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The 5-HT1B/D receptor agonist sumatriptan has been proposed to treat dyspeptic symptoms, because it facilitates gastric accommodation. It is unknown whether stimulation of 5-HT1B/D receptors is involved. Thus, in four conscious dogs, we compared the effects of sumatriptan alone or combined with N-[4-methoxy-3-(4-methyl-1-piperazinyl) phenyl]-2′-methyl-4′-(5-methyl-1,2,4-oxadiazol-3-yl)-[1,1-biphenyl]-4-carboxamide hydrocloride (GR-127935), N-[3-[3 (dimethylamino)-ethoxy]-4-methoxyphenyl]-2′-[methyl-4′-(5-methyl-1,2,4-oxadiazol-3-yl)]-[1,1-biphenyl]-4-carboxamide hydrocloride (SB-216641 hydrochloride), or 3-[4-(4-chloro-phenyl)piperazin-1-yl]-1,1-diphenyl-2-propanol hydrochloride (BRL-15572 hydrochloride) (respectively, nonselective 5-HT1B/D, selective 5-HT1B, and selective 5-HT1D receptor antagonists) on gastric accommodation to isobaric distensions performed with a barostat. An exponential and a linear model were used to fit the pressure-volume relationship. An exponential equation fitted the data better than a linear equation. Sumatriptan (800 nmol/kg iv) induced an immediate gastric relaxation (Δvolume: 112 ± 44 ml, P < 0.05). After sumatriptan, the pressure-volume curve was shifted toward significantly higher volumes. This effect was fully reversed by GR-127935 or SB-216641 but not by BRL-15572. In conclusion, 5-HT1B receptors seem to play an important role in modulating gastric accommodation to a distending stimulus. An exponential model for pressure-volume curves fits well with the concept of gastric adaptive relaxation.

Acetylcholine and tachykinins act as co-transmitters along excitatory pathways at different gut levels. Since cholinergic pathways are involved in maintaining gastric tone during fasting, our aim was to study the possible role of tachykininergic pathways in modulating canine gastric tone and compliance in vivo by using selective tachykinin receptor antagonists. In four fasting, conscious dogs, we characterized the pressure-volume relationship in the proximal stomach by using a barostat. We increased the pressure of the intragastric bag by 2 mmHg increments every 3 min, starting from a baseline value of 2 up to 12 mmHg. Drug effects were investigated by studying pressure-volume relationships before and 15 min after intravenous (i.v.) administration of SR140333, SR48968, or SR142801 (respectively, NK (1)-, NK (2)-, and NK (3)-receptor antagonist, each at the dose of 1 mg kg (-1)) or atropine (100 microg kg (-1)). Pressure-volume curves were fitted by nonlinear regression analysis. Before drug administration, the curve that best fitted the pressure-volume relationship was exponential. SR140333, SR48968 and SR142801 did not affect baseline gastric tone or the gastric pressure-volume curve at any distension level. At a distending pressure of 6 mmHg, the Delta volumes obtained after administration of SR140333, SR48968 or SR142801 vs control were 65 +/- 28, 27 +/- 26, 14 +/- 20 ml, respectively. The same was true even when all three antagonists were administered together to achieve simultaneous blockade of all three tachykinin receptor subtypes. Atropine increased baseline gastric volume (Delta volume = 237 +/- 15 ml; P0.01) and significantly (P0.0001) shifted the pressure-volume curve to the left. After atropine, a linear equation best fitted the pressure-volume curve. We conclude that tachykininergic pathways are not involved in modulating canine gastric tone and compliance during fasting, whereas cholinergic pathways play a major role not only in maintaining gastric tone, but also in modulating the compliance of the proximal stomach to a distending stimulus.

Gamma ray transitions de-exciting states in the N = Z nucleus 70Br have been identified for the first time using the GASP and EUROBALL arrays coupled with ancillary detectors. The level scheme of 70Br has been established by means of particle-gated γ-γ and γ-γ-γ coincidences. The Coulomb energy differences between isobaric analogue states in 70Br and 70Se show a deviation from the expected behaviour which could be related to dripline effects.

