Machine learning based longitudinal virtual diagnostics at SwissFEL.

The bunch length in a linac driven Free Electron Laser (FEL) is a major parameter to be characterized to optimize the final accelerator performance. In linear machines, this observable is typically determined from the beam imaged on a screen located downstream of a Transverse Deflecting Structure (TDS) used to impinge a time dependent kick along the longitudinal coordinate of the beam. This measurement is typically performed during the machine setup and only sporadically to check the beam duration, but it cannot be continuously repeated because it is time consuming and invasive. A non-invasive method to determine the electron bunch length has already been presented in the past. This method is based on the analysis of the synchrotron radiation light spot emitted by the bunch passing through a magnetic chicane, provided that the energy chirp impinged on the bunch by the upstream radio frequency structures is known. In order to overcome a systematic discrepancy affecting the synchrotron radiation monitor based results compared to the absolute TDS based ones, we implemented and optimized a machine learning approach to predict the bunch length downstream of the two SwissFEL compression stages-from about 10 fs up to about 2 ps-as well as the beam longitudinal profile at the first one.

High-resolution ultrasound changes of the vagus nerve in idiopathic Parkinson's disease (IPD): a possible additional index of disease.

BACKGROUND AND RATIONALE: Histopathological studies revealed degeneration of the dorsal motor nucleus of the vagus nerve (VN) early in the course of idiopathic Parkinson's disease (IPD). Degeneration of VN axons should be detectable by high-resolution ultrasound (HRUS) as a thinning of the nerve trunk. In order to establish if the VN exhibits sonographic signs of atrophy in IPD, we examined patients with IPD compared with age-matched controls. MATERIAL AND METHODS: We measured the caliber (cross-sectional area, CSA) and perimeter of the VN in 20 outpatients with IPD (8 females and 12 males; mean age 73.0 + 8.6 years) and in age-matched controls using HRUS. Evaluation was performed by blinded raters using an Esaote MyLab Gamma device in conventional B-Mode with an 8-19 MHz probe. RESULTS: In both sides, the VN CSA was significantly smaller in IPD outpatients than in controls (right 2.37 + 0.91, left 1.87 + 1.35 mm2 versus 6.0 + 1.33, 5.6 + 1.26 mm2; p <0.001), as well as the perimeter (right 5.06 + 0.85, left 4.78 + 1.74 mm versus 8.87 + 0.86, 8.58 + 0.97 mm; p <0.001). There were no significant correlations between VN CSA and age, the Hoehn and Yahr scale, L-dopa therapy, and disease duration. CONCLUSION: Our findings provide evidence of atrophy of the VNs in IPD patients by HRUS. Moreover, HRUS of the VN represent a non-invasive easy imaging modality of screening in IPD patients independent of disease stage and duration and an interesting possible additional index of disease.

Generation and Characterization of Intense Ultralow-Emittance Electron Beams for Compact X-Ray Free-Electron Lasers.

The transverse emittance of the electron beam is a fundamental parameter in linac-based x-ray free-electron lasers (FELs). We present results of emittance measurements carried out at SwissFEL, a compact x-ray FEL facility at the Paul Scherrer Institute in Switzerland, including a description of the novel high-resolution measurement techniques and the optimization procedure. We obtained slice emittance values at the undulator entrance down to 200 nm for an electron beam with a charge of 200 pC and an rms duration of 30-40 fs. Furthermore, we achieved slice emittances as low as 100 nm for 10 pC beams with few fs duration. These values set new standards for electron linear accelerators. The quality, verification, and control of our electron beams allowed us to generate high-power FEL radiation for a wavelength as short as 0.1 nm using an electron beam with an energy of only 6 GeV. The emittance values demonstrated at SwissFEL would allow producing hard x-ray FEL pulses with even lower-energy beams, thus paving the way for even more compact and cost-effective FEL facilities.

Electronic eye for the prediction of parameters related to grape ripening.

