bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the glucocorticoid receptor in early and late passage C‐6 glioma cells and in normal astrocytes derived from aged mouse cerebral hemispheres
Authors: Moutsatsou P. , Kazazoglou T. , Fleischer‐Lambropoulos H. , Psarra A.M.G. , Tsiapara A. , Sekeris C.E. , Stefanis C. , Vernadakis A. 
Published: July 2002

AbstractThe presence of the glucocorticoid receptor in early and late passage C‐6 glioma cells 2B clone and in astrocytes derived from aged mouse cerebral hemispheres has been documented by immunoblotting and/or immunofluorescence labelling. All cell types studied express the glucocorticoid receptor of molecular weight 97 KDa. In addition, in astrocytes derived from aged mouse cerebral hemispheres a smaller molecular weight polypeptide reacting with anti‐glucocorticoid receptor antibody was also demonstrated. No difference in the amount of the 97 KDa glucocorticoid receptor between early and late C‐6 2B cells was observed, whereas the astrocytes from aged cerebral hemispheres contained considerably reduced amounts of the glucocorticoid receptor compared to C‐6 2B cells. Late passage C‐6 2B cells were immunofluorescence labelled with the anti‐glucocorticoid antibody, the receptor being almost exclusively present in the cytoplasm, with particular concentration in the perinuclear region. The presence of glucocorticoid receptor of molecular weight 97 KDa in glial cells corroborates and expands the existing data based on radioligand binding and immunocytochemical studies. These cell populations can be exploited as a model system for the study of the effects of glucocorticoids on senescence and brain aging.
Evidence of psychological barriers in the conditional moments of major world stock indices
Authors: Cyree Ken B. , Domian Dale L. , Louton David A. , Yobaccio Elizabeth J. 
Published: July 2002

AbstractThis study investigates the existence of psychological barriers in the Dow Jones Industrial Average, the S&P 500, and six foreign stock indices. It is believed by many in the investment community that index levels that are multiples of 100 serve as barriers, and that markets may resist crossing these barriers. Although return dynamics in the neighborhood of barrier points are not identical for all series studied, we find aberrations in the conditional means and variances consistent with psychological barriers. In five of the eight indices studied, conditional mean returns are significantly higher after crossing a barrier as part of an upward move, while only two series exhibit significant mean effects after crossing a barrier as part of a downward move. In seven of the eight series studied, we find significant conditional variance effects coincident with a barrier crossing. In addition, most series exhibit evidence of autoregressive conditional heteroskedastic (ARCH), generalized ARCH (GARCH), and leverage effects.
The effect of physical training on skeletal muscle in patients with chronic heart failure
Authors: Kiilavuori K. , Näveri H. , Salmi T. , Härkönen M. 
Published: July 2002

AbstractBackground:The improvement of exercise capacity in patients with chronic heart failure (CHF) by physical training has been connected with reversal of the abnormalities in muscle fiber distribution and with the reduced activity of the enzymes of oxidative metabolism in skeletal muscle. However, the change in fiber type distribution induced by training is controversial and in previous studies the activities of the rate‐limiting enzymes of the metabolic pathways have not been measured.Aims:To examine the effect of dynamic training on percentage distribution of muscle fibers, on activities of the rate‐limiting enzymes of the metabolic pathways and on electrophysiology in skeletal muscle.Methods:A total of 27 patients with stable CHF (NYHA class II–III) were randomized to a training (N=12) or a control (N=15) group. The training group exercised on a bicycle ergometer for 30 min three times a week for 3 months using a load corresponding to 50–60% of their peak oxygen consumption. This was followed by a 3‐month training period at home according to personal instructions. The control group did not change its physical activities. We studied muscle histology and measured the activities of the rate‐limiting enzymes of anaerobic glycolysis (phosphofructokinase, PFK), glycogenolysis (phosphorylase), citric acid cycle (α‐ketoglurate dehydrogenase, KGDH) and fatty acid oxidation (carnitinepalmitoyl transferase I and II, CPT I and II) from biopsies of the vastus lateralis muscle at baseline and after 3 and 6 months. Muscle strength and strength endurance with surface EMG and macro EMG of the right knee extensors were also determined.Results:Exercise capacity, particularly submaximal, improved in the training group. The activity of PFK rose significantly but that of the other enzymes did not when compared with the change in the controls. Training had no effect on the percentage distribution of slow‐twitch and fast‐twitch muscle fibers or on capillary density around these fibers in skeletal muscle. Maximum voluntary force, strength endurance and the function of motor units remained unaffected.Conclusions:Dynamic training results in improved exercise endurance in CHF. In skeletal muscle, the capacity of anaerobic glycolysis is increased but that of the citric acid cycle and fatty acid oxidation is not. Furthermore, the improvement in exercise endurance seems to be independent of changes in the percentage distribution of muscle fibers, capillarity or electrophysiological factors.
Cardiovascular disease and outcome of acute stroke: influence of pre‐existing cardiac failure
Authors: Sharma Jagdish C. , Fletcher Sally , Vassallo Michael , Ross Ian 
Published: July 2002

