Perspectives in linear accelerator for FLASH VHEE: Study of a compact C-band system.

PURPOSE: In order to translate the FLASH effect in clinical use and to treat deep tumors, Very High Electron Energy irradiations could represent a valid technique. Here, we address the main issues in the design of a VHEE FLASH machine. We present preliminary results for a compact C-band system aiming to reach a high accelerating gradient and high current necessary to deliver a Ultra High Dose Rate with a beam pulse duration of 3µs. METHODS: The proposed system is composed by low energy high current injector linac followed by a high acceleration gradient structure able to reach 60-160 MeV energy range. To obtain the maximum energy, an energy pulse compressor options is considered. CST code was used to define the specifications RF parameters of the linac. To optimize the accelerated current and therefore the delivered dose, beam dynamics simulations was performed using TSTEP and ASTRA codes. RESULTS: The VHEE parameters Linac suitable to satisfy FLASH criteria were simulated. Preliminary results allow to obtain a maximum energy of 160 MeV, with a peak current of 200 mA, which corresponds to a charge of 600 nC. CONCLUSIONS: A promising preliminary design of VHEE linac for FLASH RT has been performed. Supplementary studies are on going to complete the characterization of the machine and to manufacture and test the RF prototypes.

Selection rules for the orbital angular momentum of optically produced THz radiation.

In this work, we theoretically study the transduction of orbital angular momentum (OAM) l for infrared pump lasers into the THz domain. In the case of optical rectification, the transduction of OAM occurs only through a spin-orbit interaction, with the selection rule on the OAM l=0 valid for any kind of polarization of the pump, which means that there is no transfer of OAM along the propagation axis. In difference frequency generation, the selection rule for the difference Δl between the OAM of the pump fields with linear or circular polarization is l=Δl, whereas l ranges from Δl-2 to Δl+2 in cases of both radial and azimuthal polarization. Moreover, for THz generation in the latter case, the high diffraction obtained with tightly focused pumps yields l tending to Δl±2, while l tends to zero in the opposite case of large pump beams.

Evaluation of the intra- and inter-method agreement of brain MRI segmentation software packages: A comparison between SPM12 and FreeSurfer v6.0.

PURPOSE: The lack of inter-method agreement can produce inconsistent results in neuroimaging studies. We evaluated the intra-method repeatability and the inter-method reproducibility of two widely-used automatic segmentation methods for brain MRI: the FreeSurfer (FS) and the Statistical Parametric Mapping (SPM) software packages. METHODS: We segmented the gray matter (GM), the white matter (WM) and subcortical structures in test-retest MRI data of healthy volunteers from Kirby-21 and OASIS datasets. We used Pearson's correlation (r), Bland-Altman plot and Dice index to study intra-method repeatability and inter-method reproducibility. In order to test whether different processing methods affect the results of a neuroimaging-based group study, we carried out a statistical comparison between male and female volume measures. RESULTS: A high correlation was found between test-retest volume measures for both SPM (r in the 0.98-0.99 range) and FS (r in the 0.95-0.99 range). A non-null bias between test-retest FS volumes was detected for GM and WM in the OASIS dataset. The inter-method reproducibility analysis measured volume correlation values in the 0.72-0.98 range and the overlap between the segmented structures assessed by the Dice index was in the 0.76-0.83 range. SPM systematically provided significantly greater GM volumes and lower WM and subcortical volumes with respect to FS. In the male vs. female brain volume comparisons, inconsistencies arose for the OASIS dataset, where the gender-related differences appear subtler with respect to the Kirby dataset. CONCLUSIONS: The inter-method reproducibility should be evaluated before interpreting the results of neuroimaging studies.

When traditions become dangerous: Intestinal perforation from unusual foreign body-Case report and short literature review.

Gastrointestinal perforation (GI) is a common cause of acute abdomen in the emergency department that needs a prompt surgery intervention. Nowadays, CT examinations represent the method of choice to image patients with acute abdominal pain in emergency. GI perforations by foreign bodies ingested is rare and only <1% of ingested foreign bodies are believed to cause perforation of GI. MDCT is to be considered the best imaging method for identifying foreign bodies, the perforation site and the surgical treatment to be planned reliably. We presente a case of 70-year-old lady presented to our Emergency Department with acute abdominal pain.

