[Artificial intelligence: An introduction for clinicians]. / Intelligence artificielle : une introduction pour les cliniciens.

Artificial intelligence (AI) is a growing field that has the potential to transform many areas of society, including healthcare. For a physician, it is important to understand the basics of AI and its potential applications in medicine. AI refers to the development of computer systems capable of performing tasks that typically require human intelligence, such as pattern recognition, learning from data, and decision-making. This technology can be used to analyze large amounts of patient data and to identify trends and patterns that can be difficult for human physicians to detect. This can help doctors to manage their workload more efficiently and provide better care for their patients. All in all, AI has the potential to dramatically improve the practice of medicine and improve patient outcomes. In this work, the definition and the key principles of AI are outlined, with particular focus on the field of machine learning, which has been undergoing considerable development in medicine, providing clinicians with in-depth understanding of the principles underlying the new technologies ensuring improved health care.

Supporting the improvement of air quality management practices: The "FAIRMODE pilot" activity.

This paper presents the first outcomes of the "FAIRMODE pilot" activity, aiming at improving the way in which air quality models are used in the frame of the European "Air Quality Directive". Member States may use modelling, combined with measurements, to "assess" current levels of air quality and estimate future air quality under different scenarios. In case of current and potential exceedances of the Directive limit values, it is also requested that they "plan" and implement emission reductions measures to avoid future exceedances. In both "assessment" and "planning", air quality models can and should be used; but to do so, the used modelling chain has to be fit-for-purpose and properly checked and verified. FAIRMODE has developed in the recent years a suite of methodologies and tools to check if emission inventories, model performance, source apportionment techniques and planning activities are fit-for-purpose. Within the "FAIRMODE pilot", these tools are used and tested by regional/local authorities, with the two-fold objective of improving management practices at regional/local scale, and providing valuable feedback to the FAIRMODE community. Results and lessons learnt from this activity are presented in this paper, as a showcase that can potentially benefit other authorities in charge of air quality assessment and planning.

Item and domain network structures of the Resilience Scale for Adults in 675 university students.

AIMS: The Resilience Scale for Adults (RSA) is a questionnaire that measures protective factors of mental health. The aim of this paper is to perform a network analysis of the RSA in a dataset composed of 675 French-speaking Belgian university students, to identify potential targets for intervention to improve protective factors in individuals. METHODS: We estimated a network structure for the 33-item questionnaire and for the six domains of resilience: perception of self, planned future, social competence, structured style, family cohesion and social competence. Node predictability (shared variance with surrounding nodes in the network) was used to assess the connectivity of items. An exploratory graph analysis (EGA) was performed to detect communities in the network: the number of communities detected being different than the original number of factors proposed in the scale, we estimated a new network with the resulting structure and verified the validity of the new construct which was proposed. We provide the anonymised dataset and code in external online materials (10.17632/64db36w8kf.2) to ensure complete reproducibility of the results. RESULTS: The network composed of items from the RSA is overall positively connected with strongest connections arising among items from the same domain. The domain network reports several connections, both positive and negative. The EGA reported the existence of four communities that we propose as an additional network structure. Node predictability estimates show that connectedness varies among the items and domains of the RSA. CONCLUSIONS: Network analysis is a useful tool to explore resilience and identify targets for clinical intervention. In this study, the four domains acting as components of the additional four-domain network structure may be potential targets to improve an individual's resilience. Further studies may endeavour to replicate our findings in different samples.

[Chronic pelvic pain syndrome and Crohn's disease : a dangerous association]. / Syndrome douloureux pelvien chronique et maladie de Crohn : une synergie dangereuse.

We present the case of a 54 year old male complaining of abdominal pain localised in the right flank and irradiating in other abdominal regions. The pain was previously associated with kidney stones, but persisted months after their total evacuation. Suffering from Crohn's disease, low dose corticosteroids likely caused a particularly invalidating chronic prostatitis, which antibiotic treatment aggravated the symptoms of Crohn's disease, therefore complicating the therapeutic care by causing a vicious circle. Further epidemiological and microbiological studies are needed in order to establish an association between low dose steroid for Crohn's disease and chronic pelvic pain syndrome.

