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Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1–6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7–9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10−6to 1012electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.

High-energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. To increase the energy of the particles or to reduce the size of the accelerator, new acceleration schemes need to be developed. Plasma wakefield acceleration1–5, in which the electrons in a plasma are excited, leading to strong electric fields (so called ‘wakefields’), is one such promising acceleration technique. Experiments have shown that an intense laser pulse6–9or electron bunch10,11traversing a plasma can drive electric fields of tens of gigavolts per metre and above—well beyond those achieved in conventional radio-frequency accelerators (about 0.1 gigavolt per metre). However, the low stored energy of laser pulses and electron bunches means that multiple acceleration stages are needed to reach very high particle energies5,12. The use of proton bunches is compelling because they have the potential to drive wakefields and to accelerate electrons to high energy in a single acceleration stage13. Long, thin proton bunches can be used because they undergo a process called self-modulation14–16, a particle–plasma interaction that splits the bunch longitudinally into a series of high-density microbunches, which then act resonantly to create large wakefields. The Advanced Wakefield (AWAKE) experiment at CERN17–19uses high-intensity proton bunches—in which each proton has an energy of 400 gigaelectronvolts, resulting in a total bunch energy of 19 kilojoules—to drive a wakefield in a ten-metre-long plasma. Electron bunches are then injected into this wakefield. Here we present measurements of electrons accelerated up to two gigaelectronvolts at the AWAKE experiment, in a demonstration of proton-driven plasma wakefield acceleration. Measurements were conducted under various plasma conditions and the acceleration was found to be consistent and reliable. The potential for this scheme to produce very high-energy electron bunches in a single accelerating stage20means that our results are an important step towards the development of future high-energy particle accelerators21,22.

Un nombre croissant de services de médecine nucléaire s’équipent d’automates pour la préparation des médicaments radiopharmaceutiques, dans le but principal de minimiser l’irradiation du personnel. Cependant, la mesure automatique de l’activité prescrite au patient diffère de la méthode manuelle du point de vue méthodologique et instrumental. Dans ce contexte, l’objectif de cette étude était de tester les performances d’un de ces automates, l’Unidose de TRASIS®, dans deux centres hospitaliers récemment équipés, à travers la réalisation d’une série de contrôle qualité. La particularité de ces automates est qu’ils sont composés de deux activimètres : l’activimètre d’entrée (composé d’une chambre à puits) et l’activimètre de sortie (composé d’une sonde). Les contrôles ont été réalisés sur ces deux activimètres. Les résultats trouvés, ainsi que la méthodologie de mesure, ont été ensuite comparés aux exigences réglementaires en vigueur en France. Les résultats trouvés sont cohérents entre les deux sites et ont mis en évidence plusieurs non-conformités par rapport à la réglementation en vigueur, une partie desquelles concernant l’activimètre de sortie utilisé pour la mesure de l’activité de la carpule qui est en réalité une sonde. Ces résultats soulèvent la question d’une réglementation adaptée aux nouveaux systèmes de mesure automatisés en médecine nucléaire.

The merger of two neutron stars is predicted to give rise to three major detectable phenomena: a short burst of γ-rays, a gravitational-wave signal, and a transient optical–near-infrared source powered by the synthesis of large amounts of very heavy elements via rapid neutron capture (the r-process). Such transients, named ‘macronovae’ or ‘kilonovae’, are believed to be centres of production of rare elements such as gold and platinum. The most compelling evidence so far for a kilonova was a very faint near-infrared rebrightening in the afterglow of a short γ-ray burst at redshift z = 0.356, although findings indicating bluer events have been reported. Here we report the spectral identification and describe the physical properties of a bright kilonova associated with the gravitational-wave source GW170817 and γ-ray burst GRB 170817A associated with a galaxy at a distance of 40 megaparsecs from Earth. Using a series of spectra from ground-based observatories covering the wavelength range from the ultraviolet to the near-infrared, we find that the kilonova is characterized by rapidly expanding ejecta with spectral features similar to those predicted by current models. The ejecta is optically thick early on, with a velocity of about 0.2 times light speed, and reaches a radius of about 50 astronomical units in only 1.5 days. As the ejecta expands, broad absorption-like lines appear on the spectral continuum, indicating atomic species produced by nucleosynthesis that occurs in the post-merger fast-moving dynamical ejecta and in two slower (0.05 times light speed) wind regions. Comparison with spectral models suggests that the merger ejected 0.03 to 0.05 solar masses of material, including high-opacity lanthanides.

