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A microdosimetric characterization of the 62 MeV proton beam line of CATANA has been performed all along the Spread Out Bragg Peak with three different detectors. Two silicon detectors and a Tissue Equivalent Proportional Counter measured at approximately the same depths of the SOBP. The TEPC is a new miniaturized gas counter developed at the Legnaro National Laboratories of INFN, modified to work without gas flow. The first silicon detector has been developed at the Politecnico of Milano and it is a monolithic telescope composed by a matrix of 2 µm thick cylindrical diodes with a diameter 9 µm. that compose the ΔE layer. The E and ΔE layers are fabricated on a single substrate of silicon. The third detector is the MicroPlus probe developed at the CMRP - University of Wollongong, it is an array of 3D sensitive volumes each with dimension 30x30 µm and 10 µm thick fabricated on SOI. Measurements performed with the three detectors are presented and discussed.

Objectives Off-pump coronary artery bypass grafting (OPCAB) may have advantages in the elderly. Although proven safe, it remains unclear whether OPCAB provides a short-term survival benefit in octogenarians. We sought to compare outcomes using propensity matching between OPCAB and conventional surgery in a statewide database. Methods We identified all octogenarians (≥ 80 years) who underwent isolated coronary artery bypass grafting (CAB) at 10 different centers in the state of Maryland from July 2011 to June 2016. We separated patients into two groups: OPCAB and on-pump coronary artery bypass (ONCAB). Patients were assigned propensity scores with a semi-parsimonious logistic regression model and matched 1:1 by the nearest-neighbor principle. A revascularization ratio was determined between the number of distal grafts sewn and number of diseased coronaries (≥ 50% stenosis). Results In total, 926 octogenarians underwent isolated CAB (8.2% of all CAB): 798 (86%) had ONCAB and 128 (14%) had OPCAB. Propensity matching yielded 128 well-matched pairs. Operative mortality was similar between groups (OPCAB 5.5% vs ONCAB 3.1%, p  = 0.364). Rates of complications were similar between groups. OPCAB patients had a lower revascularization ratio (0.92 vs 1.15, p  < 0.001), but more frequent use of left internal mammary artery (97 vs 89%, p  = 0.017), and decreased intraoperative transfusion rates (33 vs 63%, p  < 0.001). Conclusions In comparing outcomes among octogenarians across the state of Maryland, OPCAB and ONCAB had similar mortality and morbidity. However, OPCAB was associated with a lower revascularization ratio. Thus, our results demonstrate no short-term survival benefit of OPCAB over ONCAB in octogenarians.

The tissue equivalent proportional counter (TEPC) is the most accurate device for measuring the microdosimetric properties of a particle beam, nevertheless no detailed information on the track structure of the impinging particles can be obtained, since the lower operation limit of common TEPCs is about 0.3 μm. On the other hand, the pattern of particle interactions is measured by track-nanodosimetry, which derives the single-event distribution of ionization cluster size at the nanometric scale. Anyway, only three nanodosimeters are available worldwide. A feasibility study for extending the performances of TEPC down to the nanometric region was performed and a novel avalanche-confinement TEPC was designed and constructed. This detector is constituted by a cylindrical chamber, based on a three-electrode structure, connected to a vacuum and gas flow system to ensure a continuous replacement of the tissue equivalent gas, thus allowing to simulate different biological site sizes in the range 300-25 nm. This TEPC can be calibrated by exploiting a built-in alpha source and a miniaturized solid-state detector as a trigger. Irradiations with photons, fast neutrons and two hadron beams demonstrated the good performances of the device. A satisfactory agreement with FLUKA simulations was obtained.

Background We sought to quantify the effect of severe postoperative bleeding in hemodynamically stable patients following cardiac surgery. Methods We reviewed the charts of all cardiac surgery patients operated on at our institution between 2010 and 2014. After excluding patients with tamponade or MAP <60, we propensity matched patients having chest tube output >300 mL in the first postoperative hour, >200 mL in the second, and >100 mL in the third (“bleeding” group) with patients having <50 mL/h of chest tube output (“dry” group). The primary outcome was a composite of morbidity or mortality (excluding reexploration). Results 5016 patients were operated on between 2010 and 2014; of these, we included the records of 84 bleeding and 498 dry patients. Propensity matching resulted in 68 pairs of patients well-matched on baseline and operative variables. As compared to matched dry patients, bleeding patients were more likely to experience the primary outcome of any morbidity/mortality (36.8 vs. 13.2 %, p  = 0.002), as well as ventilation >24 h (33.8 vs. 7.4 %, p  < 0.001) and 30-day mortality (11.8 vs. 1.5 %, p  = 0.02). Of the 84 bleeding patients, 46 underwent reexploration for bleeding within 24 h of surgery. A subgroup analysis propensity matching bleeding patients who were or were not reexplored <24 h demonstrated similarly poor outcomes in each group (primary outcome, 44.7 % reexplored vs. 50.0 % non-reexplored, p  = 0.65), though reexplored patients were far less likely to require hematoma evacuation/washout >24 h after surgery (0 vs. 18.4 %, p  = 0.005). Conclusions Even among hemodynamically stable patients, severe bleeding is associated with markedly worse outcomes following cardiac surgery.