Accuracy and precision of the RABBIT technique.

One of the most ubiquitous techniques within attosecond science is the so-called reconstruction of attosecond beating by interference of two-photon transitions (RABBIT). Originally proposed for the characterization of attosecond pulses, it has been successfully applied to the accurate determination of time delays in photoemission. Here, we examine in detail, using numerical simulations, the effect of the spatial and temporal properties of the light fields and of the experimental procedure on the accuracy of the method. This allows us to identify the necessary conditions to achieve the best temporal precision in RABBIT measurements. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.

Time-Stretched Spectroscopy by the Quantum Zeno Effect: The Case of Auger Decay.

A tenet of time-resolved spectroscopy is "faster laser pulses for shorter timescales". Here, we suggest turning this paradigm around, and slowing down the system dynamics via repeated measurements, to do spectroscopy on longer timescales. This is the principle of the quantum Zeno effect. We exemplify our approach with the Auger process, and find that repeated measurements increase the core-hole lifetime, redistribute the kinetic energy of Auger electrons, and alter entanglement formation. We further provide an explicit experimental protocol for atomic Li, to make our proposal concrete.

Attosecond pulse walk-off in high-order harmonic generation.

We study the influence of the generation conditions on the group delay of attosecond pulses in high-order harmonic generation in gases. The group delay relative to the fundamental field is found to decrease with increasing gas pressure in the generation cell, reflecting a temporal walk-off due to the dispersive properties of the nonlinear medium. This effect is well reproduced using an on-axis phase-matching model of high-order harmonic generation in an absorbing gas.

Probing time-dependent molecular dipoles on the attosecond time scale.

Photoinduced molecular processes start with the interaction of the instantaneous electric field of the incident light with the electronic degrees of freedom. This early attosecond electronic motion impacts the fate of the photoinduced reactions. We report the first observation of attosecond time scale electron dynamics in a series of small- and medium-sized neutral molecules (N(2), CO(2), and C(2)H(4)), monitoring time-dependent variations of the parent molecular ion yield in the ionization by an attosecond pulse, and thereby probing the time-dependent dipole induced by a moderately strong near-infrared laser field. This approach can be generalized to other molecular species and may be regarded as a first example of molecular attosecond Stark spectroscopy.

Isotope effects in dynamics of water isotopologues induced by core ionization at an x-ray free-electron laser.

Dynamical response of water exposed to x-rays is of utmost importance in a wealth of science areas. We exposed isolated water isotopologues to short x-ray pulses from a free-electron laser and detected momenta of all produced ions in coincidence. By combining experimental results and theoretical modeling, we identify significant structural dynamics with characteristic isotope effects in H2O2+, D2O2+, and HDO2+, such as asymmetric bond elongation and bond-angle opening, leading to two-body or three-body fragmentation on a timescale of a few femtoseconds. A method to disentangle the sequences of events taking place upon the consecutive absorption of two x-ray photons is described. The obtained deep look into structural properties and dynamics of dissociating water isotopologues provides essential insights into the underlying mechanisms.

Role of the Renner-Teller effect after core hole excitation in the dissociation dynamics of carbon dioxide dication.

The fragmentation of the doubly-charged carbon dioxide molecule is studied after photoexcitation to the C 1s(1)2π(u) and O 1s(1)2π(u) states using a multicoincidence ion-imaging technique. The bent component of the Renner-Teller split states populated in the 1s→ π* resonant excitation at both the carbon and oxygen 1s ionization edges opens pathways to potential surfaces in highly bent geometries in the dication. Evidence for a complete deformation of the molecule is found in the coincident detection of C(+) and O(2)(+) ions. The distinct alignment of this fragmentation channel indicates rapid deformation and subsequent fragmentation. Investigation of the complete atomization dynamics in the dication leading to asymmetric charge separation shows that the primary dissociation mechanisms, sequential, concerted, and asynchronous concerted, are correlated to specific fragment kinetic energies. The study shows that the bond angle in fragmentation can extend below 20°.

What the specific tools of geriatrics and oncology can tell us about the role and status of geriatricians in a pilot geriatric oncology program.

