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The possibility to excite and control charges in matter on ultrafast timescales is a key requisite to overcome the current limits of information transfer and data processing. The major route towards this milestone is based on the employment of short light pulses to manipulate the electro-optical properties of a solid. Nevertheless, the elusive physical mechanisms that unfold on extreme timescales are often complex and entangled, hindering their correct identification and possible exploitation. Here we investigate light-driven excitation in monocrystalline germanium by using attosecond transient reflection spectroscopy. We show that the complex regime established during light–matter interaction cannot be treated with simplified models but requires a detailed analysis in time and reciprocal space to address diverse phenomena such as tunnelling, band dressing, intra-band motion and multiphoton injection. Although single-photon absorption activates and develops earlier during excitation, two-photon processes, tunnelling and other field-driven phenomena reach their maximum effect soon after the peak of the pump pulse. Going against past observations, our results suggest that field-driven phenomena—namely intra-band transitions—can hinder charge injection, confirming that it is impossible to establish the next generation of petahertz information technology without a deep understanding of the diverse physical mechanism behind light–matter interaction.

To assess in a laboratory setting the ability to stay awake in a sample of workers of an Italian hospital and to investigate the association between that ability and the risk of occupational injury.

Background: Sleep disorders have been associated with increased risk of occupational injuries in various settings. Purpose: We investigated the associations between sleep, daytime sleepiness, and chronotype (preference for morning or evening activities) and the risk of occupational injuries in an Italian teaching hospital. Methods: A case-control study of employees of the University Hospital of Udine, Italy, was conducted on 200 employees reporting occupational injuries and 183 controls. Information was collected on usual sleep quantity and quality. Sleepiness was assessed with the Epworth Sleepiness Scale. Chronotype was assessed with the Horne–Ostberg morningness–eveningness questionnaire. The association of sleep-related exposures with the risk of injury was assessed with multivariate unconditional logistic regression, adjusting for potentially confounding individual characteristics. Results: Among sleep-related variables, the number of reported sleep disturbances was positively related with occupational injuries, whereas daytime sleepiness was inversely associated with injuries. Cases had shorter usual sleep hours than controls, although the difference was not statistically significant. No association was found between usual sleep hours and injuries. Chronotype was not significantly associated with injury, although we observed a decreasing trend in risk of injury from morning to evening chronotypes. Conclusions: Self-reported sleep disturbance was positively associated with increased risk of occupational injury in an Italian hospital. However, contrary to expectation, daytime sleepiness was inversely related to injuries.

Cet article a pour objet de proposer un cadre synthétique, aussi complet que possible, de la Chronica XXIV generalium ordinis Minorum. Ce texte très connu dans le contexte de l’histoire franciscaine a été largement utilisé par l’historiographie, y compris contemporaine, mais surtout considéré et étudié comme une œuvre à beaucoup d’égards originale, dans laquelle voisinent les traits de la compilation et de la chronique, inscrits dans une structure précise qui vise à ordonner un ensemble extraordinaire de matériaux hagiographiques, exemplaires, historiques et annalistiques. À partir d’un travail plus ample, publié en 2003, sur cette source riche de sens, il s’agit de présenter ici les résultats de nouvelles enquêtes plus particulières sur certains aspects thématiques importants de la Chronica. Elle est en effet devenue le miroir de la situation difficile de l’ordre à la fin du xivesiècle, à un moment où le dynamisme du siècle précédent et l’appui inconditionnel de la papauté ont laissé place à une « pause » et au grave conflit avec le chef de la chrétienté qui culmine dans les années vingt, tandis que se manifestent les tensions internes de plus en plus irrépressibles, qui mènent à la rupture et à la division.

Many patients with end stage renal disease (ESRD) undergoing dialysis therapy suffer from sleep disturbances. The aim of this study was to investigate the prevalence of sleep disorders in a large population of uraemic patients recruited from 20 different dialytic centres in Triveneto.

Our purpose was to evaluate a novel 3D Time-of-Flight (TOF) MR-Angiography (MRA) method, aimed at improving contrast resolution between vessels and static tissues.The new method consists of the acquisition of two MRA sequences, the first with the conventional technique and the second with arterial saturation. After the acquisition, digital subtraction between the two sequences was carried out to obtain a set of partitions with high flow signal and very low parenchymal signal. Five healthy volunteers and 16 patients with vascular brain diseases were studied. The resulting images were then reconstructed with maximal intensity projection (MIP) and compared with TOF MRA.In healthy volunteers subtraction-TOF showed higher contrast resolution and better visualization of small arterial vessels than the TOF technique. In the group of patients, visualization of turbulent flow lesions (i.e. aneurysms) was the same with both methods. In contrast, subtraction-TOF was superior to TOF for small vessel visualization (i.e. treated arteriovenous malformations) and for complete suppression of elevated signal intensity areas due to hematic debris (metahemoglobin).In conclusion, subtraction-TOF is a useful technique if small brain vessel visualization is required or to suppress short T1 static tissues (i.e. metahemoglobin).

A rare cerebral tumour is described with a particular enhancement pattern in post-contrast medium administration magnetic resonance images.The tumour was a supratentorial, multifocal haemangioblastoma, whose solid components did not enhance in pulse sequences acquired after contrast medium administration (double dose), but only in later acquisitions (after about 1 hour).This particular behaviour suggests using contrast medium at high doses with late acquisitions when a cerebral haemangioblastoma is suspected.