Free-electron lasing with compact beam-driven plasma wakefield accelerator.

The possibility to accelerate electron beams to ultra-relativistic velocities over short distances by using plasma-based technology holds the potential for a revolution in the field of particle accelerators1-4. The compact nature of plasma-based accelerators would allow the realization of table-top machines capable of driving a free-electron laser (FEL)5, a formidable tool to investigate matter at the sub-atomic level by generating coherent light pulses with sub-ångström wavelengths and sub-femtosecond durations6,7. So far, however, the high-energy electron beams required to operate FELs had to be obtained through the use of conventional large-size radio-frequency (RF) accelerators, bound to a sizeable footprint as a result of their limited accelerating fields. Here we report the experimental evidence of FEL lasing by a compact (3-cm) particle-beam-driven plasma accelerator. The accelerated beams are completely characterized in the six-dimensional phase space and have high quality, comparable with state-of-the-art accelerators8. This allowed the observation of narrow-band amplified radiation in the infrared range with typical exponential growth of its intensity over six consecutive undulators. This proof-of-principle experiment represents a fundamental milestone in the use of plasma-based accelerators, contributing to the development of next-generation compact facilities for user-oriented applications9.

Stable Operation of a Free-Electron Laser Driven by a Plasma Accelerator.

The breakthrough provided by plasma-based accelerators enabled unprecedented accelerating fields by boosting electron beams to gigaelectronvolt energies within a few centimeters [1-4]. This, in turn, allows the realization of ultracompact light sources based on free-electron lasers (FELs) [5], as demonstrated by two pioneering experiments that reported the observation of self-amplified spontaneous emission (SASE) driven by plasma-accelerated beams [6,7]. However, the lack of stability and reproducibility due to the intrinsic nature of the SASE process (whose amplification starts from the shot noise of the electron beam) may hinder their effective implementation for user purposes. Here, we report a proof-of-principle experiment using plasma-accelerated beams to generate stable and reproducible FEL light seeded by an external laser. FEL radiation is emitted in the infrared range, showing the typical exponential growth of its energy over six consecutive undulators. Compared to SASE, the seeded FEL pulses have energies 2 orders of magnitude larger and stability that is 3 times higher.

Diagnostic accuracy of transvaginal ultrasound for detection of endometriosis using International Deep Endometriosis Analysis (IDEA) approach: prospective international pilot study.

OBJECTIVE: To evaluate the diagnostic accuracy of transvaginal ultrasound (TVS) in predicting deep endometriosis (DE) following the International Deep Endometriosis Analysis (IDEA) consensus methodology. METHODS: This was an international multicenter prospective diagnostic accuracy study involving eight centers across six countries (August 2018-November 2019). Consecutive participants with endometriosis suspected based on clinical symptoms or historical diagnosis of endometriosis were included. The index test was TVS performed preoperatively in accordance with the IDEA consensus statement. At each center, the index test was interpreted by a single sonologist. Reference standards were: (1) direct visualization of endometriosis at laparoscopy, as determined by a non-blinded surgeon with expertise in endometriosis surgery; and (2) histological assessment of biopsied/excised tissue. Surgery was performed within 12 months following the index TVS. Accuracy, sensitivity, specificity, positive and negative predictive values (PPV and NPV) and positive and negative likelihood ratios (LR+ and LR-) of TVS in the diagnosis of DE were calculated. RESULTS: Included in the study were 273 participants with complete clinical, TVS, laparoscopic and histological data. Of these, based on histology, 256 (93.8%) were confirmed to have endometriosis, including superficial endometriosis, and 190 (69.6%) were confirmed to have DE. Based on surgical visualization, 207/273 (75.8%) patients had DE. For DE overall, the diagnostic performance of TVS based on surgical visualization as the reference standard was as follows: accuracy, 86.1%; sensitivity, 88.4%; specificity, 78.8%; PPV, 92.9%; NPV, 68.4%; LR+, 4.17; LR-, 0.15, and the diagnostic performance of TVS based on histology as the reference standard was as follows: accuracy, 85.9%; sensitivity, 89.8%; specificity, 75.9%; PPV, 90.4%; NPV, 74.6%; LR+, 3.72; LR-, 0.13. CONCLUSIONS: Using the IDEA consensus methodology provides strong diagnostic accuracy for TVS assessment of DE. We found a higher TVS detection rate of DE overall than that reported by the most recent meta-analysis on the topic (sensitivity, 79%), albeit with a lower specificity. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Mortality and prognostic factors in patients with bullous pemphigoid: a retrospective multicenter Italian study.

