291 research outputs found
Le conoscenze in FĂsica all'inizio dei corsi universitari in Italia
The article reports the results of an investigation on Italian university students concerning physics knowledge related to common sense schemes at the beginning of the university courses. The results of the diagnosis were communicated both to the students and to the teachers of the courses. The communication enabled the teachers, in the didactical practice, to pinpoint and discuss with the students the discrepancies between the scientific newtonian scheme and common sense scheme. A posttest, given at the end of the course, gives the indication that this practice is effective in inducing a change in the students ideas, notwithstanding the fact that no complete understanding of the scientific viewpoint is teached by the majority of students
Enhance local communities through Design: a holistic approach to regenerate rural environments
The advent of the technological revolution and the current aspiration to reconnect with the land define possibilities for thinking new connections between individuals and communities. These relations are geared towards developing regenerative endeavors and methods, ultimately leading to the establishment of collective well-being. Within rural environments,
there is a propensity to develop strategies that include substantial lifestyle changes. These strategies operate employing practices and actions that, through co-design, aim to revitalize the local area. Through different approaches, the concepts of value and trust are nurtured, facilitating collaborative design of possible futures and transitional pathways to them. The objective of this study is to introduce a theoretical framework that encompasses the distinctive methodologies and actions inherent to the realm of design. This framework is
intended to become a guide for implementing inventive processes, with the goal of revitalizing areas that are struggling with both social neglect and environmental deterioration. The activities conducted until now increased the experiences of relations with communities of place, creating meaningful opportunities, but also highlighting limitations and difficulties in intercommunity relations
Experimental assessment on exploiting low carbon ethanol fuel in a light-duty dual-fuel compression ignition engine
Compression ignition (CI) engines are widely used in modern society, but they are also recognized as a significative source of harmful and human hazard emissions such as particulate matter (PM) and nitrogen oxides (NOx). Moreover, the combustion of fossil fuels is related to the growing amount of greenhouse gas (GHG) emissions, such as carbon dioxide (CO2). Stringent emission regulatory programs, the transition to cleaner and more advanced powertrains and the use of lower carbon fuels are driving forces for the improvement of diesel engines in terms of overall efficiency and engine-out emissions. Ethanol, a light alcohol and lower carbon fuel, is a promising alternative fuel applicable in the dual-fuel (DF) combustion mode to mitigate CO2 and also engine-out PM emissions. In this context, this work aims to assess the maximum fuel substitution ratio (FSR) and the impact on CO2 and PM emissions of different nozzle holes number injectors, 7 and 9, in the DF operating mode. The analysis was conducted within engine working constraints and considered the influence on maximum FSR of calibration parameters, such as combustion phasing, rail pressure, injection pattern and exhaust gas recirculation (EGR). The experimental tests were carried out on a single-cylinder light-duty CI engine with ethanol introduced via port fuel injection (PFI) and direct injection of diesel in two operating points, 1500 and 2000 rpm and at 5 and 8 bar of brake mean effective pressure (BMEP), respectively. Noise and the coefficient of variation in indicated mean effective pressure (COVIMEP) limits have been chosen as practical constraints. In particular, the experimental analysis assesses for each parameter or their combination the highest ethanol fraction that can be injected. To discriminate the effect on ethanol fraction and the combustion process of each parameter, a one-at-a-time-factor approach was used. The results show that, in both operating points, the EGR reduces the maximum ethanol fraction injectable; nevertheless, the ethanol addition leads to outstanding improvement in terms of engine-out PM. The adoption of a 9 hole diesel injector, for lower load, allows reaching a higher fraction of ethanol in all test conditions with an improvement in combustion noise, on average 3 dBA, while near-zero PM emissions and a reduction can be noticed, on the average of 1 g/kWh, and CO2 compared with the fewer nozzle holes case. Increasing the load insensitivity to different holes number was observed
Predictors of lymphocyte count recovery after dimethyl fumarate-induced lymphopenia in people with multiple sclerosis