BACKGROUND: Pilot Oncogeriatric Coordination Units (UPCOGs) were created by the French National Cancer Institute (INCA) in order to implement routine geriatric assessment of all cancer patients over 75 years of age. This article examines the role of geriatric and oncologic tools in the organization of medical oncogeriatric activities, focusing on the role and place of geriatricians. METHODS: We conducted a qualitative sociological survey in the West Paris Oncogeriatric Program (POGOP), one of the Pilot Oncogeriatric Coordination Units (UPCOGs) recently created in France. Various qualitative methods were used including a review of the literature, participative observational surveys, and semidirective interviews with medical staff managing elderly cancer patients. RESULTS: The results show that the way in which geriatric assessment procedures are implemented confirms the role of the geriatrician in the diagnosis and prevention of vulnerabilities and fragility at the time of initial diagnosis and medical decision making. Nevertheless, the articulation of these different working methods gives rise to various organizational configurations. CONCLUSIONS: The POGOP has largely contributed to clarifying medical activity in oncogeriatrics: identification of physicians, definition of shared goals, initiation, and structuring of new partnerships. Nevertheless, the geriatrician's tools, expertise, and know-how are often perceived ambiguously.

Probing single-photon ionization on the attosecond time scale.

We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. We measure the difference in time delays between electrons emitted from the 3s(2) and from the 3p(6) shell, at different excitation energies ranging from 32 to 42 eV. The determination of photoemission time delays requires taking into account the measurement process, involving the interaction with a probing infrared field. This contribution can be estimated using a universal formula and is found to account for a substantial fraction of the measured delay.

Phase measurement of resonant two-photon ionization in helium.

We study resonant two-color two-photon ionization of helium via the 1s3p (1)P(1) state. The first color is the 15th harmonic of a tunable Ti:sapphire laser, while the second color is the fundamental laser radiation. Our method uses phase-locked high-order harmonics to determine the phase of the two-photon process by interferometry. The measurement of the two-photon ionization phase variation as a function of detuning from the resonance and intensity of the dressing field allows us to determine the intensity dependence of the transition energy.

Nuclear motion in carbonyl sulfide induced by resonant core electron excitation.

The angular anisotropy for selected dissociation channels is measured at resonantly excited states of Σ and Π symmetries at the C and O K-shell ionization edges of carbonyl sulfide. While the kinetic energy released in the reaction is mainly independent of the excitation energy, the angular anisotropy and momentum correlation clearly show deformation of the OCS molecule in the C 1s(-1)π(∗1) state. The discovery of a two-body fragmentation channel SO(+)/C(+) with a well defined angular anisotropy indicates the rapid formation of the CSO isomeric species.

Attosecond timing of electron emission from a molecular shape resonance.

Shape resonances in physics and chemistry arise from the spatial confinement of a particle by a potential barrier. In molecular photoionization, these barriers prevent the electron from escaping instantaneously, so that nuclei may move and modify the potential, thereby affecting the ionization process. By using an attosecond two-color interferometric approach in combination with high spectral resolution, we have captured the changes induced by the nuclear motion on the centrifugal barrier that sustains the well-known shape resonance in valence-ionized N2. We show that despite the nuclear motion altering the bond length by only 2%, which leads to tiny changes in the potential barrier, the corresponding change in the ionization time can be as large as 200 attoseconds. This result poses limits to the concept of instantaneous electronic transitions in molecules, which is at the basis of the Franck-Condon principle of molecular spectroscopy.

Dynamics of proton migration and dissociation in core-excited ethyne probed by multiple ion momentum imaging.

The study focuses on the rapid geometry change in ethyne excited near the carbon 1s edge. Core excitation and ionization lead to population of dicationic states in ethyne. We study three competing dissociation pathways associated with deprotonation in the linear ethyne molecule, and two cases of rapid proton migration. We investigate the alignment of the molecule in the excited state and find startling differences in these three cases. We present evidence for a strong anisotropy in the production of H(2)(+)/C(2)(+) fragments through a rapid deformation of the molecule to a dibridged conformation with the transition dipole moment parallel to the polarization of the exciting radiation.

[Haematological malignancies in older adults: experience in a geriatric acute care department]. / Hémopathies et sujets âgés: expérience d'un service de court séjour gériatrique.