To go further in the optimization of treatment planning in selective internal radiation therapy (SIRT), radiobiological aspects can be accounted for with the OEDIPE software and used to design fractionation protocols. Dosimetry was performed using data from 99mTc-MAA evaluations of 10 patients treated for hepatic metastases with SIRT. The maximal injectable activity (MIA) was calculated, using a tolerance criterion on BEDmean,healthyliverequal to 54 Gy2.5, for different fractionation protocols, varying the number of fractions, the repartition of activity and the time delay between fractions. OEDIPE was also used to calculate BEDmeanand the EUD to the tumoral liver (TL) that would be delivered with those MIAs. Compared with a single-injection protocol, the MIA is increased on average by 23% ±3%, 36% ±5% and 45% ±7% for fractionation protocols with 2, 3 and 4 equal fractions, respectively, while BEDmean,TLis increased by 15% ±2%, 23% ±4% and 29% ±5%. EUDTL, calculated for one evaluation, is increased by 51%, 115% and 159% using 2, 3 and 4 equal fractions, respectively. For this evaluation, the optimal activity repartition for two-fraction protocols is (3/4 −1/4) for time delays of less than 4 days, (2/3 −1/3) for time delays between 4 and 6 days and (1/2 −1/2) for time delays superior to 6 days. Finally, this study confirmed that OEDIPE can be regarded as a tool for treatment planning optimization and fractionation protocol design in SIRT.

For targeted radionuclide therapies, treatment planning usually consists of the administration of standard activities without accounting for the patient-specific activity distribution, pharmacokinetics and dosimetry to organs at risk. The OEDIPE software is a user-friendly interface which has an automation level suitable for performing personalized Monte Carlo 3D dosimetry for diagnostic and therapeutic radionuclide administrations. Mean absorbed doses to regions of interest (ROIs), isodose curves superimposed on a personalized anatomical model of the patient and dose-volume histograms can be extracted from the absorbed dose 3D distribution. Moreover, to account for the differences in radiosensitivity between tumoral and healthy tissues, additional functionalities have been implemented to calculate the 3D distribution of the biologically effective dose (BED), mean BEDs to ROIs, isoBED curves and BED-volume histograms along with the Equivalent Uniform Biologically Effective Dose (EUD) to ROIs. Finally, optimization tools are available for treatment planning optimization using either the absorbed dose or BED distributions. These tools enable one to calculate the maximal injectable activity which meets tolerance criteria to organs at risk for a chosen fractionation protocol. This paper describes the functionalities available in the latest version of the OEDIPE software to perform personalized Monte Carlo dosimetry and treatment planning optimization in targeted radionuclide therapies.

Context. GRB060614 observations by VLT and by Swift have infringed the traditionally accepted gamma-ray burst (GRB) collapsar scenario that purports the origin of all long duration GRBs from supernovae (SN). GRB060614 is the first nearby long duration GRB clearly not associated with a bright Ib/c SN. Moreover, its duration (T90~ 100 s) makes it hardly classifiable as a short GRB. It presents strong similarities with GRB970228, the prototype of a new class of “fake” short GRBs that appear to originate from the coalescence of binary neutron stars or white dwarfs spiraled out into the galactic halo.

Context. The cosmological origin of gamma-ray bursts (GRBs) has been firmly established, with redshifts up to $z = 6.29$. They are possible candidates for use as “distance indicators” for testing cosmological models in a redshift range hardly achievable by other cosmological probes. Asserting the validity of the empirical relations among GRB observables is now crucial for their calibration.

Context.The discovery by Swiftand HETE-2 of an afterglow emission associated possibly with short GRBs opened the new problematic of their nature and classification. This issue has been further enhanced by the observation of GRB 060614 and by a new analysis of the BATSE catalog which led to the identification of a new class of GRBs with “an occasional softer extended emission lasting tenths of seconds after an initial spikelike emission”.