AbstractBackground and aims:Whilst a number of variables, mostly a consequence of a stroke, are known to predict mortality of acute stroke there is limited information on the significance of pre‐existing cardiovascular variables on stroke mortality. We have investigated the influence of pre‐existing cardiovascular factors in one cohort of stroke patients.Methods:We studied 295 patients, mean age 74 ± 10 (range 34–96) years; 133 males, presenting with acute stroke for pre‐existing cardiovascular disease (CVD) defined as hypertension, atrial fibrillation (AF), ischaemic heart disease (IHD) and cardiac failure (CF). In addition, data were collected on epidemiological and neurological variables known to influence stroke mortality. The most significant of the cardiovascular factors was further investigated against all the other cardiovascular groups together and against those without any CVD. Outcome was measured as their influence on acute phase and 3‐month mortality.Results:There was no significant difference in 3‐month mortality with hypertension (P = 0.62) and IHD (P = 0.33) but there was a significant higher mortality in patients with AF (P = 0.05) and CF (P < 0.001). CF was more significant than all other CVD (hypertension+AF+IHD) together without the failure (P < 0.001); odds ratio of 4.5 (95% CI 2.28–9.07). Partial correlation coefficient revealed CF to be an independent significant variable to influence stroke mortality when controlled with AF, stroke syndromes, age, incontinence, pyrexia, dysphagia and Glasgow coma score.Conclusions:Pre‐existing CF has an adverse influence on stroke mortality independent of other known factors. Cardiovascular factors without failure do not have such an effect except the marginal effect of AF.
Serum N‐terminal atrial natriuretic peptide in adult patients late after surgical repair of atrial septal defect
Authors: Iivainen Tiina E. , Groundstroem Kaj W.E. , Lahtela Jorma T. , Talvensaari Taisto J. , Pasternack Amos , Uusitalo Arto 
Published: July 2002