Thermal neutron activation and fast neutron scattering are known to be a useful tool to detect hidden explosives which present an elevated concentration of nitrogen and peculiar elemental ratio for light elements (C, N, O). Such characteristics can be suitably optimized to detect the small amount of explosives contained in anti-personnel mines (APM) disseminated in former war theatres. We report here on a research program aimed at defining a conceptual design of a field operated system for APM detection based on neutron induced reactions. ( 1999 Elsevier Science B.V. All rights reserved.

Properties of medium mass nuclei having excitation energies of 1.5 to 6 MeV/u have been probed in measurements of the multiplicities and energy spectra of emitted particles and fragments. The particle spectra indicate a progressive reduction of both the level density parameter, a, and the emission barriers as the excitation energy is increased. The evolution of the dominant de-excitation modes, observed with increasing excitation energy, is found to be qualitatively consistent with the predictions of statistical models. There is, however, evidence that dynamics may play an important role in fragment emission processes. At energies of 6 MeV/u multifragment emission is an important process. Varying theoretical models predict such multifragment events but differ in their predictions of the probability of such events.

Light charged-particle emission and neutron emission have been measured for the fusion-evaporation and fusion-fission channels in the $^{60}\mathrm{Ni}$${+}^{100}$Mo reaction at 550 and 655 MeV bombarding energies. Temperatures, emission barriers, and multiplicities for the particles detected in coincidence with evaporation residues and fission fragments have been determined. For the evaporation residue data, the ``first-chance'' spectra of particles emitted from the compound nucleus have been isolated and the same initial temperature for the different evaporated particles has been extracted. The inverse level density parameter K=A/a reaches a value of 13.8\ifmmode\pm\else\textpm\fi{}0.7 MeV at ${\mathit{E}}_{\mathrm{th}}$\ensuremath{\simeq}236 MeV. A decrease of the apparent emission barriers for the charged-particle emission at high excitation energy suggests dynamical effects on the de-excitation process. Analysis of the fissionlike events shows a saturation of light particle emission from the fission fragments. Using the average energies and multiplicities of the emitted neutrons, and charged particles, it has been found that for both initial excitation energies, 251 and 293 MeV, scission occurs at an excitation energy \ensuremath{\simeq}140 MeV. For both fusion evaporation and fusion fission, the light charged particles are preferentially emitted during the early part of the de-excitation cascade. Statistical models and dynamical calculations have been used in an attempt to interpret the experimental data.

Charged particles and high energy \ensuremath{\gamma} rays from the decay of the $^{156}\mathrm{Er}$ compound nucleus populated at ${\mathit{E}}_{\mathit{x}}$=47 MeV excitation energy by the $^{12}\mathrm{C}$${+}^{144}$Sm and $^{64}\mathrm{Ni}$${+}^{92}$Zr reactions have been measured to study possible nonstatistical or entrance channel effects. The experimental spectra and published evaporation residue and neutron data are compared with statistical model calculations. The comparison shows that the statistical model with standard parametrization of level density and yrast lines describes reasonably well the bulk of experimental observables but not the shape of neutron spectra if account is taken of the enhancement factor for E2 transitions. The discrepancies between experimental data and model calculations are discussed.

5-Hydroxytryptamine (5-HT)4 receptor agonists stimulate gut motility through cholinergic pathways, although there are data suggesting that noncholinergic (tachykininergic) excitatory pathways may also be involved. Differences may exist between the small bowel and colon. Our aims were: (i) to compare the prokinetic effect exerted by the 5-HT4 receptor agonist ML10302 in the canine small bowel and colon in vivo; and (ii) to investigate the role of tachykininergic pathways in mediating this response. In fasting, conscious dogs, chronically fitted with electrodes and strain-gauge force transducers along the small bowel and colon, intravenous injection of ML10302 (35 microg kg-1) immediately stimulated spike activity and significantly increased propagated myoelectrical events at both intestinal levels. In the small bowel, the effects of ML10302 were unchanged by previous administration of the selective NK1 tachykinin receptor antagonist SR140333, the NK2 tachykinin receptor antagonist SR48968, or the NK3 tachykinin receptor antagonist SR142801. In the colon, all tachykinin receptor antagonists significantly inhibited stimulation of spike and mechanical activity by ML10302, without affecting ML10302-induced propagated myoelectrical events. Atropine (100 microg kg-1 i.v.) suppressed the stimulatory effect of ML10302 at both intestinal levels. In conclusion, the 5-HT4 receptor agonist ML10302 induced significant prokinesia both in the small bowel and colon through activation of cholinergic pathways. Tachykininergic pathways are not involved in the ML10302-induced prokinesia in the small bowel, but they play an important role in mediating the colonic motor response to ML10302.

