TWO NEW SINGLE-EXPOSURE, MULTI-DETECTOR NEUTRON SPECTROMETERS FOR RADIATION PROTECTION APPLICATIONS IN WORKPLACE MONITORING.

This communication describes two new instruments, based on multiple active thermal neutron detectors arranged within a single moderator, that permit to unfold the neutron spectrum (from thermal to hundreds of MeV) and to determine the corresponding integral quantities with only one exposure. This makes them especially advantageous for neutron field characterisation and workplace monitoring in neutron-producing facilities. One of the devices has spherical geometry and nearly isotropic response, the other one has cylindrical symmetry and it is only sensitive to neutrons incident along the cylinder axis. In both cases, active detectors have been specifically developed looking for the criteria of miniaturisation, high sensitivity, linear response and good photon rejection. The calculated response matrix has been validated by experimental irradiations in neutron reference fields with a global uncertainty of 3%. The measurements performed in realistic neutron fields permitted to determine the neutron spectra and the integral quantities, in particular H*(10).

Antibiotic-loaded bone cement reduces risk of infections in primary total knee arthroplasty? A systematic review.

PURPOSE: Antibiotic-loaded bone cement has been widely used for the treatment of infected knee replacement, but its routine use in primary TKA remains controversial. The aim of this systematic review was to analyze the literature about the antimicrobial efficacy and safety of antibiotic-loaded bone cement for its prophylactic use in primary TKA. METHODS: A detailed and systematic search of the Pubmed, Medline, Cochrane Reviews and Google Scholar databases had been performed using the keyword "total knee arthroplasty" "total knee replacement" "total knee prosthesis" and "antibiotic-loaded bone cement" with no limit regarding the year of publication. We used modified Coleman scoring methodology (mCMS) to identify scientifically sound articles in a reproducible format. The review was limited to the English-language articles. RESULTS: Six articles met inclusion criteria. In total, 6318 arthroplasties were included in our study. 3217 of these arthroplasties received antibiotic-loaded bone cement and 3101 arthroplasties served as the control. There was no statistical difference between the two groups in terms of the incidence of deep or superficial surgical site infection. The average mCMS score was 67.6, indicating good methodological quality in the included studies. CONCLUSIONS: Present review did not reveal any significant difference in terms of rate of deep or superficial surgical site infection in patients receiving antibiotic-loaded bone cement compared with the control (plain bone cement) during primary TKA. The clinical relevance of this study was that the use of antibiotic-loaded bone cement did not significantly reduce the risk of infection in primary TKA. LEVEL OF EVIDENCE: III.

A SINGLE-EXPOSURE, MULTIDETECTOR NEUTRON SPECTROMETER FOR WORKPLACE MONITORING.

This communication describes a recently developed single-exposure neutron spectrometer, based on multiple active thermal neutron detectors located within a moderating sphere, which have been developed jointly by CIEMAT (Spain), INFN (Italy) and Politecnico di Milano (Italy) in the framework of Italian and Spanish collaboration projects. The fabricated prototypes permit to achieve spectrometric resolution with nearly isotropic response for neutron with energies from thermal to 100-200 MeV, thus being able to characterise the complete neutron spectrum in only one exposure by unfolding the measured responses of the detectors. This makes it especially advantageous for characterising neutron fields and workplace monitoring purposes in neutron-producing facilities.

The risk for type B aortic dissection in Marfan syndrome.

Marfan syndrome is the most prevalent connective tissue disorder, with an autosomal dominant inheritance with variable penetrance. This paper aims to summarize epidemiology and treatment for type B dissection in Marfan patients.

Endovascular treatment of popliteal aneurysm.

Although traditional surgical repair by aneurysm exclusion and bypass is still considered the gold standard in the treatment of popliteal artery aneurysms (PAAs), the endovascular repair (ER) has been gaining great interest in the last decades. ER offers several advantages over open bypass, including lower morbidity and mortality, and faster functional recovery, but some concerns about migration, occlusion, or fracture remain when a stent graft is deployed across a joint that undergo constant flexion. This review summarizes the current evidence on ER for PAAs. Level I evidence is still very limited, while the majority of published data come from retrospective studies. Moreover the heterogeneity of PAA morphology seems to play a major role in the outcomes after popliteal endografts placement, so that many anatomical criteria should be taken into account to determine which patient is best treated endovascularly. In conclusion, while it is unlike that endovascular treatment may displace open surgical bypass in the near future, it indeed does provide a feasible option for selected patients with high surgical risk and good anatomical features.