BACKGROUND: Ageing of population due to improvement in life expectancy has increased blood diseases (BD) incidence in the elderly population. In addition, treatments get more and more complex with increasingly late diagnosis as well as concomitant comorbidities. METHODS: We describe a series of 54 patients with BD, followed-up in an acute care geriatric department. Autonomy, way of life, nutritional status, comorbidities, treatment, mortality and evolution were analyzed. RESULTS: Mean age at BD was 86+/-6 years (range 75-99) for 29 women and 25 men. Median follow up was 20 months (0-60). Lymphoma was the most frequent BD (44%). Thirty-one patients (57%) received chemotherapy. Mortality rate was 41% (22 patients). Forty patients (74%) were discharged and 25 patients (46%) required enhanced professional assistance. Survival was significantly decreased in patients with albuminemia less than or equal to 30 g/l. IADL score less than or equal to 3, ADL score less than or equal to 5, performance status more than or equal to 2, MMS less than 25 and weight loss more than or equal to 3 kg. After multivariate analysis, only albuminemia less than or equal to 30 g/l tended to predict death (hazard ratio 3.57, 95% confidence interval 0.96-13.3, p=0.06). CONCLUSION: Our study confirms the importance of nutritional status on survival. A global geriatric evaluation is required for appropriate treatment, as currently available therapeutic protocols are not really adapted for old population. Additional studies should be conducted in this direction.

[Blood management in geriatric hospitalized population]. / Épargne transfusionnelle dans la population âgée hospitalisée.

INTRODUCTION: In France, nearly 50% of patients transfused in packed red blood cells are 75 or older. The benefit of restrictive transfusion policies is no longer to be demonstrated, but the practices are still far from it. The objective of our study was to show the impact of a decision support tool on transfusion practices, specifically in a hospitalized elderly population. METHOD: A clinical decision support, validated in the improvement of practices, was created, based on the latest transfusion recommendations of 2014. Our study was interventional, monocentric, within the departments of internal medicine and geriatrics of a university hospital from February to July 2016. The clinical decision support was available for any request of transfusion of packed red blood cells for 75 years old or older patient who was hospitalized in one of these two services. RESULTS: There were 134 transfusions out of 173 for which the prescriber used our tool. Comparing 2016 with the previous two years, our tool decreased the rate of packed red blood cells delivered by 11% compared to 2014 (P<0.005), but there was no significant difference compared to 2015. It has also reduced the transfusion rate of multi-unit transfusions by 35% compared with 2014 and by 29% compared with 2015 (P<0.005). CONCLUSION: Our tool, applied specifically to the elderly, is useful to improve transfusion practices and requires to be validated on a larger scale.

Photoionization in the time and frequency domain.

Ultrafast processes in matter, such as the electron emission after light absorption, can now be studied using ultrashort light pulses of attosecond duration (10-18 seconds) in the extreme ultraviolet spectral range. The lack of spectral resolution due to the use of short light pulses has raised issues in the interpretation of the experimental results and the comparison with theoretical calculations. We determine photoionization time delays in neon atoms over a 40-electron volt energy range with an interferometric technique combining high temporal and spectral resolution. We spectrally disentangle direct ionization from ionization with shake-up, in which a second electron is left in an excited state, and obtain excellent agreement with theoretical calculations, thereby solving a puzzle raised by 7-year-old measurements.

[Acute megakaryoblastic leukemia (AML-7) in a woman of 95 years]. / Leucémie aiguë mégacaryoblastique (LAM-7) chez une patiente de 95 ans.

Acute leukemia of megakaryocyte lineage (AML-7) is a rare entity defined by a blastic proliferation of which a part (>or= 50%) is represented by megakaryoblasts. We report the case of a 95 year old woman presenting a AML-7 secondary to a myelodysplastic syndrome (MDS), that represents an unusual form of MDS acutisation.

Spectral phase measurement of a Fano resonance using tunable attosecond pulses.