Four $\ensuremath{\gamma}$-ray transitions belonging to the ground state band of the $N=Z$ nucleus ${}^{88}\mathrm{Ru}$ are reported for the first time. The reaction ${}^{58}\mathrm{Ni}{(}^{32}\mathrm{S},2n\ensuremath{\gamma})$ at 105 MeV has been used, and the prompt $\ensuremath{\gamma}$ rays were detected with the GASP array. The assignment of $\ensuremath{\gamma}$ rays to ${}^{88}\mathrm{Ru}$ was made by combining information from GASP, the ISIS silicon ball, and the n-Ring neutron detector. The ${}^{88}\mathrm{Ru}$ nucleus is weakly deformed, with an ${E(2}^{+})$ energy of 0.616 MeV and ${E(4}^{+}{)/E(2}^{+})$ ratio of 2.30. The evolution of the nuclear structure along the $N=Z,$ $N=44,$ and $Z=44$ lines is discussed. Unlike in other nuclei from the region, no sign of backbending is seen in ${}^{88}\mathrm{Ru}$ at a rotational frequency of $\ensuremath{\approx}0.5 \mathrm{MeV},$ which might be a signature of the $T=0$ neutron-proton pairing in the $N=Z$ nuclei.

The first identification of gamma-rays from excited states of the 85 Mo and 88 Ru nuclei is reported, together with a short discussion of the evolution of the nuclear structure along the N = Z and the N = 43, 44 lines.

Nuclear techniques employing neutrons have proved to be a useful tool in the identification of commonly used explosives which present an elevated concentration of nitrogen. Characteristic γ-rays emitted in the thermal neutron capture reaction or in the fast neutron inelastic excitation of nitrogen nuclei have been proposed as the signature to identify hidden explosives. Compared to the other proposed non-nuclear techniques, the nuclear sensor is the only one allowing to discriminate mines from other underground objects. The present challenge is to conceive a cost-effective, mobile detection system based on nuclear techniques which can be operated, in connection with other non-nuclear sensors, by non-specifically trained personnel in field conditions. We have started a detailed study to conceive a mobile system to detect small quantities of hidden explosives using modern technology in order to improve the overall effectiveness from the point of view of efficiency, costs and transportability. To this end we are proceeding to test a number of CsI(Tl) scintillators assembled with a photodiode readout and dedicated surface mounted fast front-end electronics. We are testing neural-network based decision algorithms for on-line analysis of the signals. Finally we are planning to test a mixed (thermal and fast neutron) technique in order to reduce both the scanning time and the false alarm rates.

We have shown that two of the most studied models of lineal gravities - Liouville gravity and a ``string-inspired'' model exhibiting the main characteristic features of a black-hole solution - can be formulated as gauge invariant theories of the Poincar\'e group. The gauge invariant couplings to matter (particles, scalar and spinor fields) and explicit solutions for some matter field configurations, are provided. It is shown that both the models, as well as the couplings to matter, can be obtained as suitable dimensional reductions of a 2+1-dimensional ISO(2,1) gauge invariant theory., Comment: TeX Manuscript, 30 pages