Prosthesis infection: prevention and treatment.

Implantation of a vascular prosthesis increases surgical site infection risk by producing a microenvironment conducive to bacterial attachment and biofilm formation, which sustains bacterial colonization and protects encased organisms from host defenses and antimicrobial therapy. Many maneuvers are used in an attempt to reduce infection in arterial reconstructions, but there are no clear guidelines on the most appropriate or effective. As well, there is no good evidence to guide management. A general principle is that indication for removal of the entire infected graft is mandatory when a suture line is involved in the infectious process, an infected anastomotic aneurism and a suture-line hemorrhage is evident, or when a graft-enteric fistula is diagnosed. Conservative, non-resectional management of graft infection is still a respectable solution for selected patients, as those with significant comorbidities, or those where the implanted aortic graft is in a location that precludes excision without causing a high likelihood of morbidity and/or mortality. Anyway, definitive management depends on the patient's condition and a tailored approach should be always offered. Surgical techniques favor in terms of mortality, patency and reinfection rate the in situ reconstruction. Currently, the choice of the technique used relies on center and operator's experience. This article summarizes the incidence of graft infection, analyze the predisponding factors to graft infection, and review current strategies for prevention and treatment of prosthesis and endograft infection.

Development of single-exposure, multidetector neutron spectrometers: the NESCOFI@BTF project.

NESCOFI@BTF is a 3-y project (2011-13) supported by the Scientific Commission 5 of INFN (Italy). The target is the development of neutron spectrometers similar to the Bonner spheres, in terms of response energy interval and accuracy, but able to determine the neutron spectrum in only one exposure. These devices embed multiple (10 to 30) thermal neutron detectors (TNDs) within a single moderator. Two prototypes, called SPherical SPectrometer (SP(2)) and cylindrical spectrometer (CYSP), have been set up. Whilst SP(2) has spherical geometry and nearly isotropic response, the CYSP has cylindrical geometry and is intended to be used as a directional spectrometer. Suitable active TNDs will be embedded in the final version of the devices. The resulting instruments could be used as real-time neutron spectrometers in neutron-producing facilities. This communication describes the design criteria, numerical analysis, experimental issues, state-of-the-art and future developments connected with the development of these instruments.

Diabetic foot: surgical approach in emergency.

Introduction. Critical limb lschemia (CLI) and particularly diabetic foot (DF) are still considered "Cinderella" in our departments. Anyway, the presence of arterial obstructive disease increases the risk of amputation by itself; when it is associated with foot infection, the risk of amputation is greatly increased. Methods. From January 2007 to December 2011, 375 patients with DF infection and CLI have been admitted to our Unit; from 2007 to 2009, 192 patients (Group A) underwent surgical debridement of the lesion followed by a delayed revascularization; from 2010 to 2011, 183 patients (Group B) were treated following a new 4-step protocol: (1) early diagnosis with a 24 h on call DF team; (2) urgent treatment of severe foot infection with an aggressive surgical debridement; (3) early revascularization within 24 hours; (4) definitive treatment: wound healing, reconstructive surgery, and orthesis. We reported rates of mortality, major amputation, and foot healing at 6 months of followup. Results. The majority of patients in both groups were male; no statistical differences in medical history and clinical condition were reported at the baseline. The main difference between the two groups was the mean time from debridement to revascularization (3 days in Group A and 24 hours in Group B). After 6 months of follow-up, mortality was 11% in Group A versus 4.4% in Group B. Major amputation rate was 39.6% and 24.6% in Groups A and B, respectively. Wound healing was achieved in 17.8% in Group A and 20.8% in Group B. Conclusions. This protocol requires a lot of professional skills that should to reach the goal to avoid major amputations in patients with DF. Only an interdisciplinary integrated DF team and an early intervention may significantly impact the outcome of our patients: "Time is Tissue"!

Endovascular first as "preliminary approach" for critical limb ischemia and diabetic foot.

