Confocal Imaging at 0.3 THz with depth resolution of a painted wood artwork for the identification of buried thin metal foils

A compact confocal terahertz microscope working at 0.30 THz based on all-solid-state components is used to locate buried thin metal foils in a painted wood artwork. Metal foils are used for decoration, and their precise localization under the pictorial layer is relevant information for conservation scientists and restorers, which can neither be obtained by X-ray radiography nor by spectroscopic imaging in the infrared, as we directly show here. The confocal microscopy principle based on the spatial pinhole concept is here implemented by positioning the first focus of an ellipsoidal reflector at the phase center of horn antennas coupled to Schottky diode detector and emitter mounted in rectangular waveguide blocks, together with an optical beamsplitter. The second focus of the reflector is mechanically scanned inside the sample in three dimensions. The predictions of diffraction theory for a confocal microscope at an imaging wavelength of 1.00 mm with numerical aperture of 0.53 are verified experimentally (1.2 and 2.8 mm for the lateral and the axial resolution, respectively). These values of resolution allow a precise determination of the position of buried metal foils in an ancient piece of art hence making restoration interventions possible

Bowel preparation for elective colorectal resection: multi-treatment machine learning analysis on 6241 cases from a prospective Italian cohort

background current evidence concerning bowel preparation before elective colorectal surgery is still controversial. this study aimed to compare the incidence of anastomotic leakage (AL), surgical site infections (SSIs), and overall morbidity (any adverse event, OM) after elective colorectal surgery using four different types of bowel preparation. methods a prospective database gathered among 78 Italian surgical centers in two prospective studies, including 6241 patients who underwent elective colorectal resection with anastomosis for malignant or benign disease, was re-analyzed through a multi-treatment machine-learning model considering no bowel preparation (NBP; No. = 3742; 60.0%) as the reference treatment arm, compared to oral antibiotics alone (oA; No. = 406; 6.5%), mechanical bowel preparation alone (MBP; No. = 1486; 23.8%), or in combination with oAB (MoABP; No. = 607; 9.7%). twenty covariates related to biometric data, surgical procedures, perioperative management, and hospital/center data potentially affecting outcomes were included and balanced into the model. the primary endpoints were AL, SSIs, and OM. all the results were reported as odds ratio (OR) with 95% confidence intervals (95% CI). results compared to NBP, MBP showed significantly higher AL risk (OR 1.82; 95% CI 1.23-2.71; p = .003) and OM risk (OR 1.38; 95% CI 1.10-1.72; p = .005), no significant differences for all the endpoints were recorded in the oA group, whereas MoABP showed a significantly reduced SSI risk (OR 0.45; 95% CI 0.25-0.79; p = .008). conclusions MoABP significantly reduced the SSI risk after elective colorectal surgery, therefore representing a valid alternative to NBP

Abdominal drainage after elective colorectal surgery: propensity score-matched retrospective analysis of an Italian cohort

background: In italy, surgeons continue to drain the abdominal cavity in more than 50 per cent of patients after colorectal resection. the aim of this study was to evaluate the impact of abdominal drain placement on early adverse events in patients undergoing elective colorectal surgery. methods: a database was retrospectively analysed through a 1:1 propensity score-matching model including 21 covariates. the primary endpoint was the postoperative duration of stay, and the secondary endpoints were surgical site infections, infectious morbidity rate defined as surgical site infections plus pulmonary infections plus urinary infections, anastomotic leakage, overall morbidity rate, major morbidity rate, reoperation and mortality rates. the results of multiple logistic regression analyses were presented as odds ratios (OR) and 95 per cent c.i. results: a total of 6157 patients were analysed to produce two well-balanced groups of 1802 patients: group (A), no abdominal drain(s) and group (B), abdominal drain(s). group a versus group B showed a significantly lower risk of postoperative duration of stay >6 days (OR 0.60; 95 per cent c.i. 0.51-0.70; P < 0.001). a mean postoperative duration of stay difference of 0.86 days was detected between groups. no difference was recorded between the two groups for all the other endpoints. conclusion: this study confirms that placement of abdominal drain(s) after elective colorectal surgery is associated with a non-clinically significant longer (0.86 days) postoperative duration of stay but has no impact on any other secondary outcomes, confirming that abdominal drains should not be used routinely in colorectal surgery

