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.

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 accelerators^1-4. 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 durations^6,7. 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.

Time-resolved study of nonlinear photoemission in radio-frequency photoinjectors

Photoemission is one of the fundamental processes that describes the generation of charged particles from materials irradiated by photons. The continuous progress in the development of ultrashort lasers allows investigation into the dynamics of the process at the femtosecond timescale. Here we report about experimental measurements using two ultrashort ultraviolet laser pulses to temporally probe the electrons release from a copper cathode in a radio-frequency photoinjector. By changing their relative delay, we studied how the release mechanism is affected by two-photon photoemission when tens of GW/cm² intensities are employed. We evaluated the limits it poses on the achievable beam brightness and analyzed the resulting emission yield in terms of the electronic temperature by modeling the cathode as a two-temperature system.

Ultrafast electron and proton bunches correlation in laser-solid matter experiments

The interaction of an ultra-intense laser with a solid state target allows the production of multi-MeV proton and ion beams. This process is explained by the target normal sheath acceleration (TNSA) model, predicting the creation of an electric field on the target rear side, due to an unbalanced positive charge. This process is related to the emission of relativistic ultrafast electrons, occurring at an earlier time. In this work, we highlight the correlations between the ultrafast electron component and the protons by their simultaneous detection by means of an electro-optical sampling and a time-of-flight diagnostics, respectively, supported by numerical simulations showing an excellent agreement.

Time-resolved characterization of ultrafast electrons in intense laser and metallic-dielectric target interaction

High-intensity ultrashort laser pulses interacting with thin solid targets are able to produce energetic ion beams by means of extremely large accelerating fields set by the energetic ejected electrons. The characterization of such electrons is thus important in view of a complete understanding of the acceleration process. Here, we present a complete temporal-resolved characterization of the fastest escaping hot electron component for different target materials and thicknesses, using temporal diagnostics based on electro-optical sampling with 100 fs temporal resolution. Experimental evidence of scaling laws for ultrafast electron beam parameters have been retrieved with respect to the impinging laser energy (0.4-4 J range) and to the target material, and an empirical law determining the beam parameters as a function of the target thickness is presented.

Awake laparotomy: is locoregional anesthesia a functional option for major abdominal surgeries in the COVID-19 era?

OBJECTIVE

Over the ongoing pandemic of coronavirus disease 2019 (COVID-19), the demand for critical care beds among medical services has rapidly exceeded its supply. Elective surgery has comprehensively been drastically limited and allocating intensive care beds to emergency cases or to high risk scheduled elective cases has become an even more difficult task. Here we present our experience which could help to handle undelayable surgical procedures during this emergency.

PATIENTS AND METHODS

In 2019, eight patients (4 men, 4 women) with a mean age of 88 years, needing emergency abdominal surgery underwent awake open surgery at our Department of Surgery. All of them were identified as fragile patients at preoperative evaluation by the anesthesiologist. In all cases, locoregional anesthesia (spinal, epidural or combined spinal-epidural anesthesia) was performed. Intraoperative and postoperative pain has been monitored and regularly assessed.

RESULTS

None of the patients was intubated. Mean operative time was 80 minutes (minimum 30 minutes, maximum 130 minutes). Intraoperative and postoperative pain were both well controlled. None of them required postoperative intensive care support. No perioperative complications were observed.

CONCLUSIONS

Based on our preliminary case series, awake open surgery has resulted feasible and safe. This approach has allowed to perform undelayable major abdominal surgeries on fragile patients when intensive care beds were not available. Surely, it represents a helpful alternative in the COVID-19 era. A streamlining of workflows would fast-track both fragile patients management, as well as healthcare workers' tasks and activity.

Heavy metal bioaccumulation in honey bee matrix, an indicator to assess the contamination level in terrestrial environments