Context.The Swiftsatellite has given continuous data in the range 0.3–150 keV from 0 s to 106s for GRB 060218 associated with SN2006aj. This Gamma-Ray Burst (GRB) which has an unusually long duration ($T_{90}\sim 2100$s) fulfills the Amati relation. These data offer the opportunity to probe theoretical models for GRBs connected with Supernovae (SNe).

This article presents the results of a broader clinical research into the effectiveness of integrated treatments in teenage eating disorders, carried out at the Complex Operative Unit of Psychotherapy (Unità Operativa Complessa or U.O.C.) of the Department of Psychiatric Sciences and Psychological Medicine in collaboration with the Department of Neuropsychiatric Science for Child Development (Dipartimento di Scienze Neuropsichiatriche dell’Età Evolutiva), both at the “La Sapienza” University of Rome. The hypothesis of this research project is that in diagnosticable situations such as anorexia or bulimia, an integrated and multidisciplinary treatment, which combines medical-nutritional interventions and family psychotherapy, allows better results than a single kind of treatment, which is the usual medical- nutritional intervention supported by psychiatric counselling. Twenty-eight cases (16 of bulimia and 12 of anorexia) were selected and then subdivided, with a randomized distribution, into two (experimental and control) homogeneous groups of 14 patients. The grouping variables were the diagnosis, the disorder’s seriousness and duration, BMI, gender, age, family composition and social status. The variables which have been examined in this article are the clinical parameters, which were valuated in accordance with the DSM IV-TR criteria, and relational parameters which were explored through the use of the W.F.T. Test (Wiltwyck Family Tasks). These parameters were tested at beginning as well as at the end of the therapies, in both the experimental group and the control group. Statistical analysis has shown that the experimental group, which was followed with the integrated treatment, experienced a significant improvement of the parameters as related to dysfunctional family interaction modalities, and that this improvement was correlated to the positive evolution of the clinical parameters. This improvement was not present or not of the same degree in the control group. The results, moreover, demonstrate the effectiveness of an integrated systemic treatment based on a complex approach compared to a reductionist approach.

Context. GRB060614 observations by VLT and by Swift have infringed the traditionally accepted gamma-ray burst (GRB) collapsar scenario that purports the origin of all long duration GRBs from supernovae (SN). GRB060614 is the first nearby long duration GRB clearly not associated with a bright Ib/c SN. Moreover, its duration (T90~ 100?s) makes it hardly classifiable as a short GRB. It presents strong similarities with GRB970228, the prototype of a new class of ?fake? short GRBs that appear to originate from the coalescence of binary neutron stars or white dwarfs spiraled out into the galactic halo.Aims. Within the ?canonical? GRB scenario based on the ?fireshell? model, we test if GRB060614 can be a ?fake? or ?disguised? short GRB. We model the traditionally termed ?prompt emission? and discriminate the signal originating from the gravitational collapse leading to the GRB from the process occurring in the circumburst medium?(CBM).Methods. We fit GRB060614 light curves in Swift's BAT (15?150?keV) and XRT (0.2?10?keV) energy bands. Within the fireshell model, light curves are formed by two well defined and different components: the proper-GRB (P-GRB), emitted when the fireshell becomes transparent, and the extended afterglow, due to the interaction between the leftover accelerated baryonic and leptonic shell and the CBM. Results. We determine the two free parameters describing the GRB source within the fireshell model: the total e?plasma energy (Etote?= 2.94?1051?erg) and baryon loading (B = 2.8?10-3). A small average CBM density ~ 10-3?particles/cm3is inferred, typical of galactic halos. The first spikelike emission is identified with the P-GRB and the following prolonged emission with the extended afterglow peak. We obtain very good agreement in the BAT (15?150?keV) energy band, in what is traditionally called ?prompt emission?, and in the XRT (0.2?10?keV) one. Conclusions. The anomalous GRB060614 finds a natural interpretation within our canonical GRB scenario: it is a ?disguised? short GRB. The total time-integrated extended afterglow luminosity is greater than the P-GRB one, but its peak luminosity is smaller since it is deflated by the peculiarly low average CBM density of galactic halos. This result points to an old binary system, likely formed by a white dwarf and a neutron star, as the progenitor of GRB060614 and well justifies the absence of an associated SN Ib/c. Particularly important for further studies of the final merging process are the temporal structures in the P-GRB down to 0.1?s.

