of a neovagina in Mayer-Rokitansky-Kuster-Hauser syndrome
1996
Objective To create a neovagina using a combined laparoscopic and ultrasonographic technique in Mayer-Rokitansky-Kuster-Hauser syndrome by modification of Vecchietti's operation. Design Case report. Setting Division of Physiopathology of Reproduction, University of Palermo, Palermo, Italy. Main Outcome Measure(s) The advancement of the needle from the pseudohymen, through the vesicorectal space using a triple contrast ultrasonographic technique. Result(s) The ultrasonographic scanning guides the accurate transit from external genitalia to the peritoneal cavity. Conclusion(s) This original approach allowed a safe and rapid creation of a neovagina in a case of Mayer-Rokitansky-Kuster-Hauser s…
Mineralogy and geochemistry of Terra Rossa soils, western Sicily: insights into heavy metal fractionation and mobility
1996
Abstract The distribution of heavy metals in typical Terra Rossa soils and their partitioning in specific soil phases are estimated on the basis of the comparative evaluation of bulk contents, results from sequential chemical extraction procedure (SEP) and scanning electron microscopy/energy dispersive X-ray analysis ( SEM EDX ). A general natural enrichment of heavy metals with respect to average soil is observed. Cadmium proves to be remarkably high (up to 2.4 ppm). Large amounts of Fe, Cr, Cu, Ni, Pb, and Zn occur in the ‘residual’ fraction. The results indicate selective accumulation of the heavy metals in Fe oxides, present as hematite, goethite and maghemite. There is good evidence th…
Direct involvement of acid centers of polyaniline in charge transfer on organic acceptor
1996
Abstract Electrochemical behavior of hydroquinone and 4F-hydroquinone has been studied on Pt/polyaniline (PANI) electrodes in 1 M H 2 SO 4 solution. Redox transformation of quinone/hydroquinone systems takes place on PANI practically without overpotential and, probably, the two-electron charge transfer processes are realized in such systems. Reaction currents depend on PANI quantities deposited on the Pt electrode and the molecular complex is formed. There exists a great electronic exchange between acid centers of PANI and quinone/hydroquinone molecules, resulting in electronic conjugation of this surface state (adsorbed molecule) with the polymer. Existence of such complexes was confirmed …
The $q$-calculus for generic $q$ and $q$ a root of unity
1996
The $q$-calculus for generic $q$ is developed and related to the deformed oscillator of parameter $q^{1/2}$. By passing with care to the limit in which $q$ is a root of unity, one uncovers the full algebraic structure of ${{\cal Z}}_n$-graded fractional supersymmetry and its natural representation.
Guises and their Existence
1996
According to H-N. Castafieda, a guise the very thin individual which lies at the bottom of the ontological furniture of the world is indifferent to existence in a Meinongian way, in the sense that it remains the same whether it exists or not. Moreover, its existence does not alter its intentional character, as it is the very same individual which is thought of regardless of its being real or not. ~ In what follows, I will attempt to show that with regards to guises both theses are illegitimate, unless one introduces the notion of an existentiallyconditioned property as a counterfactual property which a guise has prior to its actual existence. To do so means to work out an amendment to Casta…
Central polynomials and matrix invariants
1996
LetK be a field, charK=0 andM n (K) the algebra ofn×n matrices overK. If λ=(λ1,…,λ m ) andμ=(μ 1,…,μ m ) are partitions ofn 2 let $$\begin{gathered} F^{\lambda ,\mu } = \sum\limits_{\sigma ,\tau \in S_n 2} {\left( {\operatorname{sgn} \sigma \tau } \right)x_\sigma (1) \cdot \cdot \cdot x_\sigma (\lambda _1 )^{y_\tau } (1)^{ \cdot \cdot \cdot } y_\tau (\mu _1 )^{x\sigma } (\lambda _1 + 1)} \hfill \\ \cdot \cdot \cdot x_\sigma (\lambda _1 + \lambda _2 )^{y_\tau } (\mu _1 ^{ + 1} )^{ \cdot \cdot \cdot y_\tau } (\mu _1 + \mu _2 ) \hfill \\ \cdot \cdot \cdot x_\sigma (\lambda _1 + \cdot \cdot \cdot + \lambda _{\mu - 1} ^{ + 1} ) \hfill \\ \cdot \cdot \cdot x_\sigma (n^2 )^{y_\tau } (\mu _1 ^{ + \…
Coherent, semicoherent and incoherent pion production in heavy-ion reactions
1996
Abstract Two types of coherent pion production in heavy-ion collisions are studied and calculations are performed for 12C against 12C collisions. The first one, doubly coherent production, produces a pion in one nucleus leaving it in its ground state, while the second nucleus is excited to the 1+, T = 1 state. The second process, semicoherent production, also leaves in its ground state the nucleus where the pion is produced while the second one is broken. The cross sections for forward pions are compared to the standard incoherent production process. We observe that at energies below 130 MeV/A the semicoherent process dominates the cross section for forward pion angles while at large energi…
Nitrogen-15 NMR Studies on Hydrazines. 2— Substituent Effect Analysis inortho-Substituted Phenylhydrazines and Anilines
1996
15N and 13C NMR spectra of some ortho-substituted phenylhydrazines were measured at natural isotope abundance in DMSO-d6 solutions. The substituent present exerts a larger effect on the chemical shift of the nitrogen atom directly bound to the aromatic ring (N-1), the second one (N-2) showing an attenuated trend of similar sign. Contrary to what observed for para and meta isomers, the cross-correlation between N-1 and N-2 SCS values of ortho-substituted phenylhydrazines is not satisfactory; on the other hand, N-1 SCSs show a reasonably good linear regression with the σR− constants. As expected, no correlation was found between N-1 and C-1 or H-1 SCS values. Correlations between 13C and 15N …
Increased responsiveness of human pulmonary arteries in patients with positive bronchodilator response.