On présente le cas d'un homme de 54 ans se plaignant d'une douleur dans le flanc droit irradiant dans d'autres régions abdominales. La douleur était précédemment associée à la présence de lithiases urinaires, mais persiste des mois après leur évacuation. Souffrant d'une maladie de Crohn, le traitement par faible dose de corticostéroïdes a vraisemblablement causé une prostatite chronique particulièrement invalidante, dont le traitement antibiotique aggrave les symptômes de la maladie de Crohn compliquant ainsi la prise en charge thérapeutique par un cercle vicieux. Des études épidémiologiques et microbiologiques plus approfondies sont nécessaire afin d'établir l'association entre le traitement stéroïde à faible dose pour la maladie de Crohn et le syndrome douloureux pelvien.

Neutron scattering observation of quasi-free rotations of water confined in carbon nanotubes.

The translational and orientational dynamics of water in carbon nanotubes has been studied by quasi-elastic neutron scattering from 300 down to 10 K. Results show that, reducing temperature below 200 K, part of this water behaves as a quasi-free rotor, that is, the orientational energy of such molecules becomes comparable to the rotational energy of water in the gas phase. This novel and unique dynamic behavior is related to the appearance of water molecules characterized by a coordination number of about two, which is promoted by sub-nanometer axial confinement. This peculiar molecular arrangement allows water to show an active rotational dynamics even at temperatures as low as 10 K. The translational mobility shows a behavior compatible with the rotational one.

Spontaneous resolution of Chiari type 1 malformation. A case report and literature review.

We describe a 62-year-old woman who presented with a history of ataxia, dizziness and urinary urgency. Neurological examination disclosed a positive Romberg sign, ataxia and postural instability. A magnetic resonance imaging (MRI) scan showed Chiari type 1 malformation (CM1). Forty-eight months later, the patient was clinically improved and underwent a second MRI examination, which showed complete resolution of the Chiari 1 malformation. Spontaneous resolution of CM1 is exceptionally rare and has to be considered in the radiological and clinical management.

Endovascular treatment of a small aneurysm of the superior cerebellar artery with a flow-diverter device. A case report.

We describe the case of a 62-year-old woman who presented with a small fusiform left superior cerebellar artery (SCA) aneurysm. Aneurysms located on the SCA are uncommon and their presentation, natural history and clinical management are poorly understood. Reports on the endovascular or surgical management of SCA aneurysms are rare and usually incorporated in clinical series of basilar artery or posterior circulation aneurysms. The patient was treated by delivery of a flow-diverter Pipeline Embolization Device (PED - Chestnut Medical/ev3) at the origin of vessel. She had no procedural complications and the aneurysm volume was reduced. This paper presents additional evidence to literature reports suggesting that the new endovascular flow-diverter devices are an effective and well-tolerated treatment for complex aneurysms. Our review contributes data on the incidence of recurrence as a measure of long-term efficacy of this therapeutic approach.

A rare case of intraosseous lipoma involving the sphenoclival region.

We describe the case of a 23-year-old man whose CT scan revealed a hypodense lesion reshaping the superior and middle third of the clivus and partially invading the sphenoidal sinus. MRI showed an irregular-shaped lesion occupying the body of the sphenoid bone, involving the superior and middle third of the clivus and sprouting into the sphenoid sinus. The lesion was hyperintense on T1- and T2-weighted sequences with a thin peripheral rim of hypointensity, without enhancement after i.v. gadolinium injection. The pathology report confirmed an intraosseus lipoma. Intraosseous lipomas involving the spheno-clival region are extremely rare. CT and MRI scan interpretation can be troublesome but this rare pathology has to be considered in the differential diagnosis.

Basilar artery hypoplasia.