Following the general method discussed in Refs.[1,2], Liouville gravity and the 2 dimensional model of non-Einstenian gravity ${\cal L} \sim curv^2 + torsion^2 + cosm. const.$ can be formulated as ISO(1,1) gauge theories. In the first order formalism the models present, besides the Poincar\'e gauge symmetry, additional local symmetries. We show that in both models one can fix these additional symmetries preserving the ISO(1,1) gauge symmetry and the diffeomorphism invariance, so that, after a preliminary Dirac procedure, the remaining constraints uniquely satisfy the ISO(1,1) algebra. After the additional symmetry is fixed, the equations of motion are unaltered. One thus remarkably simplifies the canonical structure, especially of the second model. Moreover, one shows that the Poincar\'e group can always be used consistently as a gauge group for gravitational theories in two dimensions., Comment: 13 pages, plain \TeX

We consider the interaction of (2+1)-dimensional fermions with a background of a charged-vortex solution of the Chern-Simons-Higgs model. When the fermions are coupled in the minimal way to the vortex gauge fields, the interaction potentials contain short-range terms, related to the vortex electric and magnetic field, and long-range terms, proportional to the topological charge of the vortex, that modify the centrifugal barrier. As a consequence of this inverse-square tail, at a large distance from the center of the vortex, the fermion behaves as if it had an effective angular momentum that, because of the difference between the fermion charge {ital e} and the scalar charge {ital q}, can assume any rational value. We develop a procedure to study the scattering of low-energy fermions by any kind of vortex and with a partial-wave analysis we compute, for any value of the fermion angular momentum, the phase shifts, the Jost functions, and the scattering cross sections. The obtained results crucially depend on the quantity {ital en}/{ital q} ({ital n} being the vorticity) and the low-energy cross section diverges at zero momentum.

Inclusive neutron spectra from the decay of [sup 156]Er compound nucleus populated at [ital E][sub [ital x]]=47 MeV excitation energy by the [sup 12]C+[sup 144]Sm and [sup 64]Ni+[sup 92]Zr reactions have been measured. The neutron spectra from the [sup 64]Ni-induced reaction are strongly contaminated by other reactions different from fusion evaporation so that inclusive spectra cannot be used to test nonstatistical or entrance channel effects in the compound nucleus decay.

High spin states of 146 Dy above the 10+ isomer have been identified by means ofγ- recoil andγ }-γ coincidences through the reaction90 Zr(58 Ni, 2pat a bombarding energy of 250 Me V. The level scheme is discussed in terms of the coupling of 2h11/2 protons to the N=80 core vibrations.

High-spin states in130Sm were populated in the reaction114Cd(29Si,4n) at a bombarding energy of 128 MeV. Subsequent de-excitation was studied using γ-ray spectroscopic methods. The change of the level patterns in the odd-even nuclei around N=78 is discussed.

Search for neutron emission from a titanium-deuterium system has been performed in a wide temperature range (from 77 K to 1100 K), with a D/Ti atomic percentage up to 165%. The sample was continuously monitored for 40 days, both at constant temperature and in nonequilibrium conditions. No neutron emission above background was observed.

A simple general argument is given to show that the counterterms in the space-like planar gauge with the Cauchy principal value prescription for the spurious singularities are local. This result is used to obtain limitations on the number and on the kind of nonlocal counterterms occurring in the light-cone case with the Mandelstam-Leibbrandt prescription.

The “first chance” spectra of light charged particles and neutrons emitted from 160Yb produced in the 60Ni+100Mo reaction have been isolated. The same initial temperature for the different evaporated particles and a decrease of the Coulomb barriers for the charged particles are observed. The inverse level density parameter K= A/ a reaches a value of 13.8±0.7 MeV at ETH≈236 MeV, confirming the decrease of the parameter a at excitation energies above 150 MeV.

Energy level of89Y were populated by the89Y(n, n′ γ) reaction at neutron energies between 2.2 and 4.8 MeV. A time-gated (HP)Ga spectrometer was used to detect the de-excitation γ-rays. Forty-three levels through 4537 keV excitation energy were identified in this way, two of which were previously unreported. Spins and parities were determined within the framework of the statistical theory from the angular distributions and excitation functions of the observed γ-rays. A complete level and decay scheme for89Y up to an excitation of 4.32 MeV is presented.

