On the role of secondary motions in turbulent square duct flow

We use a direct numerical simulations (DNS) database for turbulent flow in a square duct up to bulk Reynolds number \Rey_b=40000, to quantitatively analyze the role of secondary motions on the mean flow structure. For that purpose we derive a generalized form of the identity of Fukagata, Iwamoto and Kasagi (FIK), which allows to quantify the effect of cross-stream convection on the mean streamwise velocity, wall shear stress and bulk friction coefficient. Secondary motions are found to contribute for about $6\%$ of total friction, and to act as a self-regulating mechanism of turbulence whereby wall shear stress nonuniformities induced by corners are equalized, and universality of the wall-normal velocity profiles is established. We also carry out numerical experiments whereby the secondary motions are artificially suppressed, in which case their equalizing role is partially taken by the turbulent stresses

Random Forests model selection

Random Forests (RF) of tree classifiers are a popular ensemble method for classification. RF have shown to be effective in many different real world classification problems and nowadays are considered as one of the best learning algorithms in this context. In this paper we discuss the effect of the hyperparameters of the RF over the accuracy of the final model, with particular reference to different theoretically grounded weighing strategies of the tree in the forest. In this way we go against the common misconception which considers RF as an hyperparameter-free learning algorithm. Results on a series of benchmark datasets show that performing an accurate Model Selection procedure can greatly improve the accuracy of the final RF classifier

Structural analysis of the double-walled copper-steel cryogenic chamber of the ASTAROTH experiment

This document describes the verification process of structural performance of the double- walled copper-steel cryogenic chamber of the ASTAROTH (All Sensitive crysTal ARray with lOw THreshold) experiment and the evaluation of the stresses generated near the thermal bridge connecting the inner and outer wall. The chamber consists of an external AISI 316L stainless steel dewar and an inner double-walled OF (Oxygen Free) copper dewar connected to an AISI 316L stainless steel flanged collar. The results showed that close to the thermal bridge (copper-steel junction) the stresses slightly exceed the YS of copper at the estimated operating temperature (localised strain-hardening condition). On the other hand, the safety coefficient respect to fracture is well above one for both materials. This condition, together with the fact that limited cooling cycles are expected during the operating life of the system, leads to the assumption that a progressive material hardening will occur in this area, thus locally raising the YS limit

Extravasation injury of balanced electrolyte solution simulates the clinical condition of necrotizing fasciitis: A case report

Extravasation injury (EI) is an iatrogenic condition that occurs preferentially in neonatal and pediatric patients when the injection of fluid substances by intravenous access is required and it accidentally leaks into the adjacent tissues or in spaces outside of vascular compartment. Different types and amount of substances once undergoing extravasation can affect the EI differently [1]. In some instances immediate measures such as saline washout, local antidotes, enzymatic debridement and surgical interventions can be required in order to prevent the occurrence of a growing injury avoiding the progression of the EI to a medical emergency [6]. Here we report an unusual case of a preterm 2-month-old male patient in which the extravasation of balanced electrolyte solution on the upper right arm resulted in the development of full-thickness skin necrosis appearing as the clinical condition of necrotizing fasciitis. The management of necrotic tissue was performed using escharectomy as well as autograft skin under conditions of general anesthesia

Economic Burden of Denatured Alcohol-Induced Burns: A 20-Year Retrospective Study

: Burn care has rapidly improved over the past decades, but health innovations are expensive. We present the first study focusing on the economic burden of exclusive denatured alcohol-induced burns. The goal of this study was to determine costs for the public health system due to inpatients' burn care because of these specific burns. Moreover, we aimed to observe the incidence of methylated spirit-related burns in the past 20 years. We performed an observational retrospective study in our burn unit including all patients with a denatured alcohol-related burn injury from 1 January 2001 to 31 December 2020. A total of 503 patients with a mean burn size of 24% were hospitalized; the mean annual total costs per patient was €43,879, varying from €31,518 to €63,274.00€; the total costs for denatured alcohol-related burns during the period 2001-2020 was €21,145,076. We noted an increasing incidence of denatured alcohol-related burns and related costs over the years, especially in the last decade. Our results highlight that burns by methylated spirits are still a real and expanding problem. Therefore, authorities should focus on sales rules, characteristics of the containers, and education of people who misuse denatured alcohol, based on historical habits of use. To reduce the socioeconomic costs of burns, future intervention strategies and studies from the dermatology community and burn specialists should focus on prevention programs and prompt wound healing to shorten the length of hospital stay, enable quick return to work, and improve the outcomes of patients with burns

RE: Few Comments on: "Musculoskeletal Applications of Elastography: A Pictorial Essay of Our Initial Experience"

author reply 25

Targeted and untargeted quantification of quorum sensing signalling molecules in bacterial cultures and biological samples via HPLC-TQ MS techniques