A rare case of segmental hypoplasia of the basilar artery is described in a 49-year-old man with transient vertebrobasilar ischemia, explored by magnetic resonance imaging (MRI) and digital angiography (DA). The embryology, clinical relevance and magnetic resonance findings of this arterial anomaly are discussed, with a review of six previously reported cases. Segmental aplasia was suggested in our case by magnetic resonance, and subsequently confirmed not only by time-of-flight magnetic resonance, but also by DA. Only ultrathin-slice T2-weighted images revealed the real finding of basilar artery hypoplasia. This sequence, not employed in previously reported cases, is mandatory to allow a clear differential diagnosis between basilar artery aplasia and hypoplasia.

Sphere versus cylinder: the effect of packing on the structure of nonionic C12E6 micelles.

Two independent series of calculations are performed simulating spherical and cylindrical C12E6 micelles in a temperature range around the experimental sphere-to-rod transition temperature for surfactant concentrations less than 20% by weight. A comparative analysis of these systems helps to shed light on the microscopic details of the micelle sphere-to-rod transition. In agreement with theoretical models, we find that spherical and cylindrical micelles have a different oil core packing; the core radius of a cylindrical micelle is reduced by a factor of 0.87 with respect to the core radius of a spherical micelle. Despite this contraction, the specific volume of the alkyl tails is larger in a cylindrical micelle than in a spherical micelle. In both geometries, this specific volume follows the same linear increase with temperature. Density measurement experiments are also performed in order to evaluate the specific volume of the hydrophobic tail of surfactants of the C12Ej family with j ranging from 5 to 8. We observe a good agreement between experimental data and simulation results. Our simulations also show that the spatial distribution of the head groups in the interface is more effective in screening the oil core in the cylindrical aggregate than in the spherical aggregate, reducing by a factor of 2 the oil surface per monomer exposed to water. This screening accounts for a free-energy difference of Deltafs=fssph-fscyl approximately +2.5kBT per monomer and mirrors the essential role that the hydrophobic interactions have on the shape transition. We also find that the different interface packing correlates with different conformations and flexibility of the hydrophilic fragments E6, that appear as an entropic reservoir for the transition. Finally, comparing the degree of hydration of a spherical micelle at T=283 K with that of a cylindrical micelle at T=318 K, we observe an amount of dehydration in agreement with reported experimental data across the sphere-to-rod transition. However, for aggregates of fixed shape, we find a much smaller amount of dehydration with temperature, suggesting that the shape transition is not a consequence of the measured temperature dehydration but rather the opposite.

Pressure-induced core packing and interfacial dehydration in nonionic C12E6 micelle in aqueous solution.

A spherical micelle of C12E6 is simulated at different pressures, from 0.001 to 3 kbar, by molecular dynamics. On increasing the pressure the alkyl tails of the surfactants pack tightly and stretch. At 3 kbar we observe dynamical slowing down of the oil core of the micelle. At that pressure the core is characterized by a high oil density, rho oil approximately 0.85 g/cm(3), regular density oscillation, and low chain entropy. Pressure affects the interfacial region as well. Dehydration, induced by the collapse of the hydrophilic head groups, is observed in the inner part of the interface. Such dehydration resembles temperature dehydration but differs in details. Our results support the interpretation of recent experiments on micellar solutions at high pressure.

Dielectric behavior of lipid vesicles: the case of L-alpha-dipalmitoylphosphatidylcholine vesicles as a function of size and temperature.

We present an extensive set of radio wave dielectric relaxation spectroscopy measurements of aqueous suspensions of different size unilamellar L-alpha-dipalmitoylphosphatidylcholine (DPPC) vesicles, in a temperature range between 15 and 55 C, where the lipidic bilayer experiences structural transitions from the gel to the rippled phase (at the pretransition temperature) and from the rippled to the liquid phase (at the main transition temperature). The dielectric spectra have been analyzed in the light of the Cole-Cole relaxation function, and the main dielectric parameters-the dielectric increment Deltaepsilon and the mean relaxation frequency omega(0)--have been evaluated as a function of temperature. These parameters display a very complex phenomenology, depending on the structural arrangement of the lipid-water interface. The structural parameters that govern the dielectric behavior of these systems associated with the lipid bilayer have been recognized within a recent dynamic mean-field model we have proposed, aimed to predict the dipolar relaxation of an array of strongly interacting dipoles anchored to a flat or corrugated surface. They are the prefactor A(T) of the distance-dependent part of the effective dipolar interaction energy, the term Gamma(vis), that takes into account the damping of the dipolar motion, the average dipolar distance related to the area a(0) per polar head, and the bilayer thickness. The present analysis furnishes, from a phenomenological point of view, the dependence of these parameters on the temperature and on the vesicle size.