The treatment of the critical limb ischemia (CLI) and diabetic foot (DB) is still object of discussion and the gold standard for revascularization has not yet been identified. In these two decades the introduction of endovascular procedures had a large impact on the surgical revascularization and were added to the practice of vascular surgeons in patients who cannot be candidates for a bypass. This may be due to significant comorbidities, a reduced life expectancy, infection or gangrene in the possible sites of distal anastomoses, the unavailability of suitable veins, or the absence of an adequate "landing zone" for the distal part of the bypass. Various studies have evaluated the role of PTA in DF and CLI that resulted favourable in terms of feasibility, technical efficacy, the reduced number of complications, and limb salvage rates. Anyway, long-term patency is better after bypass surgery than after angioplasty, which is burdened by a high restenosis rate. In our experience we tried to practice endovascular approach as a first choice. If the procedure cannot be concluded safely, we continue the intervention surgically or use a hybrid approach. The endovascular-first strategy seems to be the future regardless of comorbidity of the patient and the degree of pathology. The vascular surgeon remains the only specialist that can decide the correct intervention without pressure or been forced and, last but not least, the only one who can independently perform hybrid interventions.

The role of hybrid procedures in the treatment of critical limb ischemia.

Patients affected by critical limb ischemia (CLI) represent a complex and high risk clinical problem, and a multidisciplinary approach is often demanded. The amputation rate in patients affected by CLI is still high. Introduction of endovascular procedure shook up the CLI concept of treatment. The increasing experience of Vascular Surgeons in endovascular technique forced these specialist to match classic surgical skills and endovascular tools in order to achieve the best treatment for each patients. The combination of the two techniques identifies the hybrid procedure. Aim of this paper is to define indication, necessity and results of the hybrid procedure in patients suffering from CLI.

Current drive at plasma densities required for thermonuclear reactors.

Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors.

Test of "crab-waist" collisions at the DAPhiNE Phi factory.

The electron-positron collider DAPhiNE, the Italian Phi factory, has been recently upgraded in order to implement an innovative collision scheme based on large crossing angle, small beam sizes at the crossing point, and compensation of beam-beam interaction by means of sextupole pairs creating a "crab-waist" configuration in the interaction region. Experimental tests of the novel scheme exhibited an increase by a factor of 3 in the peak luminosity of the collider with respect to the performances reached before the upgrade. In this Letter we present the new collision scheme, discuss its advantages, describe the hardware modifications realized for the upgrade, and report the results of the experimental tests carried out during commissioning of the machine in the new configuration and standard operation for the users.

Observations of the vacuum ultraviolet and x-ray brightness profiles of Fe, Ni, and Ge in magnetically confined fusion plasmas.

The spatial brightness profiles of emission lines for the K-like through He-like ionization states of Fe, Ge, and Ni have been measured during a set of experiments in which Fe and Ge were introduced into FTU tokamak plasmas by using the laser blowoff technique. Nickel was an intrinsic impurity observed during these experiments that was sputtered from the inconel limiter. The brightness profiles were measured by spatially scanable, photometrically calibrated vaccum ultraviolet and x-ray spectrometers that covered the 1 to 1700 A region. Simulations of these profiles and the time evolution of the laser blowoffs were performed with the MIST transport code using several sets of atomic physics compilations [ADPAK (originally in MIST), Arnaud and Raymond (AR92), Arnaud and Rothenflug (AR85), Mazzotta et al., and Mattioli (an extension to Mazzotta)]. The goal was to determine which set of available rates could best simulate the measured spatial brightness profiles and the charge state balance in the plasma. The Mazzotta et al. (for Fe and Ni), the Mattioli (for Ge), and the AR92 (for Fe only) rates adequately simulated the He-, Li-, Be-, Na-, Mg-like ionization states. The F- to B-like charge states could not be simulated by these compilations unless the relevant dielectronic rates were multiplied by a factor of 2. The ADPAK rates could not adequately predict any of the charge states of Fe, Ge, or Ni.

Cosmic rays observed by the resonant gravitational wave detector NAUTILUS

The passage of cosmic rays has been observed to excite mechanical vibrations in the resonant gravitational wave detector NAUTILUS operating at temperature of 100 mK. A very significant correlation (more than 10 standard deviations) is found.