Background: Dimethyl fumarate (DMF) is an oral drug approved for Relapsing Multiple Sclerosis (RMS) patients. Grade III lymphopenia is reported in 5–10% DMF-treated patients. Data on lymphocyte count (ALC) recovery after DMF withdrawal following prolonged lymphopenia are still scarce. Objectives: To characterize ALC recovery and to identify predictors of slower recovery after DMF interruption. Methods: Multicenter data from RMS patients who started DMF and developed lymphopenia during treatment were collected. In patients with grade II–III lymphopenia, ALCs were evaluated from DMF withdrawal until reaching lymphocyte counts > 800/mm3. Results: Among 1034 patients who started DMF, we found 198 (19.1%) patients with lymphopenia and 65 patients (6.3%) who discontinued DMF due to persistent grade II–III lymphopenia. Complete data were available for 51 patients. All patients recovered to ALC > 800 cells/mm3 with a median time of 3.4 months. Lower ALCs at DMF suspension (HR 0.98; p = 0.005), longer disease duration (HR 1.29; p = 0.014) and prior exposure to MS treatments (HR 0.03; p = 0.025) were found predictive of delayed ALC recovery. Conclusion: ALC recovery after DMF withdrawal is usually rapid, nevertheless it may require longer time in patients with lower ALC count at DMF interruption, longer disease duration and previous exposure to MS treatments, potentially leading to delayed initiation of a new therapy
Pregnancy effect on disease activity in women with multiple sclerosis treated with cladribine
Introduction Cladribine is an oral immune reconstitution therapy for relapsing multiple sclerosis (RMS). Hormonal and immune changes are responsible for the decline of disease activity in the third trimester of pregnancy and disease reactivation in the early post-partum period.We investigate the impact of pregnancy on disease activity in women with MS who conceived after cladribine treatment.Methods We recruited women of childbearing age with relapsing-remitting MS (RRMS) who became pregnant or not after being treated with cladribine. For both groups, demographic, clinical and radiological data were collected 1 year before and after treatment during a mean follow-up of 3.53 years. We compared disease activity over time between groups using variance analysis for repeated measures.Results 48 childbearing women were included. 25 women had a pregnancy after a mean of 1.75 years from the first treatment cycle. Women with or without pregnancy did not differ in demographics or pre-cladribine disease activity. No significant differences in disease activity or EDSS worsening were found between women with or without pregnancy.Discussion Our findings suggest that pregnancy does not appear to influence disease activity and disability in women previously treated with cladribine; further studies with larger numbers and longer follow-up are needed to confirm this finding
Gemcitabine plus vinorelbine in advanced non-small cell lung cancer: a phase II study of three different doses
Our aim was to study the activity and toxicity of the gemcitabine plus vinorelbine (Gem Vin) combination and to identify the optimal dose. Previously untreated patients aged < 70 years, with stage IV or IIIb (not candidates for radiotherapy) non-small cell lung cancer were eligible. Studied dose-levels of Gem Vin, administered on days 1 and 8 every 3 weeks, were (mg m–2): level I = 1000/25; level II = 1200/25; level III = 1000/30; level IV = 1200/30. A feasibility study was performed at each dose-level, followed by a single-stage phase II study. Dose-level IV was unfeasible because of grade 4 neutropenia. Overall, out of 126 patients enrolled in phase II studies, there were one complete and 32 partial responses (response rate 26%: 95% CI 18–34%). Response rates were 27.9%, 21.4% and 29.3% at levels I, II and III, respectively. The treatment was well tolerated. Toxicity was less frequent and severe at level I. Overall median survival was 33 weeks (95% CI 28–40). Descriptive quality of life analysis showed that patients with a worse baseline global health status score tended to drop out of the study earlier than those with a better score. Gem Vin is feasible at different doses. It is sufficiently active and well tolerated. A phase III study to compare the effect on quality of life of Gem Vin (level I) vs cisplatin-based chemotherapy is ongoing. © 2000 Cancer Research Campaig
Blockade of EIF5A hypusination limits colorectal cancer growth by inhibiting MYC elongation
Eukaryotic Translation Initiation Factor 5A (EIF5A) is a translation factor regulated by hypusination, a unique posttranslational modification catalyzed by deoxyhypusine synthetase (DHPS) and deoxyhypusine hydroxylase (DOHH) starting from the polyamine spermidine. Emerging data are showing that hypusinated EIF5A regulates key cellular processes such as autophagy, senescence, polyamine homeostasis, energy metabolism, and plays a role in cancer. However, the effects of EIF5A inhibition in preclinical cancer models, the mechanism of action, and specific translational targets are still poorly understood. We show here that hypusinated EIF5A promotes growth of colorectal cancer (CRC) cells by directly regulating MYC biosynthesis at specific pausing motifs. Inhibition of EIF5A hypusination with the DHPS inhibitor GC7 or through lentiviral-mediated knockdown of DHPS or EIF5A reduces the growth of various CRC cells. Multiplex gene expression analysis reveals that inhibition of hypusination impairs the expression of transcripts regulated by MYC, suggesting the involvement of this oncogene in the observed effect. Indeed, we demonstrate that EIF5A regulates MYC elongation without affecting its mRNA content or protein stability, by alleviating ribosome stalling at five distinct pausing motifs in MYC CDS. Of note, we show that blockade of the hypusination axis elicits a remarkable growth inhibitory effect in preclinical models of CRC and significantly reduces the size of polyps in APCMin/+ mice, a model of human familial adenomatous polyposis (FAP). Together, these data illustrate an unprecedented mechanism, whereby the tumor-promoting properties of hypusinated EIF5A are linked to its ability to regulate MYC elongation and provide a rationale for the use of DHPS/EIF5A inhibitors in CRC therapy
- …