145 research outputs found
Quantitative risk assessment on a hydrogen refuelling station
The Directive 2014/94/UE (DAFI, Alternative Fuel Initiative Directive) on the deployment of alternative fuels (i.e. hydrogen) infrastructures has been recently transposed into national law in Italy. Consequently, the technical regulation on fire prevention for H2fuelling stations has been updated, in order to consider the current maximum delivery pressure (700 bar) of gaseous hydrogen for road vehicles. This technical regulation establishes the prescriptive safety distance from a piece of equipment. In the case of a new station, an assessment of the frequency of the event and its potential consequences is necessary. This is to understand which risk can reasonably be mitigated by a safety distance or whether additional mitigation or prevention measures should be taken. This paper presents the quantitative risk assessment (QRA) study on a hydrogen station planned to be installed, study which aims at determining the safety distances. Such study utilizes the Sandia-developed QRA tool, Hydrogen Risk Analysis Model (HyRAM), to calculate risk values when developing risk-equivalent plans. HyRAM combines reduced order deterministic models that characterize hydrogen release and flame behavior with probabilistic risk models to quantify risk values. Thanks to HyRAM tool it is possible to estimate physical effects and consequences on people and structures and plants, related to risk scenarios, by means of a damage model library. Use of risk assessment may allow station owners and designers to flexibly define station-specific mitigations, with the purpose of achieving equal or better levels of safety with respect to prescriptive recommendation levels, as suggested by ISO19880-1 (2018)
Inventory of Vietri-Maiori landslides induced by the storm of October 1954 (southern Italy)
On 25 October 1954, a storm hit the area surrounding the villages of Vietri sul Mare and Maiori of the Amalfi Coast (southern Italy) causing more than 300 deaths and severe damage to infrastructures and agriculture. This event has been among the most catastrophic historically documented in Campania Region. On this basis, and considering the lack of an existing complete characterization of the event in terms of triggered slope processes, we used multiple sets of stereoscopic aerial photos and a LiDAR-derived high-resolution topography to produce an event landslide inventory map. Our map provides an overview of the landslide distribution and extent in the area that mainly suffered the effect of the storm and is the basis for a morphometric characterization of landslide source areas that we present in this paper as simplified statistical analysis. In addition, we compared the rainfall distribution with the spatial density of source areas
Image convolution: a linear programming approach for filters design
AbstractImage analysis is a branch of signal analysis that focuses on the extraction of meaningful information from images through digital image processing techniques. Convolution is a technique used to enhance specific characteristics of an image, while deconvolution is its inverse process. In this work, we focus on the deconvolution process, defining a new approach to retrieve filters applied in the convolution phase. Given an image I and a filtered image
I
′
=
f
(
I
)
, we propose three mathematical formulations that, starting from I and
I
′
, are able to identify the filter
f
′
that minimizes the mean absolute error between
I
′
and
f
′
(
I
)
. Several tests were performed to investigate the applicability of our approaches in different scenarios. The results highlight that the proposed algorithms are able to identify the filter used in the convolution phase in several cases. Alternatively, the developed approaches can be used to verify whether a specific input image I can be transformed into a sample image
I
′
through a convolution filter while returning the desired filter as output
Metabolomics in Otorhinolaryngology
Otorhinolaryngology (Ear, Nose and Throat-ENT) focuses on inflammatory, immunological, infectious, and neoplastic disorders of the head and neck and on their medical and surgical therapy. The fields of interest of this discipline are the ear, the nose and its paranasal sinuses, the oral cavity, the pharynx, the larynx, and the neck. Besides surgery, there are many other diagnostic aspects of ENT such as audiology and Vestibology, laryngology, phoniatrics, and rhinology. A new advanced technology, named metabolomics, is significantly impacting the field of ENT. All the “omics” sciences, such as genomics, transcriptomics, and proteomics, converge at the level of metabolomics, which is considered the integration of all “omics.” Its application will change the way several of ENT disorders are diagnosed and treated. This review highlights the power of metabolomics, including its pitfalls and promise, and several of its most relevant applications in ENT to provide a basic understanding of the metabolites associated with these districts. In particular, the attention has been focused on different heterogeneous diseases, from head and neck cancer to allergic rhinitis, hearing loss, obstructive sleep apnea, noise trauma, sinusitis, and Meniere’s disease. In conclusion, metabolomics study indicates a “fil rouge” that links these pathologies to improve three aspects of patient care: diagnostics, prognostics, and therapeutics, which in one word is defined as precision medicine
Development of a Novel Device for Decompressive Craniectomy: An Experimental and Cadaveric Study and Preliminary Clinical Application
Background: Decompressive craniectomy is an intervention of established efficacy in patients with intractable cerebral edema.