Context. The cosmological origin of gamma-ray bursts (GRBs) has been firmly established, with redshifts up to z = 6.29. They are possible candidates for use as ?distance indicators? for testing cosmological models in a redshift range hardly achievable by other cosmological probes. Asserting the validity of the empirical relations among GRB observables is now crucial for their calibration. Aims. Motivated by the relation proposed by Amati and collaborators, we look within the ?fireshell? model for a relation between the peak energy Epof the ?F?total time-integrated spectrum of the afterglow and the total energy of the afterglow Eaft, which in our model encompasses and extends the prompt emission. Methods. The fit within the fireshell model, as for the ?canonical? GRB?050315, uses the complete arrival time coverage given by the Swift satellite. It is performed simultaneously, self-consistently, and recursively in the four BAT energy bands (15?25?keV, 25?50?keV, 50?100?keV, and 100?150?keV), as well as in the XRT one (0.2?10?keV). It uniquely determines the two free parameters characterizing the GRB source, the total energy Ee?totof the e?plasma and its baryon loading?B, as well as the effective CircumBurst Medium (CBM) distribution. We can then build two sets of ?gedanken? GRBs varying the total energy of the electron-positron plasma Ee?totand keeping the same baryon loading?B of GRB?050315. The first set assumes the one obtained in the fit of GRB?050315 for the effective CBM density. The second set assumes instead a constant CBM density equal to the average value of the GRB?050315 prompt phase. Results. For the first set of ?gedanken? GRBs we find a relation Ep?(Eaft)a, with a = 0.45 ?0.01, whose slope strictly agrees with the Amati one. Such a relation, in the limit B ?10-2, coincides with the Amati one. Instead, no correlation is found in the second set of ?gedanken? GRBs.Conclusions. Our analysis excludes the proper?GRB (P-GRB) from the prompt emission, extends all the way to the latest afterglow phases, and is independent of the assumed cosmological model, since all ?gedanken? GRBs are at the same redshift. The Amati relation, on the other hand, includes the P-GRB, focuses only on the prompt emission, being therefore influenced by the instrumental threshold that fixes the end of the prompt emission, and depends on the assumed cosmology. This might explain the intrinsic scatter observed in the Amati relation.

Feline primary osteosarcomas involving the skull are extremely rare. When they occur, orbit, mandible, and maxilla are the most common sites. Microscopically, scattered multinucleated giant cells (MGCs) are not an uncommon occurrence in osteosarcoma (OSC), but they are generally in low number. Only in a rare variant, the giant cell-rich OSC, are MGCs the prevalent cell type. Although osteoclast and osteoblast origin have been postulated in human and veterinary literature, the origin of MGCs in osteosarcomas is poorly understood. This report describes a giant cell-rich OSC in the calvarium of a 13-year-old spayed female shorthair cat. The animal exhibited a range of neurologic signs, including left circling, compulsive gait, lack of proprioception, and bilateral absence of menace reaction, with indication of left forebrain involvement. Gross lesions were characterized by a multilobate, spherical mass located in the left calvarium, compressing the left forebrain. Histologically, the tumor was characterized by scattered nests of MGCs separated by small bundles of pleomorphic, fusate to polygonal cells. Between spindle cells, osteoid was very sparse and arranged in thin strands. immunohistochemical stains for vimentin were positive, with no detectable cellular staining for cytokeratin, S-100 protein, or Class II major histocompatibility complex. Ultrastructurally, MGCs contained profiles of rough endoplasmic reticulum; no lysosomes were observed. The origin of MGCs in osteosarcoma remains obscure, and our results confirm their ambiguous identity.