A nonlinear dynamics for risk contagion: analyzing the risk-free equilibrium

In this paper we perform the stability analysis of the risk-free equilibrium point which characterizes a financial contagion dynamics. The model is formulated in the Susceptible-Infected-Recovered approach by employing an analogy between economic sectors and ecosystems. The dynamics is nonlinear and characterized by a time delay which represents a period of financial immunity got after risk infection. In addition, contagion phenomenon is modelled by employing a Holling Type II functional response taking into account an incubation time for risk infection. The analysis around the risk-free steady state is performed in terms of both local asymptotic stability and global asymptotic stability by classical approach. Our results highlight the crucial role of the incubation time in establishing whether risk crisis can be eliminated from the economic sector at the long run, or it continues to exist in

A nonlinear dynamics for risk contagion: analyzing the not risk-free equilibrium

In this paper we carry out the stability analysis of the not risk-free steady state which is involved in a financial contagion dynamics. Starting from an analogy between economic sectors and ecosystems, the Susceptible-Infected-Recovered (SIR) approach is employed to describe the risk dynamics by a nonlinear differential system with time delay. A main assumption is that contagion phenomenon is modelled by a Holling Type II functional response so that an incubation time for risk infection is accounted for; moreover, after contagion, some agents may be recovered from high risk and get a temporary immunity for a temporal period represented by the time delay characterizing the dynamics. We perform the analysis around the not risk-free equilibrium in terms of asymptotic stability and point out the crucial role of the incubation time and the financial immunity period in establishing whether risk crisis continues to exist in the economic sector at the long run or it can be eliminated

A Nonlinear Dynamics for Risk Contagion: Theoretical Remarks

We employ an epidemiological approach to explain how risk may spread in a given economic system. Precisely, the analogy between eco- nomic systems and ecosystems is exploited and an original Susceptible- Infected-Recovered model with time delay is adopted to describe risk contagion by a nonlinear dynamic. The economic player population is divided into a set of distinct compartments, which are defined in terms of risk with low and high level. The time delay represents the period of financial immunity that some agents get from recovery after risk infection. Moreover, the contagion phenomenon is modelled by a Holling Type II functional response, which accounts for an incubation time from the contact between susceptible and infected players up to the actual financial distress. The existence of a unique solution of the proposed delay differential system is stated, moreover the main qualitative features are discussed. Actually, we prove that the dynamics remains positive during the whole-time horizon, and it admits two different stationary states

Neural Responses of Benefiting From the Prosocial Exchange: The Effect of Helping Behavior

Prosocial behavior is critical for the natural development of an individual as well as for promoting social relationships. Although this complex behavior results from gratuitous acts occurring between an agent and a recipient and a wealth of literature on prosocial behavior has investigated these actions, little is known about the effects on the recipient and the neurobiology underlying them. In this study, we used functional magnetic resonance imaging to identify neural correlates of receiving prosocial behavior in the context of real-world experiences, with different types of action provided by the agent, including practical help and effort appreciation. Practical help was associated with increased activation in a network of regions spanning across bilateral superior temporal sulcus, temporoparietal junction, temporal pole, and medial prefrontal cortex. Effort appreciation was associated with activation and increased task-modulated connectivity of the occipital cortex. Prosocial-dependent brain responses were associated with positive affect. Our results support the role of the theory of mind network and the visual cortices in mediating the positive effects of receiving gratuitous help. Moreover, they indicate that specific types of prosocial behavior are mediated by distinct brain networks, which further demonstrates the uniqueness of the psychological processes underlying prosocial actions