Air/methane mixture ignition with Multi-Walled Carbon Nanotubes (MWCNTs) and comparison with spark ignition

The possibility to ignite the single wall carbon nanotubes (SWCNTs) containing impurities of iron in atmosphere once exposed to the radiation of a flash camera was observed for the first time in 2002. Afterwards, it was proposed to exploit this property in order to use nanostructured materials as ignition agents for fuel mixtures. Finally, in 2011 it was shown that SWCNTs can be effectively used as ignition source for an air/ethylene mixture filling a constant volume combustion chamber; the observed combustion presented the characteristics of a homogeneous-like combustion. In this paper a system for the ignition of an air/methane mixture is proposed, based on the exposition of multi wall carbon nanotubes (MWCNTs) to a low consumption flash camera. Namely, several experiments have been run in which 20 mg of MWCNTs, containing 75% in weight of ferrocene, have been added to an air/methane fuel mixture inside a constant volume combustion chamber. The mixture has been heated up to 373 K and the onset pressure was set equal to 3 bar. The experiments have been run varying the equivalence ratio in the range 1–2. The combustion process so realized has been compared to that obtained igniting the mixture with a traditional spark as in spark ignition engines. The comparison has been based on chamber pressure measurement as well as combustion process images, both sampled at a frequency equal to 2,5 kHz for an overall duration of 1.8 s. Results confirm that the ignition triggered with MWCNTs leads to a homogeneous-like combustion, without observing a well-defined flame front propagation. The contrary is observed, as expected, with the spark assisted ignition. Moreover, dynamic pressure measurements show that, compared to spark assisted ignition, the MWCNTs photo-ignition determines a more rapid pressure gradient and a higher peak pressure which corresponds to a higher energy release rate

Properties of Nanocrystals-formulated Aluminosilicate Bricks

In the present work, seven different types of nanocrystals were studied as additives in the formulation of aluminosilicate bricks. The considered nanocrystals consisted of anatase titanium dioxide (two differently shaped types), boron modified anatase, calcium carbonate (in calcite phase), aluminium hydroxide and silicon carbide (of two diverse sizes), which were prepared using different methods. Syntheses aim to give a good control over a particle’s size and shape. Anatase titania nanocrystals, together with the nano-aluminium hydroxide ones, were synthesized via microwave-assisted procedures, with the use of different additives and without the final calcination steps. The silicon carbide nanoparticles were prepared via laser pyrolysis. The nano-calcium carbonate was prepared via a spray drying technique. All of the nanocrystals were tested as fillers (in 0.5, 1 and 2 wt. % amounts) in a commercial aluminosilicate refractory (55 % Al2O3, 42 % SiO2). They were used to prepare bricks that were thermally treated at 1300 °C for 24 hours, according to the international norms. The differently synthesized nanocrystals were added for the preparation of the bricks, with the aim to improve their heat-insulating and/or mechanical properties. The nanocrystals-modified refractories showed variations in properties, with respect to the untreated aluminosilicate reference in heat-insulating performances (thermal diffusivities were measured by the “hot disk” technique). In general, they also showed improvements in mechanical compression resistance for all of the samples at 2 wt. %. The best heat insulation was obtained with the addition of nano-aluminium hydroxide at 2 wt. %, while the highest mechanical compression breaking resistance was found with nano-CaCO3 at 2 wt. %. These outcomes were investigated with complementary techniques, like mercury porosimetry for porosity, and Archimedes methods to measure physical properties like the bulk and apparent densities, apparent porosities and water absorption. The results show that the nano-aluminium hydroxide modified bricks were the most porous, which could explain the best heat-insulating performances. There is a less straightforward explanation for the mechanical resistance results, as they may have relations with the characteristics of the pores. Furthermore, the nanoparticles may have possible reactions with the matrix during the heat treatments

Changes in ceftriaxone pharmacokinetics/pharmacodynamics during the early phase of sepsis: a prospective, experimental study in the rat