The scheme of t he energy levels of 5"Co, r epor t ed in the compi la t ion of KI~f (~), ~s reasonably wel l -es tabl ished up to an exc i t a t ion energy of ~bout 4 ~ e V , especia l ly th rough the da ta ob ta ined f rom (p, p ' ) measurements , as descr ibed in the previous compi la t ion of VERVlEE (*). On the o ther hand, the decay modes and the b ranch ing rat ios, de te rmined by means of the 58Fe(p, ~()~9Co (3), ~"Co(n, n'u (4), 56Fe(cr p~,)~gCo (~) react ions, are well de te rmined for exc i ta t ion energies below 2.5 !Y[eV. In order to imp rove th is knowledge, we carr ied out measuremen t s of t he ~gCo(n, n'y)59Co reac t ion up to an inc iden t -neu t ron energy of 3.9 MeV, as p~r t of a research p rogram concerning (n, n 'y) measuremen t s in med ium weight nuclei(~). Recent ly , LE CL~II~E et al. (~) h a v e p roduced a s tudy on th is sume react ion , describing the decay scheme up to an energy o~ 3 MeV and also p rov id ing a eompurison of the expe r imen ta l resul ts w i th t he s ta t i s t ica l t heo ry of t he compound nucleus. In th i s le t ter , we presen t our results , cover ing the energy in t e rva l s tud ied in (~), and ex tend ing t h e energy range to 3.9 MeV. Our measu remen t s were t aken at inc iden t -neu t ron energies of 1.3, 1.6, 1.8, 2.0, 2.3, 2.5, 2.7, 2.9, 3.1, 3.3, 3.5, 3.7 and 3.9 MeV, us ing the pulsed 7 MV Van de Graaff

The24Mg(3He, n)26Si and28Si(3He, n)30S two-nucleon stripping reactions were studied at incident energies ofE3He=4.7 and 5.5 MeV, using the pulsed-beam time-of-flight technique. The angular distributions were obtained in an angular range from θL=0° to θL=150° (in the laboratory system) for the neutrons from the ground state (Jπ=0+), the first excited state (Jπ=2+,Ex=1.79 MeV) and the second excited state (Jπ=2+,Ex=2.78 MeV) of26Si; and for the neutrons from the ground state (Jπ=0+) and the first excited state (Jπ=2+,Ex=2.21 MeV) of30S. A description of the results is presented in terms of the distorted-wave Born approximation and compound nucleus formalism and relative spectroscopic factors are deduced for the various levels concerned with the measurements.

The lattice disorder produced by 42-keV and 75-keV Hg ions implanted in Silicon at room temperature and the lattice location of the Hg atoms were studied by means of the channeling technique with a 2.0 MeV 4He+ beam. The damage produced was found to increase linearly with ion dose until a saturation value, connected to the ion range, is reached. The number of Si atoms displaced for Hg ion implanted was evaluated and compared with the theoretical expectation. The substitutional Hg fraction is connected to the disorder produced: the replacement mechanism is discussed.

A measurement of the angular distribution of neutrons elastically scattered from carbon-12 at 1.98 to 4.64 MeV, where the elastic scattering is the only energetically allowed reaction channel for the outgoing neutrons, is presented. Differential cross sections and resonances are also found. The purpose is to improve the experimental data and to present a phase shift and an optical model analysis of the results. (JFP)