AbstractBackground:The purpose of surgical closure of atrial septal defect (ASD) is to relieve the cardiovascular system from a haemodynamic burden. Excessive amounts of atrial peptides are released in congestive heart failure, valvular diseases and congenital heart diseases.Aims:To examine whether patients after surgical repair of ASD have higher concentrations of N‐terminal atrial natriuretic peptide (ANP‐N) than age‐, sex‐ and body mass index (BMI)‐matched control subjects.Methods:Medical history, physical examination, standard 12‐lead electrocardiogram, and ANP‐N concentrations were obtained in 65 adult patients operated for ASD at the age of 21 ± 13 years (mean ± standard deviation), 21 ± 6 years after surgical closure of ASD. Sixty‐seven healthy subjects matched for age, sex and BMI served as controls.Results:In the patients serum ANP‐N was higher than in the control subjects 0.41 ± 0.32 nmol/l, median 0.31 nmol/l, interquartile range (IQR) 0.21–0.49 nmol/l vs. 0.24 ± 0.12 nmol/l, median 0.23 nmol/l, IQR 0.17–0.29 nmol/l, (P = 0.0003). Patients with concomitant diseases had higher ANP‐N concentrations (0.51 ± 0.39 nmol/l, median 0.34, IQR 0.26–0.73 nmol/l) than ASD patients without any history or signs of disease (0.28 ± 0.16 nmol/l, median 0.27, IQR 0.17–0.40 nmol/l, P = 0.01). The ‘healthy’ ASD patients had higher hormone concentrations than age‐, sex‐ and BMI‐matched control subjects (0.28 ± 0.16 median 0.27 nmol/l, IQR 0.17–0.40 nmol/l and 0.21 ± 0.07 nmol/l, median 0.20 nmol/l, IQR 0.15–0.27 nmol/l, P = 0.01). Multiple stepwise linear regression analysis showed that age at operation was strongly associated with the post‐operative ANP‐N concentration (r2 = 0.25, P = 0.0002).Conclusion:ASD patients have higher ANP‐N concentrations late after surgical repair. Hormone levels correlate with age at operation. Our finding supports the clinical praxis of operating on these patients in their childhood and adolescence.
The experimental determination of the temperature dependence of the total emissivity of GaAs using a new temperature measurement technique
Authors: Timans P. J. 
Published: July 2002

Temperature measurement and control are key issues in many technologically important areas of semiconductor processing, including rapid thermal annealing, molecular-beam epitaxy, and plasma processing. As a result, the development of accurate techniques for the characterization of thermal cycles is a problem of great practical interest. In this study, the total emissivity of specimens of GaAs was determined using a technique which combines isothermal electron-beam heating with a temperature measurement method which exploits the temperature dependence of the band gap of GaAs. Emission spectra from the GaAs specimens were recorded for a range of heating power densities. These spectra display a maximum near the semiconductor absorption edge, because the blackbody radiation rises with increasing wavelength but the spectral emissivity decreases rapidly once the photon energy falls below the band gap. The temperature was determined by fitting the Planck radiation function to the high-energy side of the maximum. This allowed a self-consistent determination of the temperature dependence of the position of the absorption edge. The results were used to calibrate a second set of experiments in which a corresponding set of reflection spectra were recorded. The reflection spectra exhibit a large change in reflectivity at the absorption edge, because light starts being reflected from the back surface of the wafer as well as from the front when it becomes transparent.
The reflection spectra provide a convenient method of temperature measurement because the intensity of the reflected light can be much larger than that of the emitted light. The large signal levels should permit temperature measurements to be made with good spatial and temporal resolution, even for samples at low temperatures. The temperature measurements can be performed with a precision of about 2 °C, and in this study the accuracy was ±5 °C. As a result of these measurements the total hemispherical emissivity of the GaAs specimens was determined over the temperature range from 350 to 630 °C. The values for the total emissivity of GaAs reported in this paper are believed to be the first direct, experimental measurements of this quantity. It was found that the total hemispherical emissivity of 485-μm-thick specimens rises from 0.08 at 350 °C to 0.28 at 630 °C. The electron-beam heating method used in this work presents distinct advantages for this type of measurement because there is little background light in the apparatus, the energy coupling to the specimen is not affected by its optical properties, and the surroundings remain cool. The power input can be accurately determined from the electron-beam energy and current and the scan area, and hence the total emissivity can be determined in a straightforward manner.
Effect of ion angular distributions on microloading in oxygen reactive-ion etching of submicrometer polymer trenches
Authors: Janes Joachim , Pilz Wolfgang 
Published: July 2002