Quorum sensing (QS) is the ability of some bacteria to detect and to respond to population density through signalling molecules. QS molecules are involved in motility and cell aggregation mechanisms in diseases such as sepsis. Few biomarkers are currently available to diagnose sepsis, especially in high-risk conditions. The aim of this study was the development of new analytical methods based on liquid chromatography-mass spectrometry for the detection and quantification of QS signalling molecules, including N-acyl homoserine lactones (AHL) and hydroxyquinolones (HQ), in biofluids. Biological samples used in the study were Pseudomonas aeruginosa bacterial cultures and plasma from patients with sepsis. We developed two MS analytical methods, based on neutral loss (NL) and product ion (PI) experiments, to identify and characterize unknown AHL and HQ molecules. We then established a multiple-reaction-monitoring (MRM) method to quantify specific QS compounds. We validated the HPLC-MS-based approaches (MRM-NL-PI), and data were in accord with the validation guidelines. With the NL and PI MS-based methods, we identified and characterized 3 and 13 unknown AHL and HQ compounds, respectively, in biological samples. One of the newly found AHL molecules was C12-AHL, first quantified in Pseudomonas aeruginosa bacterial cultures. The MRM quantitation of analytes in plasma from patients with sepsis confirmed the analytical ability of MRM for the quantification of virulence factors during sepsis

Prognostic role of aspartate aminotransferase-lymphocyte ratio index in patients with metastatic colorectal cancer: results from the randomized ITACa trial

BACKGROUND: The aim of this study was to investigate the role of pre-treatment aspartate aminotransferase-lynphocyte ratio (ALRI) as a predictor of prognosis and treatment efficacy in patients with metastatic colorectal cancer (mCRC) enrolled in the prospective multicenter randomized ITACa (Italian Trial in Advanced Colorectal Cancer) trial to receive first-line chemotherapy (CT) + bevacizumab (B) or CT alone. PATIENTS AND METHODS: Patients randomly received CT+B or CT alone as first-line therapy. CT consisted of either FOLFOX4 or FOLFIRI at the clinician's discretion. RESULTS: Out of the 284 patients enrolled, increased ALRI levels were associated with shorter PFS and OS (p<0.0001). At baseline, median PFS was 10.3 months (95% CI 9.4-12.0) and 8.0 months (95 % CI 6.8-8.9), and median OS was 25.2 months (95 % CI 21.3-30.2) and 18.8 months (95 % CI 16.6-21.7) for patients with low (<14) and high (≥14) ALRI levels, respectively (HR 1.43, 95% CI 1.12-1.82, p=0.004; HR=1.51, 95% CI 1.17-1.96, p<0.001). Interaction tests on ALRI levels and treatment efficacy in the CT+B and the CT groups were statistically significant for PFS (p=0.0003), but not for OS (p=0.228). CONCLUSION: Our results indicate that ALRI is a good prognostic and predictive marker for mCRC patients candidate for CT+B

The ASTAROTH project

The most discussed topic in direct search for dark matter is arguably the verification of the DAMA claim. In fact, the observed annual modulation of the signal rate in an array of NaI(Tl) detectors can be interpreted as the awaited signature of dark matter interaction. Several experimental groups are currently engaged in the attempt to verify such a game-changing claim with the same target material. However, all present-day designs are based on a light readout via Photomultiplier Tubes, whose high noise makes it challenging to achieve a low background in the 1-6 keV energy region of the signal. Even harder it would be to break below 1 keV energy threshold, where a large fraction of the signal potentially awaits to be uncovered. ASTAROTH is an R\&D project to overcome these limitations by using Silicon Photomultipliers (SiPM) matrices to collect scintillation light from NaI(Tl). The all-active design based on cubic crystals is operating in the 87-150 K temperature range where SiPM noise can be even a hundred times lower with respect to PMTs. The cryostat was developed following an innovative design and is based on a copper chamber immersed in a liquid argon bath that can be instrumented as a veto detector. We have characterized separately the crystal and the SiPM response at low temperature and we have proceeded to the first operation of a NaI(Tl) crystal read by SiPM in cryogeny.Comment: proceedings of the LRT 2022 conferenc

Thigh muscles injuries in professional soccer players: a one year longitudinal study

Thigh muscles indirect injuries are common finding in soccer and represent a critical challenge for teams medical staffs. Indirect injuries are classified on the basis of their site and their clinical and radiological findings, but the assessment of a precise prognosis remains a crucial point. Both ultrasound (US) and magnetic resonance (MR) represent effective techniques not only to detect indirect injuries but also to accurately determine severity, location, and, consequently, the prognosis. In this setting, our aim is to review imaging findings of professional athletes muscle tears at three time points (3 days, 2 weeks, and 4 weeks after the time of injury) and, further, to investigate the correlation between tears extent and lay-off time of the athletes. Combined US-MR assessment could be helpful in the management of thigh muscles indirect injuries providing accurate information about the site, the extent, and the healing proces