Design and optimization of a compact laser-driven proton beamline.

Laser-accelerated protons, generated by irradiating a solid target with a short, energetic laser pulse at high intensity (I > 1018 W·cm-2), represent a complementary if not outperforming source compared to conventional accelerators, due  to their intrinsic features, such as high beam charge and short bunch duration. However, the broadband energy spectrum of these proton sources is a bottleneck that precludes their use in applications requiring a more reduced energy spread. Consequently, in recent times strong effort has been put to overcome these limits and to develop laser-driven proton beamlines with low energy spread. In this paper, we report on beam dynamics simulations aiming at optimizing a laser-driven beamline - i.e. a laser-based proton source coupled to conventional magnetic beam manipulation devices - producing protons with a reduced energy spread, usable for applications. The energy range of investigation goes from 2 to 20 MeV, i.e. the typical proton energies that can be routinely obtained using commercial TW-power class laser systems. Our beamline design is capable of reducing the energy spread below 20%, still keeping the overall transmission efficiency around 1% and producing a proton spot-size in the range of 10 mm2. We briefly discuss the results in the context of applications in the domain of Cultural Heritage.

Prosthetic management of patients with oro-maxillo-facial defects: a long-term follow-up retrospective study.

INTRODUCTION: The aim of this study is to determine the outcome of maxillofacial prosthetic rehabilitation after oncological resections, including both intra- and extra-oral prosthetic devices. METHODS: In this study were included 72 patients, who have undergone an intra or extra-oral maxillofacial prosthetic rehabilitation after an oncologic resection. Tumors on the head and neck were analyzed and the defects of these resections have been divided in two different groups: intra and extra-oral defects. RESULTS: 72 participants were treated with maxillofacial prosthesis, 3 of which with post-traumatic wounds and 69 with resections of tumors on the head and neck. Of the 69 treated for neoplastic disease, 43 received an intraoral prosthesis (palatal obturator) and 29 with an extraoral epithesis (18 with nasal prostheses, 8 with orbital implants and 3 with ear implants). The group included patients with different types of tumors. All the patients were evaluated in terms of aesthetic appearance after the construction of the prostheses and the results were satisfactory. CONCLUSION: Within the limitations of this study, after the use of maxillofacial protheses patients feel more confident and self-assured. Maxillofacial protheses are a good solution in order to improve the life's quality in patients with tumors resections: prostheses are easy to handle and provide a satisfying social interaction for the patients.

Temporal Narrowing of Neutrons Produced by High-Intensity Short-Pulse Lasers.

The production of neutron beams having short temporal duration is studied using ultraintense laser pulses. Laser-accelerated protons are spectrally filtered using a laser-triggered microlens to produce a short duration neutron pulse via nuclear reactions induced in a converter material (LiF). This produces a ∼3 ns duration neutron pulse with 10(4) n/MeV/sr/shot at 0.56 m from the laser-irradiated proton source. The large spatial separation between the neutron production and the proton source allows for shielding from the copious and undesirable radiation resulting from the laser-plasma interaction. This neutron pulse compares favorably to the duration of conventional accelerator sources and should scale up with, present and future, higher energy laser facilities to produce brighter and shorter neutron beams for ultrafast probing of dense materials.

Topology of megagauss magnetic fields and of heat-carrying electrons produced in a high-power laser-solid interaction.

The intricate spatial and energy distribution of magnetic fields, self-generated during high power laser irradiation (at Iλ^{2}∼10^{13}-10^{14} W.cm^{-2}.µm^{2}) of a solid target, and of the heat-carrying electron currents, is studied in inertial confinement fusion (ICF) relevant conditions. This is done by comparing proton radiography measurements of the fields to an improved magnetohydrodynamic description that fully takes into account the nonlocality of the heat transport. We show that, in these conditions, magnetic fields are rapidly advected radially along the target surface and compressed over long time scales into the dense parts of the target. As a consequence, the electrons are weakly magnetized in most parts of the plasma flow, and we observe a reemergence of nonlocality which is a crucial effect for a correct description of the energetics of ICF experiments.

Characterization of the THz radiation source at the Frascati linear accelerator.