INTRODUCTION: Bullous pemphigoid is the most common autoimmune bullous dermatosis. In recent years several studies have tried to identify the main factors of the disease related with an increased risk of death. The aim of this multicenter Italian study was to assess the risk score of death considering epidemiologic, clinical, immunological, and therapeutic factors in a cohort of patients affected by bullous pemphigoid and try to identify the cumulative survival up to 120 months. METHODS: We retrospectively reviewed the medical records of patients with bullous pemphigoid who were diagnosed between 2005 and 2020 in the 12 Italian centers. Data collected included sex, age at the time of diagnosis, laboratory findings, severity of disease, time at death/censoring, treatment, and multimorbidity. RESULTS: A total of 572 patients were included in the study. The crude mortality rate was 20.6%, with an incidence mortality rate of 5.9 × 100 person/year. The mortality rate at 1, 3, 5, and 10 years was 3.2%, 18.2%, 27.4% and 51.9%, respectively. Multivariate model results showed that the risk of death was significantly higher in patients older than 78 years, in presence of multimorbidity, anti-BP180 autoantibodies >72 U/mL, or anti-BP230 > 3 U/mL at diagnosis. The variables jointly included provided an accuracy (Harrel's Index) of 77% for predicting mortality. CONCLUSION: This study represents the first nationwide Italian study to have retrospectively investigated the mortality rates and prognostic factors in patients with bullous pemphigoid. A novel finding emerged in our study is that a risk prediction rule based on simple risk factors (age, multimorbidity, steroid-sparing drugs, prednisone use, and disease severity) jointly considered with two biomarkers routinely measured in clinical practice (anti-BP230 and anti-BP180 autoantibodies) provided about 80% accuracy for predicting mortality in large series of patients with this disease.

Reconstructing historical exposure to asbestos: the validation of 'educated guesses'.

BACKGROUND: In both the epidemiological and legal context, the causal attribution of asbestos-related lung diseases requires retrospective exposure assessment (REA). AIMS: To assess the correlation between the retrospective assessment of occupational and anthropogenic environmental exposure to asbestos and its content in the lung tissue. METHODS: Based on the available exposure information, a team of occupational physicians retrospectively assessed cumulative exposure to asbestos in 24 subjects who died of asbestos-related diseases. The asbestos lung content was analysed using analytical scanning electron microscope (SEM-EDS). The Log10 asbestos fibre count in the autoptic samples was predicted as a function of the Log10 estimated cumulative exposure using univariate regression analysis. RESULTS: The median count of asbestos fibres by grams of dry weight (ff/gdw) in the lung tissue was 81 339 (range 0-2 135 849.06); it was 287 144 (range 0-2 135 849.06) among the occupationally exposed, and 29 671 (range 0-116 891) among the subjects who only had anthropogenic environmental and/or household exposure. Amphiboles, and particularly amosite (52%) and crocidolite (43%), were detected in all the study subjects. Chrysotile was not detected in any of the samples. Overall, the retrospective estimate of lifetime cumulative exposure to asbestos showed a moderate correlation with the total asbestos fibre count in the autoptic lung, with the regression model explaining 38-55% of the total variance. CONCLUSIONS: Detailed information on occupational, environmental and household exposure circumstances would be indispensable for experienced industrial hygienists and/or occupational physicians to reliably assess past exposure to amphiboles or mixed types of asbestos.

Chloracne: a case series on cutaneous expression of CYP1A1 as diagnostic biomarker.

Chloracne, also known as metabolizing acquired dioxin-induced skin hamartomas (MADISH), is a rare disfiguring disease related to dioxin exposure. There is a paucity of literature on the clinical manifestations and pathogenesis of chloracne/MADISH. The aim of this study was to assess the clinical features of this very unusual acneiform eruption and to explore the pathogenesis of the disease. This was a retrospective, observational report study was conducted on five patients belonging to the same nuclear family (father, mother and three children) and a relative (father's brother) living in the same house. Histopathological, immunohistochemical, laboratory and toxicological analyses were performed for all patients. The results suggest that CYP1A1 in human skin is a diagnostic biomarker in chloracne, and was positive for all the patients in our sample. Tetrachlorodibenzo-p-dioxin is the most investigated dioxin responsible for chloracne; however, several other agonists, whether dioxin-like or not, can activate the aryl hydrocarbon receptor. To our knowledge, this Italian case series is the first study to suggest polychlorinated biphenyls as a possible cause of an overstimulation of aryl hydrocarbons causing the consequent acneiform eruption.

Longitudinal Phase-Space Manipulation with Beam-Driven Plasma Wakefields.

The development of compact accelerator facilities providing high-brightness beams is one of the most challenging tasks in the field of next-generation compact and cost affordable particle accelerators, to be used in many fields for industrial, medical, and research applications. The ability to shape the beam longitudinal phase space, in particular, plays a key role in achieving high-peak brightness. Here we present a new approach that allows us to tune the longitudinal phase space of a high-brightness beam by means of plasma wakefields. The electron beam passing through the plasma drives large wakefields that are used to manipulate the time-energy correlation of particles along the beam itself. We experimentally demonstrate that such a solution is highly tunable by simply adjusting the density of the plasma and can be used to imprint or remove any correlation onto the beam. This is a fundamental requirement when dealing with largely time-energy correlated beams coming from future plasma accelerators.