Objective: To evaluate a new device used in alternative to decompressive craniectomy. This device is designed to perform an augmentative craniotomy by keeping the bone flap elevated using specific cranial suspension titanium plates and giving the brain enough room to swell.
Methods: We tested the mechanical characteristics of the cranial brackets on dried skulls, on 3D-printed skull models, and on a preserved cadaver head. The resistance of the device was examined through dynamometric testing, and the feasibility of the surgical technique, including the suspension of the bone flap and the skin closure, was investigated on the cadaveric model. A preliminary clinical series of 2 patients is also reported.
Results: The laboratory tests have shown that this system allows an adequate expansion of the intracranial volume and it could withstand a force up to 637 ± 13 N in the synthetic model and up to 658 ± 9 N in the human skull without dislocation or failure of the brackets nor fractures of the bone ridges. Preliminary application in the clinical setting has shown that augmentative craniotomy is effective in the control of intracranial hypertension and could reduce the costs and complications associated with the classical decompressive craniectomy technique.
Conclusion: Preliminary laboratory and clinical results show augmentative craniotomy to be a promising, alternative technique to decompressive craniectomy. Further clinical studies will be needed to validate its efficacy
Gut microbiota and polycystic ovary syndrome, focus on genetic associations: a bidirectional Mendelian randomization study
BackgroundThe contribution of gut microbiota to the pathogenesis of polycystic ovary syndrome (PCOS) is controversial. The causal relationship to this question is worth an in-depth comprehensive of known single nucleotide polymorphisms associated with gut microbiota.MethodsWe conducted bidirectional Mendelian randomization (MR) utilizing instrumental variables associated with gut microbiota (N = 18,340) from MiBioGen GWAS to assess their impact on PCOS risk in the FinnGen GWAS (27,943 PCOS cases and 162,936 controls). Two-sample MR using inverse variance weighting (IVW) was undertaken, followed by the weighted median, weighted mode, and MR-Egger regression. In a subsample, we replicated our findings using the meta-analysis PCOS consortium (10,074 cases and 103,164 controls) from European ancestry.ResultsIVWMR results suggested that six gut microbiota were causally associated with PCOS features. After adjusting BMI, SHBG, fasting insulin, testosterone, and alcohol intake frequency, the effect sizes were significantly reduced. Reverse MR analysis revealed that the effects of PCOS features on 13 gut microbiota no longer remained significant after sensitivity analysis and Bonferroni corrections. MR replication analysis was consistent and the results suggest that gut microbiota was likely not an independent cause of PCOS.ConclusionOur findings did not support the causal relationships between the gut microbiota and PCOS features at the genetic level. More comprehensive genome-wide association studies of the gut microbiota and PCOS are warranted to confirm their genetic relationship.DeclarationThis study contains 3533 words, 0 tables, and six figures in the text as well as night supplementary files and 0 supplementary figures in the Supplementary material
Efficacy and safety of the third-generation chloroethylnitrosourea fotemustine for the treatment of chemorefractory T-cell lymphomas.