Shear and longitudinal viscosity of non-ionic C12E8 aqueous solutions.

We present an extensive set of measurements of steady shear viscosity (eta degrees(s)), longitudinal elastic modulus (M'), and ultrasonic absorption (alpha) in the one-phase isotropic liquid region of the non-ionic surfactant C12E8 aqueous solutions. Within a given temperature interval, this phase extends along the entire surfactant concentration range that could be fully covered in the experiments. In agreement with previous studies, the overall results support the presence of two separated intervals of concentration corresponding to different structural properties. In the surfactant-rich region the temperature dependence of eta degrees(s) follows an equation characteristic of glass-like systems. The ultrasonic absorption spectra show unambiguous evidence of viscoelastic behavior that can be described by a Cole-Cole relaxation formula. In this region, when both the absorption and the frequency are scaled by the static shear viscosity (eta degrees(s)), the scaled attenuation reduces to a single universal curve for all temperatures and concentrations. In the water-rich region the behavior of eta degrees(s), M', and alpha are more complex and reflect the presence of dispersed aggregates whose size increases with temperature and concentration. At these concentrations the ultrasonic spectra are characterized by a multiple decay rate. The high-frequency tail falls in the same frequency range seen at high surfactant content and exhibits similar behaviors. This contribution is ascribed to the mixture of hydrophilic terminations and water present at the micellar interfaces that resembles the condition of a concentrated polymer solution. An additional low-frequency contribution is also observed, which is ascribed to the exchange of water molecules and/or surfactant monomers between the aggregates and the bulk solvent region.

Small angle neutron scattering analysis of thermal stability of 23S rRNA and the intact 50S subunits of Sulfolobus solfataricus.

The ribosomes of the extremely thermophilic archaebacterium, Sulfolobus solfataricus, are very resistant to thermal denaturation (optimal growth temperature 87 degrees C), remaining essentially intact up to above 90 degrees C. However, the separate ribosomal components (rRNA and r-proteins) are less thermally stable than the ribosome as a whole, indicating that the mode of interaction of all of the components within the ribonucleoprotein particle play an essential role in determining thermal stability. To get some insight into the structural features of the thermophilic ribosome, we performed small angle neutron scattering (SANS) measurements at various temperatures on Sulfolobus solfataricus intact large ribosomal subunits (50S) and deproteinated large ribosomal subunit RNA (23S). Even if the scattering profiles suggest the presence of supramolecular aggregates in all of the samples and at all of the investigated temperatures, the measured form factors indicated for both samples that, at temperatures above 70 degrees C, the suspended particles underwent a structural rearrangement. This finding is likely to reflect single particles' properties, since S. solfataricus ribosomes are known to be biologically activated only above 60 degrees C, and there are indications that such activation requires a conformational rearrangement of the particle. A remarkable superimposition of the percentage variation of the volume from neutron scattering and of the absorbency increment with respect to temperature supports this view.

Effects of magnesium and temperature on the conformation and reassociation of Escherichia coli and Sulfolobus solfataricus ribosomes.