We retrospectively evaluated the epidemiology of onychomycosis and/or paronychia in 172 patients attending the Clinic of Dermatology and Venereology over a 5 year period. Although yeast isolates, belonging to the Candidaspecies, represented the most frequent etiologic agents of these infections, an increasing prevalence of fungal infections due to emerging fungal pathogens (EFP) was noted throughout this time period. In particular, EFP as causative agents of these infections increased from 0 to 28.4% from 1998 to 2002.

Children born small for gestational age (SGA) may present advanced bone maturation in childhood and reduced final height. The objectives of the study were to evaluate adrenarche, pubertal development, age at menarche and final height in full-term born-SGA girls. Twenty-four girls (12 born-SGA and 12 matched controls) were evaluated at 6-7.5 years of age for clinical signs of puberty and dehydroepiandrosterone sulfate (DHEAS) levels, as a marker of adrenarche. Thirty-eight girls (19 born-SGA and 19 matched controls) were evaluated at 17.5-18.5 years of age to assess final height, sexual maturation and age at menarche. SGA girls had a mean final height (160.1 cm vs 165.8 cm, p < 0.01) and mean weight (52.1 kg vs 56.5 kg, p < 0.05) significantly lower than controls. Controls had a mean final height significantly higher than their mean target height. Sexual maturation was at stage 5 of Tanner's staging in SGA girls and control subjects. SGA girls had a slightly anticipated puberty (9.9 vs 10.4 years for initial breast development) and a lower age at menarche (11.9 vs 12.3 years). At 6-7.5 years of age, SGA females and controls did not show any difference for clinical signs of puberty; however, DHEAS levels (0.75 + 0.18μg/ml vs 0.57 + 0.22μg/ml, p < 0.05) were significantly higher in SGA girls than in control subjects. We concluded that full-term born-SGA females have impaired final height and weight in adolescence but substantially normal sexual maturation and age at menarche. Increased DHEAS levels before puberty in born-SGA girls may predispose to increased bone maturation in childhood with a reduced final height. In our population a progressive increment in final stature is evident.

The effect of administering vitamins E (E₅₀ or E₂₀₀: 50 or 200 mg kg diet) and C (C₅₀₀ or C₁₀₀₀: 500 or 1000 mg l^-1 water) singly and in combination was verified on plasma and muscle levels of α-tocopherol and the oxidative stability of rabbit meat during display. Six groups of 10 hybrid males were fed experimental diets from 35 to 85 days of age. Productive performance and carcass drip loss were also recorded. Performance was unaffected by treatments, but drip loss was improved by simultaneous administration of the two antioxidants. The α-tocopherol levels in plasma and muscle were significantly higher in animals which simultaneously ingested the highest amounts of the two vitamins, and the oxidative processes (TBA-RS values) of their meat during storage were lower. The results confirm the synergistic action of ascorbate and the benefit of using high levels of the two vitamins to prevent oxidative stress during meat processing and storage.
© 2000 Society of Chemical Industry

The feeding of a high-fiber and low-energy diet to young rabbit does from weaning to the first kindling was used to modify their body reserves, stimulate their energy intake, and reduce the energy deficit during the first lactation. Rabbits (53 per group) were given ad libitum access to either a control or high-fiber diet (CP, 17.6 vs 15.8% of DM; crude fiber, 15.5 vs 19.9% of DM; digestible energy, 2,565 vs 2,261 kcal/kg of DM, respectively) from weaning to their first kindling. During lactation, both groups received the same diet, which contained 19.3% CP, 16.5% crude fiber, and 2,634 kcal/kg digestible energy (dry matter basis). Four comparative slaughters were performed to estimate the chemical and energy balance of rabbit does at different physiological states: at the beginning of the trial (12 rabbits, 45 d of age), at mating (10 rabbits per group, 136 d), at kindling (10 rabbits per group, 167 d), and at the end of lactation (12 and 11 rabbits for the control and the high-fiber group, 197 d). Large changes in body weight and composition were observed between slaughters. From 45 d to mating, doe body fat and energy increased 7.93 and 4.64 times the initial content, respectively. During pregnancy, body protein concentration decreased from 203 to 186 g/kg. At the end of lactation, body fat and energy concentration were reduced to values close to those measured at 45 d of age. Dietary treatment affected body chemical and energy balance during pregnancy and lactation but not reproductive and lactational performance. The high-fiber diet stimulated feed intake from weaning to the first kindling but not dietary energy intake. During lactation, the rabbits fed the high-fiber diet ate 10 kcal · d−1· kg live weight−·75more and lost less body fat (−405 vs −504 g) and body energy (−3,628 vs −4,294 kcal) than the does fed the control diet (P< .001). In the same period, all does showed water and protein retention (185 and 45 g, on average) regardless of dietary treatment. In conclusion, feeding young does a high-fiber diet until their first kindling reduced the chemical and energy body deficit at the end of the first lactation.