The linac driven coherent THz radiation source at the SPARC-LAB test facility is able to deliver broadband THz pulses with femtosecond shaping. In addition, high peak power, narrow spectral bandwidth THz radiation can be also generated, taking advantage of advanced electron beam manipulation techniques, able to generate an adjustable train of electron bunches with a sub-picosecond length and with sub-picosecond spacing. The paper reports on the manipulation, characterization, and transport of the electron beam in the bending line transporting the beam down to the THz station, where different coherent transition radiation spectra have been measured and studied with the aim to optimize the THz radiation performances.

The contribution of sublingual immunotherapy to the achievement of control in birch-related mild persistent asthma: a real-life randomised trial.

BACKGROUND: Asthma control represents the main goal of asthma management and different strategies aim to avoid the long term downsides of inhaled corticosteroids. We investigated in real-life conditions the contribution of sublingual immunotherapy in achieving the control of birch-related mild persistent asthma compared to two usual step-up therapeutic options. METHODS: A three-year open randomised study included 84 asthmatics, uncontrolled during the previous birch pollen season, despite a treatment with budesonide 400µg/day. Patients randomly received budesonide 800µg/day, budesonide 1600µg/day, budesonide 400µg/day plus montelukast 10µg/day and budesonide 400µg/day plus carbamylated allergoid of betulaceae pre-coseasonally. Asthma Control test, combined allergy symptoms and medications score, albuterol consumption, lung function, nasal eosinophils and nasal steroids usage were assessed as changes from the first to last pollen season. RESULT: Seventy-six patients concluded the study. All options, except budesonide 800µg/day, produced an improvement of mean monthly Asthma Control test (p<0.05). Patients undergoing low-dose budesonide plus immunotherapy achieved, after three years, an appreciable control (ACT mean score 24). A significant improvement was seen in all groups for allergy symptoms plus medications and bronchial reactivity. Albuterol consumption and lung function improved in all but the first group. Only budesonide plus immunotherapy reduced nasal eosinophils and nasal steroids usage. Two mild self-resolving adverse events were reported. CONCLUSIONS: For patients with respiratory allergy due to birch pollen and mild persistent asthma, sublingual immunotherapy added to low-dose inhaled corticosteroids appears effective in maintaining long-term seasonal asthma control, representing a safe opportunity to reduce the cumulative amount of delivered corticosteroids.

Lethal injuries following building collapse: comparison between autopsy and radiographic findings.

PURPOSE: The aim of this study was to evaluate the impact of conventional radiology on the assessment of causes of death of human beings after a building collapse and to establish whether the radiographic approach is useful and justifiable. MATERIALS AND METHODS: Eight victims of a building collapse were subjected to autopsy, toxicology and radiographic examinations of the entire body. The autopsy findings, classified into three groups according to the New Injury Severity Score (NISS), were compared with radiographic findings. RESULTS: The death of the three individuals in group 1 was ascribed to mechanical asphyxia. Costal fractures, pneumothorax and subcutaneous emphysema were detected in one case only. The three individuals in group 2 died of mechanical asphyxia associated with cerebral injuries in all cases, abdominal injuries in two and cardiac injuries in one. Plain films showed skull fracture in one case, air within the cardiac chambers in another and diaphragmatic injuries in the third. The two individuals in group 3 died of injuries not compatible with life at the cardiac and abdominal level in both cases and at the cerebral level in one. Radiography showed multiple fractures of the cranium associated with diaphragmatic injuries in one case only. No significant pleuropulmonary radiographic findings were detected in any of the eight victims. Paralytic ileus, identified in all patients, is not strictly correlated to abdominal injuries. Skeletal injuries were all confirmed at conventional radiography. CONCLUSIONS: Conventional radiography allows for the overall assessment of skeletal injuries. Radiographic findings provide limited information about the causes of death, whereas findings related to the concomitant causes of death are more frequent. Conventional radiography should be considered inadequate, especially if the potential of the modern software tools available on current computed tomography and magnetic resonance images is considered.

Five year prognosis of an Italian cohort of juvenile acute myocardial infarction patients.