Focusing of High-Brightness Electron Beams with Active-Plasma Lenses.

Plasma-based technology promises a tremendous reduction in size of accelerators used for research, medical, and industrial applications, making it possible to develop tabletop machines accessible for a broader scientific community. By overcoming current limits of conventional accelerators and pushing particles to larger and larger energies, the availability of strong and tunable focusing optics is mandatory also because plasma-accelerated beams usually have large angular divergences. In this regard, active-plasma lenses represent a compact and affordable tool to generate radially symmetric magnetic fields several orders of magnitude larger than conventional quadrupoles and solenoids. However, it has been recently proved that the focusing can be highly nonlinear and induce a dramatic emittance growth. Here, we present experimental results showing how these nonlinearities can be minimized and lensing improved. These achievements represent a major breakthrough toward the miniaturization of next-generation focusing devices.

Hemodynamic changes in Chevalier eversion versus conventional carotid endarterectomy.

OBJECTIVES: The eversion carotid endartectomy (E-CEA), mainly performed by means of Vanmaele technique, has been associated with loss of the baroreceptor reflex and postoperative hypertension. The purpose of this paper is to determine whether the eversion endarterectomy performed by means of Chevalier technique (C-CEA) modifies the function and the efficiency of baroreceptors, leading to lower postoperative hemodynamic change. METHODS: A retrospective review of 380 patients who underwent carotid endarterectomy (120 Chevalier-CEA; 260 Standard-CEA) from December 2002 to November 2012 has been performed. The changes of blood pressure baseline during the postoperative course in C-CEA and S-CEA group were analysed and compared. Postoperative hypertension was defined as an elevation of systolic pressure >180 mm Hg or >40% rise above baseline. RESULTS: The patients with Chevalier eversion technique did not develop a significantly higher blood pressure in the postoperative course compared to those operated with the standard technique. In the recovery room, the mean systolic blood pressure was 134 ± 21.9 mm Hg in C-CEA group versus 132 ± 24.6 mm Hg in S-CEA group. In the first postoperative day it was 132 ± 17.2 mm Hg in C-CEA versus 133 ± 17.4 mm Hg in S-CEA group. During the first six hours in the recovery room, the need for intravenous antihypertensive drugs was similar in the two groups. Fourteen patients in C-CEA group (11%) and thirty patients (11.5%) in the S-CEA group required vasodilators, without any significant difference (p = 1). The dosage of current preoperative antihypertensive therapy was increased in six patients (4.9%) of C-CEA group and in twelve patients (4.9%) of S-CEA group, without significant difference (p = 1). CONCLUSIONS: C-CEA has the same rate of postoperative hypertension of standard-CEA, which is probably related to the sparing of baroreceptor apparatus, compared to standard E-CEA. The Chevalier procedure could represent an E-CEA technique with its inherent advantages, without penalties related to postoperative hypertension, commonly observed after E-CEA.

Diet assessment and the screening for osteoporosis: a survey in a healthy menopause population.

AIM: The aim of this study was to investigate about diet assessment in the screening for osteoporosis. METHODS: In 1,441 women (group A, mean age 53.5 years, mean time from menopause 3.92(+/-4.33)] the number of daily/weekly servings/cups of different foods has been collected. In 71 women (group B, mean age 59 years, mean time from menopause 6 years) diet was assessed through a detailed questionnaire. Demographic and clinical data and dietary habits were related to bone mineral density (BMD) values, using Student t-test and the chi2 test. RESULTS: Group A: borderline/reduced BMD 40%, the percentage increasing with age and the duration of menopause (P<0.001). BMI within normal range 56.28%. BMD values were positively associated with Body Mass Index (BMI, P<0.001), education level (P<0.005), job (P<0.01), oral contraceptives use (P<0.001), negatively with family history of osteoporosis (P<0.05). BMD values showed a positive relation with the number of eggs per week (P<0.05), positive not significant trends were observed with dairy products, vegetables, red and white meat intake. A low/reduced BMD was related to low calcium food intake in less than 50% of the women. Group B: borderline/reduced BMD 55%; BMD showed positive trends, not significant, with daily calcium intake, BMI, physical exercise. Estimated calcium intake less than 700 mg/day was found in 33% of the sample. CONCLUSION: Diet assessment is not useful in the screening for osteoporosis. In women with borderline or reduced BMD, diet assessment helps to detect those at low calcium intake who need calcium supplementation, alone or in combination with other treatments.