Electron dynamics induced by resonant absorption of light is of fundamental importance in nature and has been the subject of countless studies in many scientific areas. Above the ionization threshold of atomic or molecular systems, the presence of discrete states leads to autoionization, which is an interference between two quantum paths: direct ionization and excitation of the discrete state coupled to the continuum. Traditionally studied with synchrotron radiation, the probability for autoionization exhibits a universal Fano intensity profile as a function of excitation energy. However, without additional phase information, the full temporal dynamics cannot be recovered. Here we use tunable attosecond pulses combined with weak infrared radiation in an interferometric setup to measure not only the intensity but also the phase variation of the photoionization amplitude across an autoionization resonance in argon. The phase variation can be used as a fingerprint of the interactions between the discrete state and the ionization continua, indicating a new route towards monitoring electron correlations in time.

[Radiation therapy for elderly patients]. / Quelles sont les spécificités de la prise en charge d'une personne âgée en radiothérapie ?

Cancer is a disease that predominantly occurs in older patients who represent a quarter of the population in western countries. Numerous types of cancer are observed in elderly people. Radiotherapy is one of the most powerful treatments against cancer. Most of published studies have demonstrated feasibility of radiotherapy in curative or palliative intent whatever cancer types are considered. Complete geriatric assessment and a multidisciplinary approach are the key points. The purpose of this review is to highlight sights of radiation oncology specifically related to aging. Particular emphasis is placed on logistic and technical aspects of radiation, as dose, irradiated volume, fractionation and the potential usefulness of new technologies.

Incidence and predictors of major hemorrhagic complications from thrombolytic therapy in patients with massive pulmonary embolism.

PURPOSE: The risk factors for bleeding in patients receiving recombinant tissue-type plasminogen activator for massive pulmonary embolism are not known. PATIENTS AND METHODS: The hospital records of 132 consecutive patients who received recombinant tissue-type plasminogen activator for massive pulmonary embolism were retrospectively reviewed. Bleeding was estimated by using the bleeding severity index, a method previously validated in patients receiving anticoagulants. Multivariate stepwise logistic regression was used to identify independent risk factors for bleeding. Four other definitions of bleeding in large pulmonary embolism thrombolytic trials were also used, and the agreement among these criteria was assessed. RESULTS: According to the bleeding severity index, 33 patients (25%) had one or more major bleeding complications. Hemorrhage at the venous puncture site for angiography was the most frequent complication (15 patients, 11%). Major bleeding at the catheterization site was more common at the femoral site (14 of 63 patients = 22%) than at the brachial site (1 of 63 patients = 2%; P = 0.0004). The use of the five different bleeding definitions resulted in a variation in the major bleeding rate from 3% to 43%. The kappa coefficient varied from 0.07 to 0.84, indicating poor agreement between most of the classifications. CONCLUSION: The use of the femoral vein for pulmonary angiography was the only variable significantly associated with major bleeding. Most of the differences observed in the pulmonary embolism thrombolytic trials are likely related to the differences in the definition of bleeding rather than to the thrombolytic regimen.

Clinical presentation and results of thrombolytic therapy in older patients with massive pulmonary embolism: a comparison with non-elderly patients.

OBJECTIVE: To assess the clinical presentation and effectiveness of thrombolytic therapy in older patients suffering from massive pulmonary embolism. DESIGN: Analysis of a previously reported study of patients with massive pulmonary embolism using a dichotomous classification of age. SETTING: A medical intensive care unit in one hospital center. PARTICIPANTS: All subjects had massive pulmonary embolism as evidenced by scintigraphic and/or angiographic assessment. The 54 patients included in this study were divided into two groups according to age: 28 patients were less than 75 years old and 26 patients were 75 years old or older. INTERVENTION: All patients received a bolus regimen of single-chain recombinant tissue-type plasminogen and were subsequently treated by heparin and warfarin. MEASUREMENTS: Clinical symptoms at admission, resolution of scintigraphic vascular obstruction, death rate, hemorrhagic complications, recurrent pulmonary embolism, and long-term follow-up were compared between both groups. RESULTS: Clinical symptoms at admission were similar in both groups. The mean absolute improvement in the lung scan perfusion defect, the rate of major bleeding, and the long-term evolution were not statistically different between older and younger patients. CONCLUSION: Clinical symptoms, including hemodynamic condition, did not differ between elderly and nonelderly patients suffering from massive pulmonary embolism. Old age should not preclude thrombolytic therapy in massive pulmonary embolism, provided there is no other contraindication for thrombolytic treatment.