Neonatal hypercalcemia is a rare condition often of unclear pathogenesis. If unrecognized and untreated it may result in central nervous system and renal damage. We studied three infants with symptomatic neonatal hypercalcemia pointing out pathogenetic and therapeutic aspects. One infant was found to have transient hyper-parathyroidism with high intact parathyroid hormone (iPTH) levels. One infant had an incomplete form of Williams syndrome with hypercalcemia and an elfin facies. The pathogenesis is unclear in this case. A reduced secretion of calcitonin or an hy-persensitivity to vitamin D might be the underlying defect. The third case was found to have subcutaneous fat necrosis and hypercalcemia associated with high 1,25(OH)2D levels and suppressed iPTH levels. These findings suggest an unregulated extrarenal 1,25(OH)2D production. These infants were treated with hydratation, furosemide, corticosteroids and low calcium diet. Symptomatic neonatal hypercalcemia should be treated promptly. However blood has to be taken before starting treatment to study calcium-regulating hormones and clarify pathogenesis.

We have constructed and analyzed a group of Shigella flexneri 5 auxotrophic mutants. The wild-type strain M90T was mutagenized in genes encoding enzymes involved in the synthesis of (i) aromatic amino acids, (ii) nucleotides, and (iii) diaminopimelic acid. In this way, strains with single (aroB, aroC, aroD, purE, thyA, and dapB) and double (purE aroB, purE aroC, purE aroD, purE thyA) mutations were obtained. Although the Aro mutants had the same nutritional requirements when grown in laboratory media, they showed different degrees of virulence in vitro and in vivo. The aroB mutant was not significantly attenuated, whereas both the aroC and aroD strains were severely attenuated. p-Aminobenzoic acid (PABA) appeared to be the main requirement for the Aro mutants' growth in tissue culture. Concerning nucleotides, thymine reduced the pathogenicity, whereas adenine did not. However, when combined with another virulence-affecting mutation, adenine auxotrophy appeared to potentiate that mutation's effects. Consequently, the association of either the purE and aroC or the purE and aroD mutations had a great effect on virulence as measured by the Sereny test, whereas the purE aroB double mutation appeared to have only a small effect. All mutants except the dapB strain seemed to move within a Caco-2 cell monolayer after 3 h of infection. Nevertheless, the auxotrophs showing a high intracellular generation time were negative in the plaque assay. Knowledge of each mutation's role in attenuating Shigella strains will provide useful tools in designing vaccine candidates.

The electrolytic insertion of hydrogen into palladium was investigated in the temperature range from 25 to 175°C in 85 and 100% H3PO4electrolyte. At each temperature reduction of the H3PO4molecule couples with the hydrogen evolution reaction (her): although this poses no problem to hydrogen insertion, it may lead to Pd cathode deactivation at 175°C. Electrolytically achieved H/Pd stoichiometric ratios were correlated with the corresponding equilibrium hydrogen pressure (pH2) using known isotherms of the H2–Pd system. Electrolytic insertion, equivalent to loading under high pH2at 25°C, thus loses its efficiency as temperature increases: the kinetics of the her at Pd explain such behaviour. Nevertheless, up to around 100°C, the Pd hydride electrode still achieved thermodynamic potentials which were much higher than that of H2at one atmosphere and the same temperature.