Abstract Background Sepsis is characterized by the loss of the perm-selectivity properties of the glomerular filtration barrier (GFB) with consequent albuminuria. We examined whether the pharmacokinetics–pharmacodynamics (PK/PD) of ceftriaxone (CTX), an extensively protein-bound 3rd generation cephalosporin, is altered during early sepsis and whether an increase in urinary loss of bound-CTX, due to GFB alteration, can occur in this condition. Methods A prospective, experimental, randomized study was carried out in adult male Sprague–Dawley rats. Sepsis was induced by cecal ligation and puncture (CLP). Rats were divided into two groups: Sham-operated and CLP. CTX (100 mg i.p., equivalent to 1 g dose in humans) was administered in order to measure plasma and lung CTX concentrations at several time-points: baseline and 1, 2, 4 and 6 h after administration. CTX was measured by High Performance Liquid Chromatography (HPLC). The morphological status of the sialic components of the GFB barrier was assessed by lectin histo-chemistry. Monte Carlo simulation was performed to calculate the probability of target attainment (PTA >90%) for 80 and 100% of Tfree > minimum inhibitory concentration (MIC) for 80 and 100% of dosing interval. Measurements and main results After CLP, sepsis developed in rats as documented by the growth of polymicrobial flora in the peritoneal fluid (≤1 × 101 CFU in sham rats vs 5 × 104–1 × 105 CFU in CLP rats). CTX plasma concentrations were higher in CLP than in sham rats at 2 and 4 h after administration (difference at 2 h was 47.3, p = 0.012; difference at 4 h was 24.94, p = 0.004), while lung penetration tended to be lower. An increased urinary elimination of protein-bound CTX occurred (553 ± 689 vs 149 ± 128 mg/L, p < 0.05; % of bound/total CTX 22 ± 6 in septic rats vs 11 ± 4 in sham rats, p < 0.01) and it was associated with loss of the GFB sialic components. According to Monte Carlo simulation a PTA > 90% for 100% of the dosing interval was reached neither for sham nor CLP rats using MIC = 1 mg/L, the clinical breakpoint for Enterobacteriacee. Conclusions Sepsis causes changes in the PK of CTX and an alteration in the sialic components of the GFB, with consequent loss of protein-bound CTX. Among factors that can affect drug pharmacokinetics during the early phases of sepsis, urinary loss of both free and albumin–bound antimicrobials should be considered

Indagini geofisiche e geochimiche di un sinkhole in formazione nell’area di Guidonia (Lazio)

The Plio-Quaternary Acque Albule Basin is already known for the occurrence of sinkholes; since the spring 2014, it has been ongoing the study of an active subsidence process, which formed a depressed area near the Guidonia village. During the last year, the phenomenon has become more intense giving rise to two collapses along the eastern rim of the depression. Thus, geophysical and geogeochemical investigation campaigns started in order to understand the genesis and evolution of the phenomenon. Survey results allowed a geological and structural characterization, showing the presence of “travertino” at the depression margins and its absence therein. It has been recognized, by the geophysics, features with NW-SE and NNE-SSW direction ascribable to a possible depression fracturing and consistent with regional structural trends. Thus, it has been possible to plan and perform geognostic investigation consisting in two drillings aimed to define the stratigraphy of the marginal and inner part of the depression.Published7 - 162TR. Ricostruzione e modellazione della struttura crostaleJCR Journa

Prognostic factors of lung cancer in lymphoma survivors (the LuCiLyS study)

Background Second cancer is the leading cause of death in lymphoma survivors, with lung cancer representing the most common solid tumor. Limited information exists about the treatment and prognosis of second lung cancer following lymphoma. Herein, we evaluated the outcome and prognostic factors of Lung Cancer in Lymphoma Survivors (the LuCiLyS study) to improve the patient selection for lung cancer treatment. Methods This is a retrospective multicentre study including consecutive patients treated for lymphoma disease that subsequently developed non-small cell lung cancer (NSCLC). Data regarding lymphoma including age, symptoms, histology, disease stage, treatment received and lymphoma status at the time of lung cancer diagnosis, and data on lung carcinoma as age, smoking history, latency from lymphoma, symptoms, histology, disease stage, treatment received, and survival were evaluated to identify the significant prognostic factors for overall survival. Results Our study population included 164 patients, 145 of which underwent lung cancer resection. The median overall survival was 63 (range, 58–85) months, and the 5-year survival rate 54%. At univariable analysis no-active lymphoma (HR: 2.19; P=0.0152); early lymphoma stage (HR: 1.95; P=0.01); adenocarcinoma histology (HR: 0.59; P=0.0421); early lung cancer stage (HR: 3.18; P&lt;0.0001); incidental diagnosis of lung cancer (HR: 1.71; P&lt;0.0001); and lung cancer resection (HR: 2.79; P&lt;0.0001) were favorable prognostic factors. At multivariable analysis, no-active lymphoma (HR: 2.68; P=0.004); early lung cancer stage (HR: 2.37; P&lt;0.0001); incidental diagnosis of lung cancer (HR: 2.00; P&lt;0.0001); and lung cancer resection (HR: 2.07; P&lt;0.0001) remained favorable prognostic factors. Patients with non-active lymphoma (n=146) versus those with active lymphoma (n=18) at lung cancer diagnosis presented better median survival (64 vs. 37 months; HR: 2.4; P=0.02), but median lung cancer specific survival showed no significant difference (27 vs. 19 months; HR: 0.3; P=0.17). Conclusions The presence and/or a history of lymphoma should not be a contraindication to resection of lung cancer. Inclusion of lymphoma survivors in a lung cancer-screening program may lead to early detection of lung cancer, and improve the survival

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research