An electronic eye (EE) for fast and easy evaluation of grape phenolic ripening has been developed. For this purpose, berries of different grape varieties were collected at different harvest times from veraison to maturity, then an amount of the derived must was deposited on a white sheet of absorbent paper to obtain a sort of paper chromatography. Thus, RGB images of the must spots were collected using a flatbed scanner and converted into one-dimensional signals, named colourgrams, which codify the colour properties of the images. The dataset of colourgrams was used to build calibration models to relate the colour of the images with the phenolic composition of the samples - determined by reference analytical methods - and therefore to follow the ripening trend. Satisfactory calibration models were obtained for the prediction of the most important parameters related to phenolic ripening of grapes, such as colour index, tonality, total anthocyanins content, malvidin-3-O-glucoside and petunidin-3-O-glucoside.

Epidemiology and cerebrovascular events related to cervical and intracranial arteries dissection: the experience of the city of Pisa.

Spontaneous dissection of cervical arteries (sCAD) is a major cause of ischemic stroke in young patients, with an incidence varying from 1.7 to 3/100,000/year for extracranial internal carotid artery (ICAD) and 1 to 1.9/100,000/year for extracranial vertebral artery (VAD). Reliable epidemiological data on stroke incidence related to sCAD are scarce in Italy. This study aims to evaluate the incidence, clinical features, and outcome of cerebrovascular events related to sCAD and spontaneous intracranial arteries dissections (sIAD) in the city of Pisa (Italy). We retrospectively analyzed consecutive patients admitted between December 1997 and June 2015 with a diagnosis of stroke, TIA, or Bernard-Horner syndrome due to acute cervical or intracranial artery dissection. Considering that our hospital collects presumptively all patients hospitalized with sCAD coming from the referral geographical area, data may provide a good approximation to real incidence of sCAD in our population. Clinical and radiological features, acute treatment and outcome were collected. Seventy-seven cases were included (mean age 48.1±10.4 years, range 23-77,72.7% males), 66 residents in the district of Pisa. Crude incidence rate of cerebrovascular events due to intra or extracranial dissection was 1.88/100,000/year. The incidence of ICAD was 0.80/100,000/year and 0.43/100,000/year for VAD. Stroke occurred in 76.6% of patients. VAD was more prone to cause ischemic stroke and present with cervical pain or focal signs (p < 0.01) than ICAD group, which had older age at onset. sIAD were more frequent in the posterior circle (p = 0.01) and more associated with ischemic lesions. A good outcome (mRS 0-2) was observed in 79% of patients. This is the first epidemiological attempt to investigate impact of sCAD and sIAD in Italy.

A machine learning tool for re-planning and adaptive RT: A multicenter cohort investigation.

PURPOSE: To predict patients who would benefit from adaptive radiotherapy (ART) and re-planning intervention based on machine learning from anatomical and dosimetric variations in a retrospective dataset. MATERIALS AND METHODS: 90 patients (pts) treated for head-neck cancer (H&N) formed a multicenter data-set. 41 H&N pts (45.6%) were considered for learning; 49 pts (54.4%) were used to test the tool. A homemade machine-learning classifier was developed to analyze volume and dose variations of parotid glands (PG). Using deformable image registration (DIR) and GPU, patients' conditions were analyzed automatically. Support Vector Machines (SVM) was used for time-series evaluation. "Inadequate" class identified patients that might benefit from replanning. Double-blind evaluation by two radiation oncologists (ROs) was carried out to validate day/week selected for re-planning by the classifier. RESULTS: The cohort was affected by PG mean reduction of 23.7±8.8%. During the first 3weeks, 86.7% cases show PG deformation aligned with predefined tolerance, thus not requiring re-planning. From 4th week, an increased number of pts would potentially benefit from re-planning: a mean of 58% of cases, with an inter-center variability of 8.3%, showed "inadequate" conditions. 11% of cases showed "bias" due to DIR and script failure; 6% showed "warning" output due to potential positioning issues. Comparing re-planning suggested by tool with recommended by ROs, the 4th week seems the most favorable time in 70% cases. CONCLUSIONS: SVM and decision-making tool was applied to overcome ART challenges. Pts would benefit from ART and ideal time for re-planning intervention was identified in this retrospective analysis.