The structural response of the ribosomes of the extremely thermophilic archaeon Sulfolobus solfataricus was analysed and compared to that of the mesophilic (E. coli) ribosomes by assaying ethidium bromide (EB) binding to the native 70S particles as a function of magnesium concentration. We found that the thermophilic ribosomes bound more EB than their mesophilic counterparts; on the other hand, inhibition of EB binding by Mg2+ ions was more effective in the E. coli 70S particle. In Sulfolobus, the separated 30S and 50S subunits and the 70S particle bound the drug in a similar fashion, whereas the E. coli 70S had a reduced number of binding sites with respect to the subunits. Light scattering measurements as a function of Mg2+ concentration were carried out at various temperatures to study the interaction between the ribosomal subunits from the thermophilic and the mesophilic bacteria. As expected, the association of ribosomal subunits in E. coli was magnesium dependent and could be observed also at low temperature. By contrast, the interaction between Sulfolobus ribosomal subunits was obligatorily dependent upon both magnesium ions and a temperature of at least 80 degrees C, close to the physiological optimum for cell growth (87 degrees C).

Effects of magnesium ions on ribosomes: a fluorescence study.

Fluorescence intensity measurements of ethidium bromide (EB) bound to ribosomal RNA (rRNA) in suspensions of 30S and 50S subunits, of 70S ribosomal particles and of protein-free extracted rRNA are presented. Changes in the intercalation of EB reflect changes in conformation and degree of exposure of rRNA. The effect of removal of magnesium ions on the binding of EB is compared in protein-free rRNA and in ribosomal particles by a Scatchard plot analysis. In free ribosomal RNA the number of bound EBs do not depend on magnesium content, only the association constant is affected. In intact 70S particles and both in the separated 50S and 30S subunits the presence of magnesium greatly reduces binding of EB and no saturation of the fluorescence intensity with rRNA concentration is observed, preventing a Scatchard plot analysis. Removal of magnesium restores a strong EB intercalation. Then magnesium ions induce a conformational change in the 70S particles as well as in the separated subunits. The different behavior of the free-rRNA and of the ribosomal particles indicates that ribosomal proteins are relevant to the structural changes induced by magnesium ions. The comparison of the number of excluded sites and of the association constant in the 30S, 50S subunits and in the 70S particles indicates that even without Mg2+ ions the two subunits still interact, at variance with the commonly shared opinion that subunits dissociation takes place at low magnesium concentration.

Interaction of cytotoxic agents: a rule-based system for computer-assisted cell survival analysis.

The actual effectiveness of environmental noxious agents or anticancer drugs can be fully determined only by knowing if the effects (in the present case, the cytotoxic effects) induced by a given agent are enhanced by exposure to another (or other) agent(s). Given a certain combination of agents, it is possible to distinguish three types of interaction: (a) zero interaction or additivity; (b) positive interaction or synergism; and (c) negative interaction or antagonism. In this work, the methodological problems involved in evaluating the type and level of interaction between biologically active agents are discussed and an "intelligent" approach to the problem is proposed. In particular, a prototype of a computer-assisted rule based system, named CISA (Cytotoxic Interaction and Survival Analysis), designed in a KES environment (Knowledge Engineering System) and implemented on a personal computer, is described. By constructing isoboles based on experimental cell survival data and taking into account the relative confidence intervals, the system can indicate the appropriate combinations of dosages to be tested and finally determine the type and level of interaction. The system, which represents an attempt to administer "intelligently" the experimental data, is therefore able to identify the best strategy of analysis, to carry out the data processing and to offer suggestions to the investigator about the usefulness of the data and the planning of further experiments.

Effect of bleomycin on mouse haemopoietic colony forming cells in culture (CFUc).

The kinetics of CFUc studied by hydroxyurea and endotoxin treatments indicate that this cell population is proliferating actively (some 50% in S-phase). This fact implies a peculiar response to (BLM) treatment with Bleomycin, a drug which appears to be proliferation-dependent. The dose-response has a steep initial slope resulting in a low extrapolation number (n = 0.66; D37 = 960 +/- 70 mg BLM/kg body weight). The steep initial slope is confirmed by split-dose experiments resulting in a potentiation effect by fractionation. Further evidence for the dependence of the action of this drug upon the proliferative state of the cell population is derived from time-response studies after single doses of BLM.