The etch rate of the resist by energetic reactive ions (O+, O+2) from a 13.56 MHz plasma was studied as a function of the aspect ratio. Using a trilevel sequence, submicrometer grooves with widths of 500, 200, 100, and 50 nm are etched with an oxygen rf plasma in a parallel-plate reactor. Pattern transfer into the polymer photoresist proceeds via a thin silicon nitride mask. With increasing aspect ratio a decrease in etch rate is observed for increasing etch time resulting in a diminished etch depth for small width grooves. This effect is commonly called microloading and its origin is subject to many discussions. With the assumption that lower local etch rates are caused by the characteristics of particle fluxes entering the structures it is necessary to consider the ion energy distributions and the ion angular distributions of O+ and O+2 emerging from the oxygen rf plasma bombarding the surface to be structured.
The measurement of ion angular impact energy distributions of O+ and O+2 is performed in an apparatus simulating a parallel-plate rf reactor. Through a small orifice in the rf-powered electrode ions are sampled and are analyzed in a quadrupole mass spectrometer equipped with an energy filter. Tilting the detection system with the vertex lying in the orifice, mass selected ion energy distributions are measured at each angle. O+2 energy distributions consist of the well-known peaked structures caused by charge-exchange collisions in the plasma sheath. The angular distributions are characterized by mace-shaped structures with an angular width of about 2° accompanied by wings with intensity maxima at about ±2° for most of the experimental conditions considered. O+ energy distributions consist of bimodal split high-energy peaks and continuous intensities between 50 eV and the maximal energy defined by the potential drop across the sheath. The angular distributions of the high-energy O+ ions have widths between 2° and 6° while the continuous part of the ion energy distributions exhibits angular widths between 7° and 11°.
The phenomena observed in the ion energy distributions and ion angular distributions are a result of scattering mechanisms of ions with O2 parent gas molecules in the plasma sheath. The experimental ion angular distributions are used to model the effect of lower local etch rates. Assuming that direct impingement of particles onto the bottom surface of a structure is the dominant ablation mechanism it is possible to correlate the effect of lower local etch rates with the angularly broadened flux of O+ ions.
C
i
s-glyoxal in effusive and supersonic beams. Spectroscopy, selective pumping, and c
i
s–t
r
a
n
s interconversion
Authors: Butz Kirk W. , Johnson Jeffrey R. , Krajnovich Douglas J. , Parmenter Charles S. 
Published: July 2002

S 1–S0 fluorescence excitation and dispersed fluorescence spectra from molecular beams containing both trans- and cis-glyoxal have been used to extend the characterization of the 1A1 (S0) and 1B1 (S1) states of cis-glyoxal. Explorations using both effusive and supersonic beams with rotational temperatures ranging from 350 to 30 K have revealed no conditions where cis can be pumped (S1←S0) without simultaneous excitation of trans. Selective cis excitation at low beam temperatures is hampered by highly efficient cis→trans conformational interconversion in the molecular beam expansions. Under conditions of optimal cis:trans contrast (cool expansions with Ar carrier gas), four new S1–S0 cis absorption bands (510,520,610, and 720 ) are identified, yielding cis frequencies ν′5 =303 cm−1, ν6 =713 cm−1, and 2ν′7 =688 cm−1. Single vibronic level fluorescence spectra have been obtained from the levels 00, 51, and 61 of cis-glyoxal, from which values of two cis S0 fundamentals are newly established: ν4 =826 cm−1 and ν′′6 =1049 cm−1. Previous assignments of ν4 and ν′′8 are shown to be incorrect and
ν8 now joins the list of unknown frequencies. The 1B1–1A1 system of cis-glyoxal contains forbidden transitions, vibronically induced by Δv=±1 changes in the a2 mode ν6. A remeasurement of the cis–trans energy separation in the ground electronic state gives ΔH=1350±200 cm−1, matching to within experimental uncertainty a previous experimental determination. As an aside, the trans-glyoxal fundamental ν′′3 =1352 cm−1 has been obtained from observations of the trans 301 and 301510 transitions. With this addition, all trans S0 fundamentals have now been directly measured.
Photoelectron spectroscopic studies of polyatomic molecules: Angular distributions for ionization in oriented T
d systems
Authors: Chandra N. 
Published: July 2002