Microfluidic separation of magnetic nanoparticles on an ordered array of magnetized micropillars.

Microfluidic separation of magnetic particles is based on their capture by magnetized microcollectors while the suspending fluid flows past the microcollectors inside a microchannel. Separation of nanoparticles is often challenging because of strong Brownian motion. Low capture efficiency of nanoparticles limits their applications in bioanalysis. However, at some conditions, magnetic nanoparticles may undergo field-induced aggregation that amplifies the magnetic attractive force proportionally to the aggregate volume and considerably increases nanoparticle capture efficiency. In this paper, we have demonstrated the role of such aggregation on an efficient capture of magnetic nanoparticles (about 80 nm in diameter) in a microfluidic channel equipped with a nickel micropillar array. This array was magnetized by an external uniform magnetic field, of intensity as low as 6-10 kA/m, and experiments were carried out at flow rates ranging between 0.3 and 30 µL/min. Nanoparticle capture is shown to be mostly governed by the Mason number Ma, while the dipolar coupling parameter α does not exhibit a clear effect in the studied range, 1.4 < α < 4.5. The capture efficiency Λ shows a strongly decreasing Mason number behavior, Λ∝Ma^{-1.78} within the range 32 ≤ Ma ≤ 3250. We have proposed a simple theoretical model which considers destructible nanoparticle chains and gives the scaling behavior, Λ∝Ma^{-1.7}, close to the experimental findings.

Intra-arterial tissue plasminogen activator and abciximab in patients with acute basilar artery occlusion.

Acute basilar artery occlusion has a poor prognosis and best treatment has not been assessed yet; as for intra-arterial treatment, no "gold standard" exists. We evaluated a series of ten patients treated with intra-arterial combination of recombinant tissue plasminogen activator (rtPA) and abciximab. Partial/complete recanalisation was achieved in all patients and good outcome (1 month Modified Rankin Scale 0-2) in eight cases, while one patient had symptomatic intracranial haemorrhage and died. Such outcome appears significantly better if compared with the results of Basilar Artery International Cooperation Study, suggesting that intra-arterial administration of rtPA and abciximab may be a promising option in patients with acute basilar artery occlusion undergoing endovascular treatment.

On the mechanism of charge transport in pentacene.

Terahertz transient conductivity measurements are performed on pentacene single crystals, which directly demonstrate a strong coupling of charge carriers to low frequency molecular motions with energies centered around 1.1 THz. We present evidence that the strong coupling to low frequency motions is the factor limiting the conductivity in these organic semiconductors. Our observations explain the apparent paradox of the "bandlike" temperature dependence of the conductivity beyond the validity limit of the band model.

'INDOTEST' in atypical hemicrania continua.

Hemicrania continua (HC) is an indomethacin-responsive headache characterized by a chronic, strictly unilateral, side-locked without side-shifting, persistent headache. We report three cases of HC with atypical features in which an acute administration of indomethacin 50 mg IM (INDOTEST) was performed. In all three cases INDOTEST predicted chronic responsiveness to indomethacin. Thus, in cases of HC with atypical features, INDOTEST could help for a correct diagnosis and therapy.

La magnitud del shunt derecha-izquierda no afecta al cuadro clínico de la migraña con aura: ¿qué significa / The magnitude of a right-to-left shunt does not affect the clinical features of migraine with aura: what does this mean?

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Motor unit number estimation (mune) as a quantitative measure of disease progression and motor unit reorganization in amyotrophic lateral sclerosis.

Motor Unit Number Estimation (MUNE), a technique allowing to estimate the number of functioning Motor Units (MU) in single muscles, was used to score the disease's severity and progression rate in a group of 58 patients with Amyotrophic Lateral Sclerosis (ALS). All patients underwent MUNE in the abductor digiti minimi (ADM) muscle during the diagnostic work-up (T0), after three (T1) and six (T2) months. A significant loss [p < .001] of MU and a decrease [p < .001] of the maximal M wave area at T0 was found, whereas mean step area was increased [p < .001]. During the follow-up (T1 and T2), MU loss continued, maximal M wave decreased, and mean step area increased significantly. The results confirm that MUNE is a suitable tool to quantify the pathological changes in MU in patients with ALS.