The most significant risk factor for organisms living in an environment contaminated by heavy metals is the metal bioavailability. Therefore, an efficient ecotoxicological approach to metal contamination is the measure of bioaccumulation level in target organisms. In this work, we characterized the heavy metal bioaccumulation in honey bees, Apis mellifera ligustica, collected at 35 sites from Umbria (Central Italy). The comparison of our data with selected Italian investigations revealed metal bioaccumulation in honey bee matrix of the same order of magnitude, with Cd showing a higher variability. To generalize the results, we developed a Honeybee Contamination Index (HCI) based on metal bioaccumulation in honey bees. An application of the HCI to the present dataset revealed cases of low (sixteen sites), intermediate (eighteen sites), and high (one site) metal contaminations. The comparison of HCI values from the Umbrian dataset with values calculated for other Italian and European metadata showed that most of the Umbrian sites fell in the portion of low and intermediate contamination conditions. HCI represented a reliable tool that provided a piece of concise information on metal contamination in terrestrial environments. Parallel to this effort, we have determined, the metal concentrations in the airborne particulate matter (PM₁₀) at three regional background-monitoring stations in Umbria. These stations are representative of the average air quality of the areas of the investigated apiaries. A comparative analysis of metal enrichment factors in PM₁₀, and honey bees suggested that the contamination in the bees was related to the PM₁₀ values only to a minor extent. On the other side, a clear enrichment of metals such as Cd, Mn, Zn, and Cu in the honey bees appeared to depend on very local conditions and was probably related to the use of pesticides and fertilizers, and the resuspension of the locally contaminated soils and agriculture residues.

Time-resolved thermally induced aberrations in a flash-lamp pumped Nd:Glass disk amplifier using a 2 × 2 position sensitive detector array

A novel technique of measuring the prompt, thermally induced wave-front aberrations in a large aperture flash-lamp pumped Nd³⁺ glass disk amplifier is presented. Implementing a 2 × 2 lens array and a 2 × 2 position sensitive detector array as a diagnostic system, the wave-front profile was successfully reconstructed for the first five Zernike terms for a temporal window of 8.5 ms.

An Italian observational study on subclinical cardiovascular risk factors and depressive symptomatology. A suggestion for the potential utility of a sinergic cardio-psychiatric perspective

Introduction

Growing evidence has been collected over the complex, intertwined pathophysiological connection among subclinical cardiovascular (CV) disease, i.e. atherosclerosis, systemic low pro-inflammatory states and psychiatric disorders/symptomatology (anxiety, depression), with controversial results.

Aim

Aim of this study was to investigate the possible link between subclinical CV risk factors (atherosclerosis), depressive symptoms, and inflammation.

Methods

Cross-sectional study. Inclusion criteria: outpatients aged ≥40 years, attending colonoscopy after positive faecal occult blood test, negative medical history for cancer. Collected data: blood pressure, glycaemia, lipid profile, waist circumference, BMI, PCR (C reactive protein), LPS (bacterial lipopolysaccharide), ultrasound carotid intima-media thickness (c-IMT). Psychometric tests: HADS, TCI, IMSA, SF36. Statistical analysis performed with STATA13.

Results

The 54 patients enrolled were equally distributed by gender. CV risk factors were common in the study population, with 33 patients (61.11%) with hypertension, 14 (25.93%) with hyperglycaemia, 20 (37.4%) with hypertriglyceridemia, 19 (35.19%) with low HDL and 64.81% with overweight. High levels of PCR were found in 24 subjects (44.44%). Right c-IMT was increased in 26.41% of the sample, and 11.32% had an atheromatous plaque. Left c-IMT was increased in 24.53% of patients, with a plaque in 7.55% of them. Clinically relevant depressive symptoms were found in the 18.87% of the sample and were statistically significantly associated with PCR (OR = 28.63; P = 0.01).

Conclusions

Evidence contributing to the so-called “inflammation theory” of depression and supporting the association between mood and CV disorders was here collected, supporting the need for a multidisciplinary approach to the diagnosis and treatment of such conditions, assuming a clinically-translated PNEI (psycho-neuro-endocrino-immunological) perspective.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Cardiovascular risk factors, anxiety symptoms and inflammation markers: Evidence of association from a cross-sectional study

Introduction

Anxiety disorders and Cardiovascular (CV) diseases, among the most common disorders in Western World, are often comorbid. A chronic systemic inflammatory state might be a shared underlining pathophysiological mechanism.

Aims

To investigate the association between anxiety symptoms, CV risks factors and inflammatory markers in an outpatient sample.

Methods

Cross-sectional study. Inclusion criteria: outpatients aged ≥40 years, attending colonoscopy after positive faecal occult blood test, negative medical history for cancer. Collected data: blood pressure, glycaemia, lipid profile, waist circumference, BMI, PCR (C Reactive Protein), LPS (bacterial Lipopolysaccharide). Psychometric tests: HADS, TCI, IMSA, SF36. Statistical analysis performed with STATA13.