A recently developed theory for angular distribution of electrons ejected by interaction of light with nonlinear molecules held fixed in space has been used to study ionization in a1 orbital of those systems which transform like the Td point symmetry group. Expressions for photoelectron angular distributions in the dipole approximation with the electric vector in the radiation beam both perpendicular and parallel to the molecular axis are derived. The properties of the two formulas, which are found to have completely different structures, have been studied. These expressions are shown to depend not only on all those quantities [i.e., the partial integrated cross-section σ̄, the asymmetry parameter β̄, and the polar angle θ of the propagation vector k (k,θ,φ) of the ejected electron] which are present in photoionization of an unoriented molecule, but involve in certain cases also the azimuthal angle φ, phase shifts of the continuum waves representing the outgoing electron, and the phase of the dipole transition amplitudes. Such fixed-molecule photoelectron angular distributions will therefore provide more stringent tests of theoretical models and probes of photoionization dynamics than the hitherto performed gas phase experiments on randomly oriented targets. They can also be used to identify the orientation of a molecule and/or geometry of a chemisorption site. The formulation presented here sets a frame work for the analysis of measurements and the calculations of spectra in those Td molecules which are fixed in space. We have applied it, as an example, to ionization in 4a1, 6a1, and 7a1 orbitals of oriented CF4, CCl4, and SiCl4, respectively. Without doing any dynamical calculations, using instead the experimentally measured values of σ̄ and β̄ as a function of the photon wavelength, the variations in the angular distributions with respect to the energy of the ejected electron as well as to the angles (θ,φ) and to the phases (which are treated as parameters) involved have been studied in detail. These distributions are found to have very rich and complicated structures arising from the spectral, angular, and/or phase variations of the angular momentum composition
of the photocurrent.
Theory of anharmonically modified Coriolis coupling in the S1 state of benzene and relation to experiment
Authors: Helman Adam , Marcus R. A. 
Published: July 2002

Avoided crossings between quasidegenerate rovibrational states in the Doppler-free two-photon excitation of the 141 mode in the S1 excited state of benzene are treated theoretically. Two sets of avoided crossings in plots of spectral line frequency vs J at a given K and ΔK have been reported experimentally between an initially prepared ‘‘light’’ state (141 in zeroth order) and dark states, namely, one which in zeroth order is a 51101161 state, the other being in zeroth order a 62111 and/or possibly a 31161 state, implicated earlier by Neusser et al. The identification of these states makes the phenomenon an excellent candidate for treatment of the avoided crossing via a Van Vleck transformation, no other basis set states being needed for the diagonalization in order to extract the important features. Two successive transformations are used for handling direct coupling and coupling via virtual states. The dominant calculated contribution to the coupling is, jointly, Coriolis plus cubic–cubic anharmonic interactions between vibrational modes.
Playing less of a role are Coriolis terms in which the inverse moment of inertia tensor is expanded up to quadratic terms in the coordinates. There results a 5×5 (for coupling to 51101161 ) and a 3×3 (for coupling to 62111 or 31161 ) matrix of the transformed Hamiltonian, each of which can also be described, if desired, to a very good approximation by a 2×2 matrix. The coupling element V0 and the difference of the rotational constants for the light and dark states (ΔB) are obtained from the plots of line position vs J(J+1) obtained. For the 141 to 51101161 and for the 141 to 62111 couplings the theoretical results are in reasonable agreement with the experimental results, no adjustable parameters being employed. For a coupling of 141 to 31161 the calculated V0 would be much too high compared with experiment (a factor of 10), the coupling involving the exchange of only three instead of four vibrational quanta. A situation in which the 141 state is coupled to the 62111 state to yield an avoided crossing and off-resonantly coupled to the 31161 state would be consistent with some experimental results and not affect the reasonable agreement of the slope difference and splitting for the avoided crossing plots.