The energy dependence of lattice disorder produced by implanting Hg ions of energy 10 to 200 keV into Si crystals has been studied at room temperature. The damage produced has been studied by means of the channeling technique with 2.0 and 3.0 MeV 4He+ beams. The number of Si atoms displaced per implanted ion has been observed to increase linearly with the implantation energy over the whole range studied, in agreement with the Kinchin-Pease theory. The slope of this linear relationship is (53 ± 6) keV−1. The penetration depth of lattice disorder produced by Hg200, Xe131, and Kr84 in Si and Hg200 implanted in Ge has been measured in the energy interval 10 to 200 keV. A comparison is presented between the disorder penetration depth and the implanted ion range. Die Energieabhangigkeit der Gitterfehlordnung durch Implantation von Si-Kristallen mit Hg-Ionen mit Energien zwischen 10 und 200 keV wird bei Raumtemperatur untersucht. Die Strahlenschaden werden durch die channeling-Technik mit 2,0 und 3,0 MeV 4He+-Strahlen untersucht. Es wird beobachtet, das die Zahl der verlagerten Si-Atome pro eingeschossenes Ion linear mit der Teilchenenergie im gesamten untersuchten Energiebereich in Ubereinstimmung mit der Theorie von Kinchin und Pease ansteigt. Die Neigung dieser linearen Abhangigkeit ist (53 ± 6) keV−1. Die Eindringtiefe der Gitterfehlordnung, von eingeschossenen Hg200-, Xe131- und Kr84-Ionen in Si und Hg200-Ionen in Ge hervorgerufen, wird fur Energien zwischen 10 und 200 keV gemessen. Es wird ein Vergleich zwischen der Eindringtiefe der Fehlordnung und dem Durchdringungsvermogen der eingeschossenen Ionen durchgefuhrt.

The heat capacities and the dynamics of hot medium mass nuclei have been explored by studies of light particle emission. The variation in heat capacity with temperature, expressed in terms of an effective Fermi gas level density parameter appropriate to the statistical description of nuclear de-excitation, corresponds to a decrease in a from A/8 to A/13 as the excitation energy increases from 1 to 2 MeV/nucleon. This result is compared to recent theoretical predictions. An apparent sudden change in the heat capacity observed at slightly higher excitation energies per nucleon is also discussed. Prescission and post-scission particle multiplicities and temperatures in coincidence with evaporation residues and fission fragments provide further information on the decay dynamics of hot nuclei. Possible means of isolating presaddle emission and of determining the temperature dependence of the fission barrier are discussed.

The influence of plasma lipid disorders on red blood cell (RBC) lipid pattern and some related erythrocyte membrane functions, such as glycerol (GLT50) permeability and erythrocyte deformability was studied in diabetes mellitus. Significantly higher red blood cell cholesterol content, GLT50 and erythrocyte filtration time values were found in diabetics. GLT50 values were found closely related to both RBC cholesterol content (r = 0.84, p less than 0.001) and filtration time (r = 0.60, p less than 0.001). Interestingly, six diabetics with retinopathy showed GLT50 values above 60 sec. The RBC Cholesterol/Phospholipids molar ratio was significantly higher in diabetics. The most notable changes of plasma lipid pattern in diabetics were a decrease of both plasma HDL cholesterol, phospholipids and Apolipoprotein A levels with an increase of HDL free cholesterol/phospholipids molar ratio. RBC cholesterol content was found to be inversely related to HDL esterified/free cholesterol molar ratio (r = -0.56, p less than 0.001), while RBC cholesterol/phospholipids molar ratio was significantly related to both HDL free cholesterol/phospholipids (r = 0.51, p. 0.001) and to LDL total cholesterol/phospholipids (r = 0.25, p less than 0.05). Lastly, HDL cholesterol levels were found to inversely relate to glycosylated haemoglobin values (r = -0.54, p less than 0.01).

Six patients with basal cell carcinoma of the vulva underwent differentiated surgical therapy, and their courses were evaluated. No apparent differences in survival time and absence of recurrences and metastases were observed inthe patients treated with radical vulvectomy (1 case), simple vulvectomy (3 cases) and local excision (2 cases). Conservative surgical therapy is therefore considered most indicated.

An adequate and unified classification of vulvar pathology has been difficult and continues to be a problem hard to solve, due to the difficulties in including different clinical aspects in various pathological classes. The causes of this uncertainty, as rather a multiplicity of view points, may be ascribed in particular to the extreme polymorphic nature of vulvar pathology. Our classification, in attempting to overcome arbitrary and absolute distinctions in such a polymorphic and variable field, adopts an etiological and anatomo-histological criterium which distinguishes vulvar pathology in: primary disorders, secondary disorders. It is evidently important to know and distinguish possible vulvar infections, in order to be able to identify those disorders which assume an oncogenous risk, while trying to overcome the problems of differential diagnosis.