588 research outputs found
Extensive reuse of soda-lime waste glass in fly ash-based geopolymers
The possibility of extensive incorporation of soda-lime waste glass in the synthesis of fly ash-based geopolymers was investigated. Using waste glass as silica supplier avoids the use of water glass solution as chemical activator. The influence of the addition of waste glass on the microstructure and strength of fly ash-based geopolymers was studied through microstructural and mechanical characterization. Leaching analyses were also carried out. The samples were developed changing the SiO2/Al2O3 molar ratio and the molarity of the sodium hydroxide solution used as alkaline activator. The results suggest that increasing the amount of waste glass as well as increasing the molarity of the solution lead to the formation of zeolite crystalline phases and an improvement of the mechanical strength. Leaching results confirmed that the new geopolymers have the capability to immobilize heavy metal ions
Galactic Outflows and the pollution of the Galactic Environment by Supernovae
We here explore the effects of the SN explosions into the environment of
star-forming galaxies like the Milky Way. Successive randomly distributed and
clustered SNe explosions cause the formation of hot superbubbles that drive
either fountains or galactic winds above the galactic disk, depending on the
amount and concentration of energy that is injected by the SNe. In a galactic
fountain, the ejected gas is re-captured by the gravitational potential and
falls back onto the disk. From 3D nonequilibrium radiative cooling
hydrodynamical simulations of these fountains, we find that they may reach
altitudes up to about 5 kpc in the halo and thus allow for the formation of the
so called intermediate-velocity-clouds (IVCs) which are often observed in the
halos of disk galaxies. The high-velocity-clouds that are also observed but at
higher altitudes (of up to 12 kpc) require another mechanism to explain their
production. We argue that they could be formed either by the capture of gas
from the intergalactic medium and/or by the action of magnetic fields that are
carried to the halo with the gas in the fountains. Due to angular momentum
losses to the halo, we find that the fountain material falls back to smaller
radii and is not largely spread over the galactic disk. Instead, the SNe ejecta
fall nearby the region where the fountain was produced, a result which is
consistent with recent chemical models of the galaxy. The fall back material
leads to the formation of new generations of molecular clouds and to supersonic
turbulence feedback in the disk.Comment: 10 pages, 5 figures; paper of invited talk for the Procs. of the 2007
WISER Workshop (World Space Environment Forum), Alexandria, Egypt, October
2007, Spa. Sci. Rev
A new taxon in the Infundibulicybe gibba complex (Basidiomycota, Agaricales, Tricholomataceae) from Sardinia (Italy)
Symptom Perceptions and Self-care Behaviors in Patients Who Self-manage Heart Failure
Background: Patients with heart failure (HF) are at heightened risk for acute exacerbation requiring hospitalization. Although timely reporting of symptoms can expedite outpatient treatment and avoid the need for hospitalization, few patients recognize and respond to symptoms until acutely ill.
Objective: The purpose of this study was to explore patients’ perceptions of symptoms and self-care behaviors for symptom relief, leading up to a HF hospitalization. Methods: To examine prehospitalization symptom scenarios, semistructured interviews were conducted with 60 patients hospitalized for acute decompensated HF. Results: Thirty-seven patients (61.7%) said that they had a sense that “something just wasn’t quite right” before their symptoms began but were unable to specify further. Signs and symptoms most often recognized by the patients were related to dyspnea (85%), fatigue (53.3%), and edema (41.7%). Few patients interpreted their symptoms as being related to worsening HF and most often attributed symptoms to changes in diet (18.3%) and medications (13.3%). Twenty-six patients (43.3%) used self-care strategies to relieve symptoms before hospital admission. More than 40% of the patients had symptoms at least 2 weeks before hospitalization. Conclusions: Despite the wide dissemination of HF evidence-based guidelines, important components of symptom self-management remain suboptimal. Because most of HF self-management occurs in the postdischarge environment, research is needed that identifies how patients interpret symptoms of HF in the specific contexts in which patients self-manage their HF. These findings suggest the need for interventions that will help patients expeditiously recognize, accurately interpret, and use appropriate and safe self-care strategies for symptoms
Paxillus orientalis sp. nov. (Paxillaceae, Boletales) from south-western China based on morphological and molecular data and proposal of the new subgenus Alnopaxillus
DNA vaccines against ErbB2+ Carcinomas: From mice to humans.