Patients with recurring T-cell non-Hodgkin lymphoma (T-NHL) are incurable and candidate for investigational agents. Here, we report on five patients with T-NHL refractory to multiple chemotherapy lines, including in all cases alkylators and gemcitabine, who received the third-generation chloroethylnitrosourea fotemustine at a dose of 120 mg/m(2) every 21 d, up to eight courses. Median actual dose intensity was 79%; toxicity was manageable and mainly hematological. One complete remission, one partial remission, two protracted disease stabilization, and one transient, minor response were achieved. Time to progression ranged from 48 to 240+ d. This is the first evidence ever reporting the activity of fotemustine in end-stage T-NHL. Formal studies with this agent are warranted in T-cell malignancies
Red blood cell distribution width in pregnancy: a systematic review
Anisocytosis has been associated with the severity and prognosis of several acute and chronic diseases, as well as physiological conditions such
as pregnancy. Anisocytosis is quantified by the red blood cell distribution width (RDW), expressed as the ratio, multiplied by 100, between the
standard deviation (SD) of red blood cell volumes and the mean corpuscular volume, or as the SD of erythrocyte volumes (RDW-SD). The aim of the
present review was to report the state of the art on the physiological values and the putative diagnostic and prognostic roles of RDW in complicated
pregnancy. Literature research for articles published in the last ten years was conducted in Pubmed, Web of Science, ClinicalTrials.gov, and Scopus
databases. Abstracts were independently screened by two investigators. If relevant, full articles were retrieved. References, in these articles, citing
relevant reviews or original studies were also accessed to identify additional eligible studies. Any disagreement between the reviewers was resolved
by a third investigator. A total of 28 studies were included in the review. These studies reported changes in RDW values during physiological
pregnancy, and associations between the RDW and several pregnancy complications including anaemia, preeclampsia, gestational diabetes, and
recurrent miscarriage. This review provides background information for establishing physiological and pathological RDW values in pregnancy for
diagnostic and prognostic use in clinical practice
Cyclophosphamide Pulse Therapy after Natalizumab Discontinuation for Multiple Sclerosis: a multicenter study.
The still under-investigated role of cognitive deficits in PML diagnosis
Background: Despite cognitive deficits frequently represent the first clinical manifestations of Progressive Multifocal Leukoencephalopathy (PML) in Natalizumab-treated MS patients, the importance of cognitive deficits in PML diagnosis is still under-investigated. The aim of the current study is to investigate the cognitive deficits at PML diagnosis in a group of Italian patients with PML. Methods: Thirty-four PML patients were included in the study. The demographic and clinical data, the lesion load and localization, and the longitudinal clinical course was compared between patients with (n = 13) and without (n = 15) cognitive deficit upon PML suspicion (the remaining six patients were asymptomatic). Clinical presentation of cognitive symptoms was described in detail. Result: After symptoms detection, the time to diagnosis resulted to be shorter for patients presenting with cognitive than for patients with non cognitive onset (p = 0.03). Within patients with cognitive onset, six patients were presenting with language and/or reading difficulties (46.15%); five patients with memory difficulties (38.4%); three patients with apraxia (23.1%); two patients with disorientation (15.3%); two patients with neglect (15.3%); one patients with object agnosia (7.7%), one patient with perseveration (7.7%) and one patient with dementia (7.7%). Frontal lesions were less frequent (p = 0.03), whereas temporal lesions were slightly more frequent (p = 0.06) in patients with cognitive deficits. The longitudinal PML course seemed to be more severe in cognitive than in non cognitive patients (F = 2.73, p = 0.03), but differences disappeared (F = 1.24, p = 0.29) when balancing for the incidence of immune reconstitution syndrome and for other treatments for PML (steroids, plasma exchange (PLEX) and other therapies (Mefloquine, Mirtazapine, Maraviroc). Conclusion: Cognitive deficits at PML onset manifest with symptoms which are absolutely rare in MS. Their appearance in MS patients should strongly suggest PML. Clinicians should be sensitive to the importance of formal neuropsychological evaluation, with particular focus on executive function, which are not easily detected without a formal assessment
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