Validation of an Emission Model for a Marine Diesel Engine with Data from Sea Operations

In this study, a model is developed to simulate the dynamics of an internal combustion engine, and it is calibrated and validated against reliable experimental data, making it a tool that can effectively be adopted to conduct emission predictions. In this work, the Ricardo WAVE software is applied to the simulation of a particular marine diesel engine, a four-stroke engine used in the maritime field. Results from the bench tests are used for the calibration of the model. Finally, the calibration of the model and its validation with full-scale data measured at sea are presented. The prediction includes not only the classic engine operating parameters for a comparison with surveys but also an estimate of nitrogen oxide emissions, which are compared with similar results obtained with emission factors. The calibration of the model made it possible to obtain an overlap between the simulation results and real data with an average error of approximately 7% on power, torque, and consumption. The model provides encouraging results, suggesting further applications, such as in the study on transient conditions, coupling of the engine model with the ship model for a complete simulation of the operating conditions, and optimization studies on consumption and emissions. The availability of the emission data during the sea trial and validated simulation results are the strengths and novelties of this work

Proline-Functionalised Calix[4]arene: An Anion-Triggered Hydrogelator

A water-soluble, chiral calix[4]arene has been found to form hydrogels when triggered by the presence of specific anions, with efficacy linked to the Hofmeister series; the gel properties are modified by the associated cations, and gelation can be reversibly switched off by increasing pH

Therapeutic sequences in patients with grade 1−2 neuroendocrine tumors (NET): an observational multicenter study from the ELIOS group

Purpose: Many different treatments are suggested by guidelines to treat grade 1−2 (G1−G2) neuroendocrine tumors (NET). However, a precise therapeutic algorithm has not yet been established. This study aims at identifying and comparing the main therapeutic sequences in G1−G2 NET. Methods: A retrospective observational Italian multicenter study was designed to collect data on therapeutic sequences in NET. Median progression-free survival (PFS) was compared between therapeutic sequences, as well as the number and grade of side effects and the rate of dose reduction/treatment discontinuation. Results: Among 1182 patients with neuroendocrine neoplasia included in the ELIOS database, 131 G1–G2 gastroenteropancreatic, lung and unknown primary NET, unresectable or persistent/relapsing after surgery, treated with ≥2 systemic treatments, were included. Four main therapeutic sequences were identified in 99 patients: (A) somatostatin analogs (SSA) standard dose to SSA high dose (n = 36), (B) SSA to everolimus (n = 31), (C) SSA to chemotherapy (n = 17), (D) SSA to peptide receptor radionuclide therapy (PRRT) (n = 15). Median PFS of the second-line treatment was not reached in sequence A, 33 months in sequence B, 20 months in sequence C, 30 months in sequence D (p = 0.16). Both total number and severity of side effects were significantly higher in sequences B and C than A and D (p = 0.04), as well as the rate of dose reduction/discontinuation (p = 0.03). Conclusions: SSA followed by SSA high dose, everolimus, chemotherapy or PRRT represent the main therapeutic sequences in G1−G2 NET. Median PFS was not significantly different between sequences. However, the sequences with SSA high dose or PRRT seem to be better tolerated than sequences with everolimus or chemotherapy

Thermal annealing behaviour and gel to crystal transition of a low molecular weight hydrogelator

The thermal annealing behaviour of an electrolyte-triggered calixarene hydrogelator is found to depend strongly on the specific metal chloride used. While the lithium chloride gel showed typical gel-sol transitions as a function of temperature, the magnesium chloride gel was found to repeatedly strengthen with heat-cool cycles. Structural investigations using small-angle neutron scattering, and scanning probe microscopy, suggest that the annealing behaviour is associated with a change in morphology of the fibrous structures supporting the gel. On prolonged standing at room temperature, the magnesium chloride gel underwent a gel-crystal transition, with the collapsing gel accompanied by the deposition of crystals of a magnesium complex of the proline-functionalised calix[4]arene gelator

Diverse approaches to learning with immersive Virtual Reality identified from a systematic review

To investigate how learning in immersive Virtual Reality was designed in contemporary educational studies, this systematic literature review identified nine design features and analysed 219 empirical studies on the designs of learning activities with immersive Virtual Reality. Overall, the technological features for physical presence were more readily implemented and investigated than pedagogical features for learning engagement. Further analysis with k-means clustering revealed five approaches with varying levels of interactivity and openness in learning tasks, from watching virtual worlds passively to responding to personalised prompts. Such differences in the design appeared to stem from different practical and educational priorities, such as accessibility, interactivity, and engagement. This review highlights the diversity in the learning task designs in immersive Virtual Reality and illustrates how researchers are navigating practical and educational concerns. We recommend future empirical studies recognise the different approaches and priorities when designing and evaluating learning with immersive Virtual Reality. We also recommend that future systematic reviews investigate immersive Virtual Reality-based learning not only by learning topics or learner demographics, but also by task designs and learning experiences