Results

Fifty four patients enrolled (27 males, 27 females). Sixteen patients (30.19%) were positive for anxiety symptoms. Thirty-three patients (61.11%) had hypertension, 14 (25.93%) hyperglycaemia and 64.81% were overweight, with frank obesity (BMI≥ 30) in 11 subjects (20.37%). Anxiety symptoms were associated with low hematic HDL values (OR = 0.01; P = 0.01) and high concentration of triglycerides (OR = 0.023; P = 0.02) at the multiple regression model. At the univariate logistic analysis, anxiety was associated with LPS (OR = 1.06; P = 0.04).

Conclusions

Further evidence over the epidemiological link between common mental disorders and CV diseases was collected, with possible hints on pathophysiology and causative mechanisms related to inflammation. The importance of screening for anxiety and depression in medical populations is confirmed. Suggestions on future availability of screening tools based on inflammatory-related indicators should be the focus of future research.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Sub-picosecond snapshots of fast electrons from high intensity laser-matter interactions

The interaction of a high-intensity short-pulse laser with thin solid targets produces electron jets that escape the target and positively charge it, leading to the formation of the electrostatic potential that in turn governs the ion acceleration. The typical timescale of such phenomena is on the sub-picosecond level. Here we show, for the first time, temporally-resolved measurements of the first released electrons that escaped from the target, so-called fast electrons. Their total charge, energy and temporal profile are provided by means of a diagnostics based on Electro-Optical Sampling with temporal resolution below 100 fs.

Femtosecond dynamics of energetic electrons in high intensity laser-matter interactions

Highly energetic electrons are generated at the early phases of the interaction of short-pulse high-intensity lasers with solid targets. These escaping particles are identified as the essential core of picosecond-scale phenomena such as laser-based acceleration, surface manipulation, generation of intense magnetic fields and electromagnetic pulses. Increasing the number of the escaping electrons facilitate the late time processes in all cases. Up to now only indirect evidences of these important forerunners have been recorded, thus no detailed study of the governing mechanisms was possible. Here we report, for the first time, direct time-dependent measurements of energetic electrons ejected from solid targets by the interaction with a short-pulse high-intensity laser. We measured electron bunches up to 7 nanocoulombs charge, picosecond duration and 12 megaelectronvolts energy. Our ’snapshots’ capture their evolution with an unprecedented temporal resolution, demonstrat- ing a significant boost in charge and energy of escaping electrons when increasing the geometrical target curvature. These results pave the way toward significant improvement in laser acceleration of ions using shaped targets allowing the future development of small scale laser-ion accelerators.

Thyroid hormone autoantibodies: are they a better marker to detect early thyroid damage in patients with hematologic cancers receiving tyrosine kinase inhibitor or immunoregulatory drug treatments?

BACKGROUND

Unlike cytotoxic agents, novel antineoplastic drugs can variably affect thyroid function and so impair patient outcomes. However, the widely used standard thyroid tests have demonstrated low sensitivity for detecting early thyroid damage that leads to dysfunction of the gland. To find a more reliable thyroid marker, we assessed the presence of antibodies binding thyroid hormones (thAbs) in a cancer population undergoing potentially thyrotoxic treatment.

METHODS

From April 2010 to September 2013, 82 patients with hematologic malignancies treated with tyrosine kinase inhibitors or immunoregulatory drugs were recruited. Healthy volunteers (n = 104) served as control subjects. Thyroid function, autoimmunity tests, thAbs, and thyroid sonography were assessed once during treatment.

RESULTS

Overall, thAb positivity was recorded in 13% of the entire cohort. In most cases, the thAbs were of a single type, with a predominance of T3 immunoglobulin G. More specifically, thAbs were detected in 11 cancer patients; and abnormal levels of thyroid-stimulating hormone, thyroglobulin antibody, and thyroperoxidase antibody were detected in 6 (p = 0.05), 0 (p = 0.0006), and 2 cancer patients (p = 0.001) respectively. Ultrasonographic alterations of the thyroid were observed in 12 cancer patients. In contrast, of the 104 healthy control subjects, only 1 was positive for thAbs (1%).

CONCLUSIONS

We have demonstrated for the first time that thAbs are a reliable marker of early thyroid dysfunction when compared with the widely used standard thyroid tests. A confirmatory prospective trial aiming at evaluating thAbs at various time points during treatment could clarify the incidence and timing of antibody appearance.