AIM: The aim of this study was to describe the five-year prognosis of an Italian cohort of patients following acute myocardial infarction (AMI) occurred at age ≤ 45 years and to investigate the potential role of risk predictors for future cardiovascular events (CVE). METHODS: The study enrolled 112 consecutive patients aged ≤ 45 years admitted to our Coronary Care Unit between March 1995 and January 2007 because of AMI. Clinical characteristics, extent of coronary vessel disease by angiogram and cardiovascular risk factors (including diet, physical activity, alcohol and coffee consumption) were registered. RESULTS: Complete follow-up data was available for 104 (93%) patients with a duration of follow-up of 5.3 (2.9-7.6) years. Twenty-four (23%) patients presented with a new CVE: 16 (15%) angina pectoris, 6 (6%) recurrent AMI, one heart failure and one cardiac death. One in every five patients presented left ventricle systolic function below 50%. Multivariate analysis (Cox proportional regression model) proved physical activity as an independent predictor of new CVE occurrence (P=0.014). Patients who practised moderate aerobic physical activity for at least two hours per week following AMI had significantly higher event-free survival compared with inactive controls (P=0.029). CONCLUSION: Five-year prognosis of juvenile AMI is poor, with one in every five patients presenting a new CVE. Based on the present cohort of patients physical activity following first event plays a relevant prognostic role, supporting the need of careful lifestyle counselling.

Experimental demonstration of emittance compensation with velocity bunching.

In this Letter we report the first experiments aimed at the simultaneous demonstration of the emittance compensation process and velocity bunching in a high brightness electron source, the SPARC photoinjector in INFN-LNF. While a maximum compression ratio up to a factor 14 has been observed, in a particular case of interest a compression factor of 3, yielding a slice current of 120 A with less than 2 microm slice emittance, has been measured. This technique may be crucial in achieving high brightness beams in photoinjectors aiming at optimized performance of short wavelength single-pass free electron lasers or other advanced applications in laser-plasma accelerators.

Percutaneous aortic valve replacement in two cases at high surgical risk: procedural details and implications for patient selection.

The morbidity and mortality burden of heart valve disease is increasing in the developing world, especially among the elderly. Whereas surgery remains the standard of care in fit patients with degenerative aortic stenosis, percutaneous aortic valve replacement could become an effective alternative to surgery in selected higher risk patients. The authors report on two women with aortic stenosis, both at high surgical risk (an 81-year-old female with coronary artery and cerebro-vascular disease, and a 70-year-old female with end-stage cirrhosis), in whom percutaneous valve replacement was effectively performed by means of transfemoral access and retrograde CoreValve Re-valving System implantation. Two major post-procedural complications occurred, both effectively managed, in the second patient: a third degree atrio-ventricular block (requiring permanent pace-maker implantation) and bleeding from the right femoral artery access (requiring implantation of two covered stents and blood transfusion). Despite the increased baseline risk, both patients were discharged asymptomatic, the first twelve days and the other three weeks after admission. In the authors' experience percutaneous aortic valve replacement can be performed with reasonable safety in patient with severe aortic stenosis at high surgical risk.

A cardioplegia circuit with versatility: the 'ReVerse' system. How to do it.

Various methods of cardioplegia administration have been used in cardiac surgery: crystalloid, blood and mixed crystalloid/blood. Each of these types of cardioplegia administration typically needs a different circuit. This may correspond to an increase in cost and the time needed to change the circuit if required. When various modifications are performed on the circuit, this also increases the risk of contamination. In order to simplify the management of differing cardioplegia circuits, we devised one circuit for all solutions in all situations by adding one modification. The ReVerse cardioplegia circuit system is a description of a two-pump cardioplegia circuit which is adaptable to either blood or crystalloid cardioplegia. The change from one mode to another requires a manoeuvre of two clamps, allowing the blood solution to travel through shunt tubing into the apposite pumphead. In our experience the versatility of this circuit is a fast, safe method to administrate all types of cardioplegia solution, saving the space taken up by storing multiple circuits.

[Smoking while driving and its consequences on road safety]. / Le implicazioni sulla sicurezza stradale del fumare durante la guida.