Diverse approaches to learning with immersive Virtual Reality identified from a systematic review

To investigate how learning in immersive Virtual Reality was designed in contemporary educational studies, this systematic literature review identified nine design features and analysed 219 empirical studies on the designs of learning activities with immersive Virtual Reality. Overall, the technological features for physical presence were more readily implemented and investigated than pedagogical features for learning engagement. Further analysis with k-means clustering revealed five approaches with varying levels of interactivity and openness in learning tasks, from watching virtual worlds passively to responding to personalised prompts. Such differences in the design appeared to stem from different practical and educational priorities, such as accessibility, interactivity, and engagement. This review highlights the diversity in the learning task designs in immersive Virtual Reality and illustrates how researchers are navigating practical and educational concerns. We recommend future empirical studies recognise the different approaches and priorities when designing and evaluating learning with immersive Virtual Reality. We also recommend that future systematic reviews investigate immersive Virtual Reality-based learning not only by learning topics or learner demographics, but also by task designs and learning experiences

One-pot Selective Formylation and Claisen Rearrangement on Calix[4]arenes

A versatile synthon with formyl and allyl groups at the upper rim of calix[4]arene has been synthesized in two steps. Selective formylation of 25,27-diallyloxy-26,28-dihydroxycalix[4]arene, along with the Claisen rearrangement of the allyl groups, was achieved by reaction with hexamethylenetetraamine (hexamine) in glacial acetic acid. A control reaction of the dipropyl analogue shows that the selective formylation takes place independently of the Claisen rearrangement. The crystal structure of the dimethylacetal derivative of 5,17-diformyl-11,23-diallylcalix[4]arene is reported

Partial functionalisation of C4-symmetric tetramethoxyresorcinarenes

© 2019 Informa UK Limited, trading as Taylor & Francis Group. Investigations into the distal-functionalisation of the phenols of racemic C4-symmetric tetramethoxyresorcinarene has led to a simple, single-step procedure that allows the isolation of gram quantities of partially silylated derivatives, with the targeted distally silylated resorcinarene being obtained in a yield of 31%. These partially silylated derivatives would serve as versatile intermediates for the selective functionalisation of this elegant architecture. The solid-state structures of many of these derivatives have been determined by single crystal X-ray crystallography

TOLERABILITYAND QUALITY OF LIFE IN ELDERLY PATIENTS TREATEDWITH BEVACIZUMAB FOR METASTATIC COLORECTAL CANCER

monoclonal antibody, in combination with regimens based on 5FU/LV (or capecitabine) ± irinotecan or oxaliplatin, considerably improved prognosis of patients with metastatic colorectal cancer (mCRC). However, potential adverse events such as hypertension, proteinuria, bleeding, gastrointestinal perforation and thrombosis should be considered especially in elderly patients. Aim of our study was to assess bevacizumab-related adverse events and their influence on quality of life in two groups of patients with mCRC. Patients and methods. From January 2008 to June 2010 we studied 59 patients with mCRC, receiving first-line chemotherapy plus bevacizumab (5 mg/kg every 2 weeks), divided in two groups, the first of 28 patients aged ≤70 years (range 35-70; mean 58.4 years) and the second of 31 patients >70 years (range 71-79; mean 72.7 years). Patients with impaired renal function and/or proteinuria ≥0.5 g/day were excluded. Adverse events were defined according to the National Cancer Institute Common Terminology Criteria (NCI-CTCAE v3.0.) Quality of life was assessed with FACT-C, EORTC-C30 and CR38 questionnaires. Patients were evaluated at baseline, at each cycle of therapy, three and six months after the end of chemotherapy. Results. Any grade hypertension occurred in 7 (25%) patients ≤70 years and in 9 (29%) older patients. Grade 3 hypertension, requiring the initiation or a change of antihypertensive therapy, was observed in 3 (10.7%) patients ≤70 years and in 4 (12.9%) patients >70 years. Proteinuria occurred in 8 (28.6%) patients ≤70 years and in 9 (29%) older patients. Grade 4 hypertension (hypertensive crisis) and/or grade 4 proteinuria (nephrotic syndrome) was not seen. The FACT-C and EORTC questionnaires showed that bevacizumab-related side effects had no impact on quality of life. Conclusion. In our study combination therapy with bevacizumab was well tolerated with a generally manageable safety profile in all patients. Bevacizumab-related adverse events such as hypertension and proteinuria, while noting more prevalent in patients aged >70 years, had no significant effects on quality of life