286 research outputs found
Performance evolution and tensile behaviour of long-term exposed UHPC under sustained load, aggressive environments and autogenous healing
An extended experimental campaign was conducted to analyse the evolution of UHPC tensile performance over time as affected by sustained flexural load and aggressive environments both interacting with its autogenous self-healing capacity. A new methodology including both destructive and non-destructive tests was proposed. Three different mix designs were tested, with steel fibres, crystalline admixture, and various nanomaterials. Specifically, the first batch included alumina nano-fibres, while the second one cellulose nanocrystals. The last one was used as a reference and did not include nanomaterials. Thin beam specimens (500x100x30 mm) were pre-cracked and exposed to three different environments, under four-point bending sustained load. The specimens were cured for 1, 2, 3, 6, 9, and 12 months respectively, being exposed to a chloride solution, geothermal water, and tap water as a reference. After the aforesaid scheduled exposure times, two nominally identical specimens were tested for each condition, the first in four-point bending and the second in direct tension. To compare the results, a simplified five-point inverse analysis was adapted for beams with different slenderness, providing a quadrilinear constitutive law derived from the structural flexural behaviour of four-point bending tests. Test results allowed to highlight the effects of each parameter â type of material and exposure â on the self-healing effectiveness and the tensile response, also defining their evolution over time. The self-healing process resulted in an almost complete recovery after the first two or three months, and the materials were able to maintain a constant performance over longer periods, regardless of the conditions they were exposed to
Historical silks: a novel method to evaluate their condition with ATR-FTIR spectroscopy and Principal Component Analysis
Understanding the conservation condition of historical silk yarn allows to define appropriate storage, care and display of historical silk collections. This paper discusses the characterisation of silk fabrics from a collection of traditional Japanese samurai armours which date back from the 16th to the 20th century (Morigi Collection, Museo delle Culture, Lugano, Switzerland). An analytical protocol to assess silk fabrics conditions was defined, based on microinvasive ATR-FTIR spectroscopy. In particular, the amide I and II region was studied in order to extrapolate the conformational information about silk proteins. According to literature, this kind of information can be related to different degradation stages. A linear correlation was found between the amide I and the amide II shifts, allowing to assess the silk fibre condition. Along with this bivariate approach based on intensity ratios, a multivariate approach based on Principal Component Analysis was also applied to ATR-FTIR spectra. This allowed to group together silks with the same state of preservation. The findings of this research offer a valuable method to researchers and conservators to identify the most damaged textiles; the differentiation between original and restoration materials was also possible in some cases
Intraoperative ĂÂČ-Detecting probe for radio-guided surgery in tumour resection
The development of the ÎČâ based radio-guided surgery aims to extend the technique to those tumours where surgery is the only possible treatment and the assessment of the resection would most profit from the low background around the lesion, as for brain tumours. Feasibility studies on meningioma and gliomas already estimated the potentiality of this new treatment. To validate the technique, a prototype of the intraoperative probe detecting ÎČâ decays and specific phantoms simulating tumour remnant patterns embedded in healthy tissue have been realized. The response of the probe in this simulated environment is tested with dedicated procedures. This document discusses the innovative aspects of the method, the status of the developed intraoperative ÎČâ detecting probe and the results of the preclinical tests
Value of split-bolus multidetector-row CT technique in the quantitative assessment of pancreatic enhancement [Pankreatik tutulumun kantitatif deÄerlendirilmesinde bölĂŒnmĂŒĆ-bolus multidetektör-dizi BT tekniÄinin deÄeri]
The aim of this study is to quantitatively assess radiation comma, and pancreatic enhancement by split-bolus intravenous injection of contrast material using 64-slice CT. Single-pass split-bolus MDCT of the chest and abdomen was performed in 37 patients (female: 18, male: 9; mean age, 66.1ñ14.2 years; range 17-80 years) without pancreatic disease. Regions of interest in the pancreatic head, body and tail were drawn, and mean attenuation values for pancreatic parenchymal phase (PPP) of the standard MDCT protocol and split-bolus were calculated. P<0.05 was considered statistically significant. Mean effective dose by split-bolus was measured. In all MDCT examinations split-bolus protocol allowed acquisition of optimal images. Mean pancreatic enhancement was higher by split-bolus with respect to PPP of standard triphasic MDCT (131.35 HUñ20.63 vs 126.1 HUñ20.01). Reduction of dose using MDCT split-bolus was approximately 17%. In conclusion MDCT split-bolus protocol provides an optimal pancreatic enhancement, significantly greater than the enhancement of standard MDCT on PPP which confers an advantage for the detection and staging of pancreatic tumors
An Intraoperative Detecting Probe For Radio-Guided Surgery in Tumour Resection
The development of the based radio-guided surgery aims to extend
the technique to those tumours where surgery is the only possible treatment and
the assessment of the resection would most profit from the low background
around the lesion, as for brain tumours. Feasibility studies on meningioma,
glioma, and neuroendocrine tumors already estimated the potentiality of this
new treatment. To validate the technique, prototypes of the intraoperative
probe required by the technique to detect radiation have been
developed. This paper discusses the design details of the device and the tests
performed in laboratory. In such tests particular care has to be taken to
reproduce the surgical field conditions. The innovative technique to produce
specific phantoms and the dedicated testing protocols is described in detail.Comment: 7 pages, 15 figure
PROMUOVERE LA COMUNICAZIONE SANITARIA IN UNâOTTICA IAP- CENTRED
The steady promotion of participatory healthcare, from Empowerment policies for cancer patients to Patient-Reported Outcomes (PROs), is acknowledging the patient- citizenâs status as an Individual Active Participant (IAP), thus establishing a new patient-centred era based on the healing power of words. Given the impact of health communication notably in oncology units, this Participatory Action Research project detected and gave expression to both clinical and social needs in favour of female IAPs treated with radiotherapy. The project consisted of group discussions and support initiatives aimed at: (1) spurring self-awareness; (2) fostering health communication; (3) building a community of female IAPs regionwide.La progressiva promozione di prassi sanitarie partecipative, dal Patto per lâEmpowerment del paziente oncologico alla diffusione dei Patient-Reported Outcomes, sta riconoscendo al/la paziente-cittadino/a il suo status di Individuo Attivo e Partecipe (IAP), e sancendo lâingresso della comunitĂ medica e scientifica in una nuova fase patient- centred: quella delle âparole che curanoâ. Dato lâimpatto della comunicazione sanitaria nei reparti oncologici, il presente progetto di Ricerca-Azione Partecipata ha posto al servizio di donne-IAP trattate con radioterapia lâanalisi dei loro bisogni clinici e sociali attraverso gruppi di supporto e discussione tesi a: (1) incentivare autoconsapevolezza; (2) promuovere la comunicazione sanitaria; (3) istituire una comunitĂ di donne-IAP nel territorio pugliese
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