1996
Abstract 1. The effects of noradrenaline, endothelin-1, acetylcholine and sodium nitroprusside were studied in isolated pulmonary arteries obtained from 14 patients undergoing lobectomy for lung carcinoma. Seven patients had shown increased response to a bronchodilator test prior to operation. In the remaining patients (control) the bronchodilator test was negative. 2. Artery rings from patients with a positive bronchodilator response showed greater contraction to noradrenaline (pD2 = 6.44 +/- 0.1; Emax = 93 +/- 9% of response to 100 mM KCl) and endothelin-1 (pD2 = 8.92 +/- 0.1; Emax = 130 +/- 16%) than the rings from control patients (pD2 = 6.04 +/- 0.08; Emax = 56 +/- 8% for noradrenaline…
Invariant circles in the Bogdanov-Takens bifurcation for diffeomorphisms
1996
AbstractWe study a generic, real analytic unfolding of a planar diffeomorphism having a fixed point with unipotent linear part. In the analogue for vector fields an open parameter domain is known to exist, with a unique limit cycle. This domain is bounded by curves corresponding to a Hopf bifurcation and to a homoclinic connection. In the present case of analytic diffeomorphisms, a similar domain is shown to exist, with a normally hyperbolic invariant circle. It follows that all the ‘interesting’ dynamics, concerning the destruction of the invariant circle and the transition to trivial dynamics by the creation and death of homoclinic points, takes place in an exponentially small part of the…
Has pharmaceutical research become more scientific?
1996
Pharmaceutical research continues to be highly empirical, despite some recent writings arguing that it has become more scientific. Contrary to a study asserting that Mevacor, Tagamet, and Capoten demonstrate the success of targeted research, these drugs were discovered only after many years of following leads. Two hypotheses implied by the proposition that pharmaceutical research has become more scientific are tested. The first hypothesis is that the uncertainty of research has fallen. The second is that the number of publications by scientists in the industry has increased. Both are rejected.
Photoelectron spectrum of poly(methyl-n-propylsilane): a valence band theoretical interpretation
1996
Abstract The results of a theoretical investigation of the photoelectron spectrum of poly(methyl-n-propylsilane) are reported. The simulation of the UPS spectrum has been obtained from band structure calculations performed using the valence effective Hamiltonian method (VEH). The theoretical spectrum is fully consistent with the experimental UPS spectrum, and an excellent quantitative agreement is observed when the energies of the main peaks of both spectra are compared. A complete analysis of the contributions to the main peaks, together with a detailed interpretation of all the photoemission bands observed in the experimental spectrum have also been performed.
Inducible NO synthase II and neuronal NO synthase I are constitutively expressed in different structures of guinea pig skeletal muscle: implications …
1996
The expression of NOS isoforms was studied in guinea pig skeletal muscle at the mRNA and protein level, and the effect of NO on contractile response was examined. Ribonuclease protection analyses demonstrated NOS I and NOS II mRNAs in diaphragm and gastrocnemius muscle. In Western blots, NOS I and NOS II immunoreactivities were found in the particulate but not the soluble fraction of skeletal muscle. NOS activity was found almost exclusively in the particulate fraction. About 50% of this activity was Ca2+ independent. In immunohistochemistry, the anti-NOS I antibody stained distinct membrane regions of muscle fibers. The most intense staining was seen in neuromuscular endplates identified b…
Involution codimensions and trace codimensions of matrices are asymptotically equal
1996
We calculate the asymptotic growth oft n (M p (F),*) andc n (M p (F),*), the trace and ordinary *-codimensions ofp×p matrices with involution. To do this we first calculate the asymptotic growth oft n and then show thatc n ⋍t n .
Mesozoic and Paleogene megabreccias in Southern Sicily: New data on the Triassic Paleomargin of the Siculo-Tunisian platform
1996
Mesozoic and Paleogene clastic carbonates in deep-water successions outcropping in the Sicani mountains (central southern Sicily) represent debris-flow and turbidite deposits accumulated in slope/base-of-slope sectors of the Sicanian Basin, a Permian to Miocene deep-water sedimentary domain of Sicily. Reef-derived carbonates of late Triassic age are frequently found among the clastic elements of these deposits, in association with other shallow and deep-water Mesozoic carbonates. The provide us with new data on the stratigraphic setting of a platform paleomargin now buried beneath the Sicilian thrust and fold belt. This paleomargin bounded the wide middle and upper Triassic carbonate platfo…