In Shigella flexneri, the ompB locus (containing the ompR and envZ genes) was found to modulate expression of the vir genes, which are responsible for invasion of epithelial cells. vir gene expression was markedly enhanced under conditions of high osmolarity (300 mosM), similar to that encountered in tissues both extra- and intracellularly. Two ompB mutants were constructed and tested for virulence and for osmotic regulation of vir genes. An envZ::Tn10 mutant remained invasive, although its virulence was significantly decreased as a result of its inability to survive intracellularly. By using a vir::lac operon fusion, this mutation was shown to decrease beta-galactosidase expression both in low- and high-osmolarity conditions but did not affect vir expression in response to changes in osmolarity. A delta ompB deletion mutant was also constructed via allelic exchange with an in vitro-mutagenized ompB locus of Escherichia coli. This mutation severely impaired virulence and abolished expression of the vir::lac fusion in both low- and high-osmolarity conditions. Therefore, a two-component regulatory system modulates virulence according to environmental conditions. In addition, the mutation affecting a spontaneous avirulent variant of S. flexneri serotype 5, M90T, has been mapped at the ompB locus and was complemented by the cloned E. coli ompB locus. Introduction of the vir::lac fusion into this mutant did not result in the expression of beta-galactosidase (Lac-).

Well‐documented cases of confirmed idiopathic epilepsy in 125 dogs were evaluated retrospectively. Forty‐six breeds (each with no sex predisposition) were examined. Although dogs of all ages were affected, the peak value for the onset of first seizure was between one and five years. Approximately 75 per cent of animals had generalised grand mal type seizures with loss of consciousness. Preictal and postictal phases were present in the majority of dogs. Interictal electroencephalographic recordings of 37 anaesthetised dogs were statistically analysed. High frequency and low amplitude paroxysmal discharges with either a focal or generalised distribution were found in the majority of these dogs. Possible causes for this variation from dog to dog were analysed. It was concluded that, despite anaesthesia, electroencephalographic features were consistent and unique in dogs with idiopathic epilepsy.

Generally the quantum efficiency of FIR Raman generation in molecular gases is below the theoretical value. This disagreement is particularly evident in Raman scattering from pulsed sources with short pulse length, when the vibrational saturation limits the power conversion. Other nonlinear processes can overcome this saturation, but they require a very intense pump power for too short a time to use the FIR radiation in high sensitive experiments with heterodyne detection. This is the case, for instance, of RFWM. In this work we describe the experimental conditions to achieve a high efficiency 90 micron Raman conversion in ammonia, with both short and long pulses.

By pumping CH3F with a high pressure tunable TE-CO2 laser, the resonant four-wave mixing process (RFWM) generates a very efficient tunable single line FIR emission at the Raman frequency. This result is strictly related to the spectroscopic structure of the CH3F molecule. By means of this process, a tunable FIR emission on a 0.1 cm-1 bandwidth 150 kW (8 mJ) single line, is obtained which can be used for many FIR multiphoton applications.

This study evaluates the effects of a Tele-check/Tele-emergency service on the quality of life in the elderly. Through telephone interviews a questionnaire has been repeatedly administered to explore various psychological, somatic, and social aspects in a random sample of 574 subjects aged 65 years and over (mean = 76.8 years). The findings suggest that the elderly helped by the service (in its ‘control’ functioning) make less demands on health facilities (GPs visits, number of days in hospital) as compared to controls. Implications are presented and discussed.

The multiphoton absorption and dissociation process of SF6irradiated by CO2laser has been experimentally studied for both collision and collisionless regimes. The absorption measurements have been performed by using the optoacustic technique, while the dissociation yield has been measured by means of a mass spectrometer. The experimental results have been discussed on the basis of a rate equation approach, including optical, collisional and dissociation processes. A satisfactory agreement has been found between experimental and theoretical results. Special emphasis is given to the importance of postlaser reaction on the overal dissociation yield.

The capacity of Shigella to spread within the cytosol of infected epithelial cells and to infect adjacent cells is critical for the development of infection foci, which lead to mucosal abscesses. Shigella is a nonmotile microorganism that appears to utilize host cell microfilaments to generate intra- as well as intercellular movements, since this movement was inhibited by cytochalasin D and involvement of F-actin was demonstrated by direct labeling of infected cells with the specific dye N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phallacidin. Such movements led to the formation of extracellular protrusions, which may explain cell to cell spread. icsA, a locus necessary for intra- and intercellular spread, was identified on the Shigella flexneri virulence plasmid pWR100. This locus was cloned and shown to express a 120-kDa outer membrane protein, which plays an important role in the interactions established between host cell microfilaments and the bacterial surface, thus leading to intracellular movement.