Collagen-gelatin-genipin-hydroxyapatite composite scaffolds colonized by human primary osteoblasts are suitable for bone tissue engineering applications: in vitro evidences

The application of porous hydroxyapatite (HAp)-collagen as a bone tissue engineering scaffold represents a new trend of mimicking the specific bone extracellular matrix (ECM). The use of HAp in reconstructive surgery has shown that it is slowly invaded by host tissue. Therefore, implant compatibility may be augmented by seeding cells before implantation. Human primary osteoblasts were seeded onto innovative collagen-gelatin-genipin (GP)-HAp scaffolds containing respectively 10%, 20%, and 30% HAp. Cellular adhesion, proliferation, alkaline phosphatase (ALP) activity, osteopontin (OPN), and osteocalcin (OC) expressions were evaluated after 3, 7, 15, and 21 days. The three types of scaffolds showed increased cellular proliferation over time in culture (maximum at 21 days) but the highest was recorded in 10% HAp scaffolds. ALP activity was the highest in 10% HAp scaffolds in all the times of evaluation. OC and OPN resulted in higher concentration in 10% HAp scaffolds compared to 20% and 30% HAp (maximum at 21 days). Finally, scanning electron microscopy analysis showed progressive scaffolds adhesion and colonization from the surface to the inside from day 3 to day 21. In vitro attachment, proliferation, and colonization of human primary osteoblasts on collagen-GP-HAp scaffolds with different percentages of HAp (10%, 20%, and 30%) all increased over time in culture, but comparing different percentages of HAp, they seem to increase with decreasing of HAp component. Therefore, the mechanical properties (such as the stiffness due to the HAp%) coupled with a good biomimetic component (collagen) are the parameters to set up in composite scaffolds design for bone tissue engineering.

Serum hepatocyte growth factor is increased in Hashimoto's thyroiditis whether or not it is associated with nodular goiter as compared with healthy non-goitrous individuals

BACKGROUND

Some growth factors and cytokines are known to cooperate with TSH in thyroid nodular growth, but few data are available on their circulating levels in Hashimoto's thyroiditis (HT).

AIM

To evaluate in HT patients whether thyroid nodules are associated with variations in serum levels of hepatocyte growth factor (HGF) and interleukin-6 (IL-6).

SUBJECTS AND METHODS

Serum levels of HGF and IL-6 were measured by enzyme-linked immunosorbent assay in 176 euthyroid subjects, subdivided into 4 groups: A) HT patients with nodular goiter (no.=42); B) non-goitrous HT patients (no.=36); C) non-HT patients with nodular goiter (no.=48), and D) healthy subjects without thyroid disease (no.=50).

RESULTS

The highest concentrations of serumHGF were found in patients with nodular goiter, irrespective of the presence of associated HT (groups A and C). Nevertheless, in group A serum HGF levels were significantly higher than in group C (860.8+/-333.6 pg/ml vs 691.5+/-156 pg/ml, p<0.01). Moreover, though serum HGF levels in group B (578.3+/-217 pg/ml) were lower than in group A, they were significantly higher than in healthy controls (group D, 512.7+/-170.4 pg/ml, p<0.001). Serum IL-6 levels were similar in the two HT groups (A and B), and increased with respect to groups C and D.

CONCLUSIONS

Serum HGF is increased in HT, especially associated to thyroid nodules, as compared with healthy non-goitrous individuals.

Quality in emergency departments: a study on 3,285,440 admissions

INTRODUCTION

A multi-centre study has been conducted, during 2005, by means of a questionnaire posted on the Italian Society of Emergency Medicine (SIMEU) web page. Our intention was to carry out an organisational and functional analysis of Italian Emergency Departments (ED) in order to pick out some macro-indicators of the activities performed. Participation was good, in that 69 ED (3,285,440 admissions to emergency services) responded to the questionnaire.

METHODS

The study was based on 18 questions: 3 regarding the personnel of the ED, 2 regarding organisational and functional aspects, 5 on the activity of the ED, 7 on triage and 1 on the assessment of the quality perceived by the users of the ED.