The study was focused on the risk assessment of distraction of smoking habits while driving vehicles. We have compared the results with the data about driving distraction using mobile phone without voice devices. We video-recorded 10 smokers, 4 male and 6 female, smoking while driving a car The average of measured driving distraction of smokers is about 12 seconds. It means to cover a distance of 160 metres with a speed of 50 Km/h. Comparing to the use of mobile phone, the data of driving distraction show a duration of 10.6 seconds, that means to cover a distance of 150 metres at the speed of 50 Km/h. This result suggest that cigarette smoking produces a remarkable risk for road safety, more than the mobile phone use. In addiction to the conditions that produce a considerable driving distraction of smokers, we underline a demonstrated shortage of oxygen, the presence of carbon monoxide and hight concentration offine particulate in the air breathed inside the vehicle. We also consider another aspect related to smoking habits while driving vehicles: the environmental damage. In fact throwing cigarette outside, while the vehicle is moving, is the prevalent reason of setting fire to the edge of the road. This study proposes to make changes in the laws and regulation on road safety in order to fine smokers behaviour during vehicle driving. Furthermore it seems necessary to promote public information about those risks among people.

Erionite and asbestos differently cause transformation of human mesothelial cells.

Malignant mesothelioma (MM) is an aggressive tumor associated with environmental or occupational exposure to asbestos fibers. Erionite is a fibrous zeolite, morphologically similar to asbestos and it is assumed to be even more carcinogenic. Onset and progression of MM has been suggested as the result of the cooperation between asbestos and other cofactors, such as SV40 virus infection. Nevertheless, several cases of MM were associated with environmental exposure to erionite in Turkey, where SV40 was never isolated in MM specimens. We show here that erionite is poorly cytotoxic, induces proliferating signals and high growth rate in human mesothelial cells (HMC). Long term exposure to erionite, but not to asbestos fibers, transforms HMC in vitro, regardless of the presence of SV40 sequences, leading to foci formation in cultured monolayers. Cells derived from foci display constitutive activation of Akt, NF-kappaB and Erk1/2, show prolonged survival and a deregulated cell cycle, involving cyclin D1 and E overexpression. Our results reveal that erionite is able per se to turn HMC into transformed highly proliferating cells and disclose the carcinogenic properties of erionite, prompting for a careful evaluation of environmental exposure to these fibers. The genetic predisposition to the effect of erionite is a separate subject for investigation.

Direct measurement of the double emittance minimum in the beam dynamics of the sparc high-brightness photoinjector.

In this Letter we report the first experimental observation of the double emittance minimum effect in the beam dynamics of high-brightness electron beam generation by photoinjectors; this effect, as predicted by the theory, is crucial in achieving minimum emittance in photoinjectors aiming at producing electron beams for short wavelength single-pass free electron lasers. The experiment described in this Letter was performed at the SPARC photoinjector site, during the first stage of commissioning of the SPARC project. The experiment was made possible by a newly conceived device, called an emittance meter, which allows a detailed and unprecedented study of the emittance compensation process as the beam propagates along the beam pipe.

Hypofibrinogenaemia caused by a novel FGG missense mutation (W253C) in the gamma chain globular domain impairing fibrinogen secretion.

BACKGROUND: Inherited disorders of fibrinogen are rare and affect either the quantity (hypofibrinogenaemia and afibrinogenaemia) or the quality of the circulating fibrinogen (dysfibrinogenaemia). Extensive allelic heterogeneity has been found for all three disorders: in congenital afibrinogenaemia >30 mutations, the majority in FGA, have been identified in homozygosity or in compound heterozygosity. Several mutations have also been identified in patients with hypofibrinogenaemia; many of these are heterozygous carriers of afibrinogenaemia null mutations. OBJECTIVE: To report the case of a patient from Slovakia diagnosed with hypofibrinogenaemia characterised by fibrinogen concentrations of around 0.7 g/l. RESULTS: The patient was found to be heterozygous for a novel missense mutation W253C (W227C in the mature protein) in the C-terminal globular domain of the fibrinogen gamma chain. Co-expression of the W253C FGG mutant cDNA (fibrinogen Bratislava) in combination with wild-type FGA and FGB cDNAs showed that fibrinogen molecules containing the mutant gamma chain can assemble intracellularly but are not secreted into the media, confirming the causative nature of the identified mutation. CONCLUSIONS: Current analysis of fibrinogen Bratislava indicates that the domains important for the processes of hexamer assembly and hexamer secretion should not be considered as strictly restricted to one or other fibrinogen chain.