Analysis of aneusomy level and HER-2 gene copy number and their effect on amplification rate in breast cancer specimens read as 2+ in immunohistochemical analysis.

Our aim was to determine the aneusomy level and the HER-2 gene copy numbers, by fluorescence in situ hybridization (FISH) and to analyze their impact on the amplification rate in breast carcinomas considered HER-2 weakly positive cases by immunohistochemistry. We evaluated 343 breast carcinomas using double colour FISH (LSI Her-2/neu gene and CEP 17). Monosomy and polysomy were demonstrated in 24.2% and 46.1% respectively and 101/343 (29.6%) of the specimens were amplified by FISH. A statistically significant difference was observed, when we compared the amplification percentage in polysomic and monosomic specimens (P<0.0001) and, among polysomic specimens, when tumours were compared with HER-2 gene signals number per cell between 3 and 10 and >10 respectively (P<0.0001). Logistic regression analysis showed that HER-2 signals >10 and polysomy absence were independently associated with amplification. Our results confirm that the majority of 2+ IHC cases express the HER-2 protein without gene amplification and highlight the effect of chromosome 17 aneusomy and the HER-2 gene copy number on amplification.

The extent of right-to-left shunt fails to correlate with severity of clinical picture in migraine with aura.

Several investigations have documented an increased incidence of right-to-left shunt (RLS) in migraine with aura (MA) and have emphasised its role in the physiopathology of aura; so far, however, no data are available concerning a possible correlation between the extent of the RLS and the clinical picture of MA patients. To investigate the possible relationship between the extent of the RLS, revealed by the number of microbubbles (MB) detected during transcranial Doppler with IV injection of ultrasound contrast (TCDc), and the clinical characteristics of MA (age at first onset of migraine, mean annual frequency of attacks and mean duration of the aura phase), 30 consecutive patients with typical aura and migraine headache positive on TCDc evaluation for RLS were enrolled. Permanent RLS was found in 12 patients and latent RLS was found in 18 patients; of these, 6 had a high-grade RLS, 5 medium-grade RLS and 7 low-grade RLS. No correlation has been documented between the number of MBs and the clinical parameters of both patients with latent shunts and those with permanent ones, nor between the clinical parameters of the two groups of patients. These data show that RLS does not seem to affect the clinical manifestation of MA and that the extent of RLS fails to correlate with the severity of the clinical picture of the disorder.

Chromatic pattern-reversal electroretinograms (ChPERGs) are spared in multiple system atrophy compared with Parkinson's disease.

Idiopathic Parkinson's disease (IPD) patients have abnormal visual evoked potentials (VEPs) and pattern electroretinograms (PERGs), attributed to dopaminergic transmission deficiency in visual pathway, probably the retina. VEP abnormalities are not reported in multiple system atrophy (MSA). The aim of this study was to investigate and compare chromatic (Ch) red-green (R-G) and blue-yellow (B-Y), and luminance yellow-black (Y-Bk) PERGs in patients with MSA and IPD. We investigated 6 MSA patients (mean age: 62+/-7.4 years) not undergoing any pharmacological treatment, as well as 12 early IPD patients (mean age: 60.1+/-8.3 years) and 12 age-matched normal observers. ChPERGs were recorded monocularly in response to full-field equiluminant R-G, B-Y and Y-Bk horizontal gratings. In MSA only responses to R-G stimuli showed minimal insignificant changes (slight but not significant amplitude reduction without any significant latency delay); no significant abnormality was detected for B-Y and luminance Y-Bk stimuli. By contrast, in IPD all responses were reduced in amplitude and delayed in latency, above all for B-Y stimuli. Present data indicate that both chromatic and achromatic PERGs are virtually unaffected in MSA, whereas in early IPD they are clearly impaired, suggesting different pathogenic retinal mechanisms and a useful simple tool for distinguishing MSA from IPD.