RESULTS AND CONCLUSION

The replies revealed that 91.30% of the ED were equipped with data-processing software, which, in 96.83% of cases, tracked the entire itinerary of the patient. About 48,000 patients/year used the ED: 76.72% were discharged and 18.31% were hospitalised. Observation Units were active in 81.16% of the ED examined. Triage programmes were in place in 92.75% of ED: in 75.81% of these, triage was performed throughout the entire itinerary of the patient; in 16.13% it was performed only symptom-based, and in 8.06% only on-call. Of the patients arriving at the ED, 24.19% were assigned a non-urgent triage code, 60.01% a urgent code, 14.30% a emergent code and 1.49% a life-threatening code. Waiting times were: 52.39 min for non-urgent patients, 40.26 min for urgent, 12.08 for emergent, and 1.19 for life-threatening patients.

Copper and other trace elements strongly bound to humic acids along sediment cores in the Ross Sea, Antarctica

Marine sediment cores sampled in three different areas, during the 1997/98 Italian Antarctic Expedition, were studied. The cores (40 cm) were immediately subdivided into 13 or 14 layers (2-4 cm) in order to obtain a high-depth resolution in the metal content and humic substance analyses. The results obtained for the amount of metals strongly bound to humic acids showed the following order: Cu >> Zn >> Co > As >or= Mn. The fraction of Cu, Zn and As bound to humic acid (microg g(-1) of HA) increases in the first 10-12 cm of cores, then a decrease is observed. This observation could be related both to the presence of a mobile fraction of metals in sediments successively bound to humic acids and to different structural features showed by humic acids along the cores, due to transformation processes. For the other metals a variable pattern along the cores was found.

Uranium daily intake and urinary excretion: a preliminary study in Italy

An estimate was made of daily uranium intake in Italy through human diet and drinking water. The uranium concentration was determined in food, drinking water, and other beverages. Uranium concentration was also determined in a "total diet" sampled in 1999. The total daily dietary intake was estimated to be in the range 2.9-4.8 microg d(-1). The contribution of drinking water to the total uranium intake is sometimes significant as the uranium concentration range in 29 analyzed tap and bottled "mineral" waters is 0.04-5.86 microg L(-1) and the drinking water consumption about 1 L d(-1) or more. Data obtained in this study were compared with data from literature on the uranium daily intake in other countries. Urine samples were collected from 24 male and 14 female occupationally unexposed subjects, 20-50 y of age, living and working in the district of Rome (Italy). The mean concentration found was 10 +/- 7.0 ng L(-1); the inter-subject variability and the daily variability was evaluated. Analyses were performed using ICP-MS.

Thyroid hormone autoantibodies in primary Sjögren syndrome and rheumatoid arthritis are more prevalent than in autoimmune thyroid disease, becoming progressively more frequent in these diseases

To verify the greater prevalence of circulating thyroid hormone autoantibodies (THAb) in primary Sjogren syndrome (SS) vs Hashimoto's thyroiditis (HT) and Graves' disease (GD), we measured THAb in the serum of patients with these 3 diseases who were sampled from 1998-1999 (no.=20, 88, 25) and 1990-1992 (no.=13, 75, 31). Patients with rheumatoid arthritis (RA) (no.=23 and 16) and other collagenoses (no.=20 and 16) were also studied. A third series of patients with these 5 diseases was studied from 1975-1982, and data have been taken into account. THAb were detected using a specific radioimmunoprecipitation method, and their presence was correlated with the presence of TG antibodies (TGAb). We found that IgG antibodies against T3, T4 or both were present with these prevalences in the 1975-1982, 1990-1992 and 1998-1999 series: HT=1, 4, 20%; GD=2, 6, 32%; SS=20, 31, 50%; RA=0, 12, 26%; other collagenoses=0, 0, 0%. The majority of the Sjogren or arthritis cases positive for THAb were negative for TGAb, while the opposite was true for the 2 autoimmune thyroid diseases. We conclude that prevalence of THAb in the 2 non-thyroid autoimmune diseases is greater than in the 2 thyroid autoimmune diseases. In addition, prevalence of THAb is increasing over time regardless of disease. Molecular similarity between extra-thyroid connective proteins (specifically associated to primary SS and RA) and iodinated regions of TG, and an increased preponderance of environmental factors as triggers of autoimmune diseases might account for our findings.

Work restructuring: the process of redefining roles of patient caregivers

Redefining roles of patient caregivers as an element of work restructuring is essential to maintain and/or enhance an organization's efficiency in this competitive health care environment. This process works best when all levels and disciplines within the organization are involved and when meshed with senior management's leadership and vision.