DNA vaccination exploits a relatively simple and flexible technique to generate
an immune response against microbial and tumor-associated antigens (TAAs). Its
effectiveness is enhanced by the application of an electrical shock in the area of plasmid
injection (electroporation). In our studies we exploited a sophisticated electroporation
device approved for clinical use (Cliniporator, IGEA, Carpi, Italy). As the target antigen is
an additional factor that dramatically modulates the efficacy of a vaccine, we selected
ErbB2 receptor as a target since it is an ideal oncoantigen. It is overexpressed on the cell
membrane by several carcinomas for which it plays an essential role in driving their
progression. Most oncoantigens are self-tolerated molecules. To circumvent immune
tolerance we generated two plasmids (RHuT and HuRT) coding for chimeric rat/human
ErbB2 proteins. Their immunogenicity was compared in wild type mice naturally tolerant
for mouse ErbB2, and in transgenic mice that are also tolerant for rat or human ErbB2. In
several of these mice, RHuT and HuRT elicited a stronger anti-tumor response than
plasmids coding for fully human or fully rat ErbB2. The ability of heterologous moiety to
blunt immune tolerance could be exploited to elicit a significant immune response in patients. A clinical trial to delay the recurrence of ErbB2+ carcinomas of the oral cavity,
oropharynx and hypopharynx is awaiting the approval of the Italian authorities
On the variability of spore-ornamentation in Laccaria tortilis (Basidiomycota, Agaricomycetes)
Detection of lithium plating in li-ion cell anodes using realistic automotive fast-charge profiles
The widespread use of electric vehicles is nowadays limited by the “range anxiety” of the customers. The drivers’ main concerns are related to the kilometric range of the vehicle and to the charging time. An optimized fast-charge profile can help to decrease the charging time, without degrading the cell performance and reducing the cycle life. One of the main reasons for battery capacity fade is linked to the Lithium plating phenomenon. This work investigates two methodologies, i.e., three-electrode cell measurement and internal resistance evolution during charging, for detecting the Lithium plating conditions. From this preliminary analysis, it was possible to develop new Multi-Stage Constant-Current profiles, designed to improve the performance in terms of charging time and cells capacity retention with respect to a reference profile. Four new profiles were tested and compared to a reference. The results coming from the new profiles demonstrate a simultaneous improvement in terms of charging time and cycling life, showing the reliability of the implemented methodology in preventing Lithium plating
Recommended from our members
Pulmonary embolism following complex trauma: UK MTC observational study.
OBJECTIVES: To describe the incidence of pulmonary embolism (PE) in a critically ill UK major trauma centre (MTC) patient cohort. METHODS: A retrospective, multidataset descriptive study of all trauma patients requiring admission to level 2 or 3 care in the East of England MTC from 1 November 2014 to 1 May 2017. Data describing demographics, the nature and extent of injuries, process of care, timing of PE prophylaxis, tranexamic acid (TXA) administration and CT scanner type were extracted from the Trauma Audit and Research Network database and hospital electronic records. PE presentation was categorised as immediate (diagnosed on initial trauma scan), early (within 72 hours of admission but not present initially) and late (diagnosed after 72 hours). RESULTS: Of the 2746 trauma patients, 1039 were identified as being admitted to level 2 or 3 care. Forty-eight patients (4.6%) were diagnosed with PE during admission with 14 immediate PEs (1.3%). Of 32.1% patients given TXA, 6.3% developed PE compared with 3.8% without TXA (p=0.08). CONCLUSION: This is the largest study of the incidence of PE in UK MTC patients and describes the greatest number of immediate PEs in a civilian complex trauma population to date. Immediate PEs are a rare phenomenon whose clinical importance remains unclear. Tranexamic acid was not significantly associated with an increase in PE in this population following its introduction into the UK trauma care system
- …