A CO2laser chain able to supply ≅30 MW on a single mode TEM00is described. The coupling of a modified Lumonics 101 module with a low-pressure cell constitutes the oscillator and two further Lumonics 103 stages two amplifiers. The final pulse achieves the energy of 4.0 J with 90% of this energy in a peak of 100 ns FWHM. Si descrive una catena laser a CO2che può fornire circa 30 MW sul singolo modo TEM00. L’accoppiamento di un modulo Lumonics 101 con una cella operante a bassa pressione costituisce l’oscillatore e due ulteriori stadi Lumonics 103 gli amplificatori. L’impulso finale raggiunge un’energia di 4.0 J con il 90% di questa energia contenuta in un picco largo 100 ns a metà altezza. Описывается CO2лазерная система, способная обеспечить мощность 30 МВт в одномодовом TEM00режиме. Соединение модифицированного модуля «Люмоникс 101» с ячейкой низкого давления составляет осциллятор и две дополнительные стадии «Люмоникс 103» усилителя. Резуьтирующий импульс имеет энергию 4.0 Дж, причем 90% энергии попадает в пик с шириной 100 нс на полувысоте.

Osmoregulation of the Shigella flexneri ompC gene and the role of OmpC in Shigella virulence have been investigated. OmpC was highly expressed when bacteria were grown in medium of either low or high osmolarity. This constitutive expression is in contrast with the regulation observed in Escherichia coli, in which the expression of OmpC is repressed at low osmolarity and induced at high osmolarity. In addition, the Shigella ompC gene was barely expressed by a delta ompB (delta ompR and delta envZ) mutant. We described in a previous report that such a mutant was severely impaired in virulence both in vitro and in vivo. Starting from this observation, and in order to assess which gene(s) regulated by ompR and envZ are involved in virulence, we constructed an S. flexneri delta ompC mutant. Three S. flexneri mutants, ompF'-lacZ, delta ompC, and delta ompB, were compared for virulence. The ompF'lacZ mutant behaved like the S. flexneri serotype 5 wild-type strain M90T in all in vitro and in vivo virulence tests. On the contrary, the delta ompB and delta ompC strains were considerably impaired in their virulence phenotypes. The ability of these two mutants to spread from cell to cell and to kill epithelial cells was severely affected. Consequently delta ompC, as previously described for delta ompB, was unable to elicit a positive Sereny test. The delta ompB mutant was restored to virulence by introducing a recombinant multicopy plasmid carrying the cloned E. coli ompC gene, indicating that a functional OmpC protein was necessary and sufficient to restore virulence to this mutant of S. flexneri.

The electrolytic insertion of deuterium into Pd at 95°C was investigated by a simple calorimetric technique. This involved continuous feeding of heating power to the electrolytic cell to maintain it isothermal with an external thermostatic bath: any extraneous thermal phenomenon taking place inside the cell is directly determined by the lack of balance of the original heating power input. It was thus found that Pd loading by deuterium is always paralleled by excess power generation, which largely exceeds the electrolytic power input. After prolonged electrolysis the loaded electrodes were found to continue heat generation in open circuit (o.c.) conditions. The reproducibility of the thermal phenomenon allowed its dependence on several experimental parameters to be investigated.

The present work describes a measurement of longitudinal polarization of β−electrons, emitted by a204Tl source, performed using the double Coulomb scattering technique. The observed effect is lower (by about 10%) than expected for −v/cpolarized electrons. The present results agree, within the errors, with those obtained in a previous work by measuring the circular polarization of the bremsstrahlung γ-rays,

The polarization of the external bremsstrahlung produced by the electrons emitted by204Tl near the top of the spectrum (first order unique forbidden transition) has been measured by means of the usual technique of the forward Compton scattering on magnetized iron. The observed effect agrees, within experimental error (about 10%), with the value expected for −v/cpolarized electrons.