47 research outputs found

    Automated biowaste sampling system improved feces collection, mass measurement and sampling

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    The capability of the basic automated Biowaste Sampling System (ABSS) hardware was extended and improved through the design, fabrication and test of breadboard hardware. A preliminary system design effort established the feasibility of integrating the breadboard concepts into the ABSS

    Automated biowaste sampling system urine subsystem operating model, part 1

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    The urine subsystem automatically provides for the collection, volume sensing, and sampling of urine from six subjects during space flight. Verification of the subsystem design was a primary objective of the current effort which was accomplished thru the detail design, fabrication, and verification testing of an operating model of the subsystem

    Urine sampling and collection system

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    This specification defines the performance and design requirements for the urine sampling and collection system engineering model and establishes requirements for its design, development, and test. The model shall provide conceptual verification of a system applicable to manned space flight which will automatically provide for collection, volume sensing, and sampling of urine

    Automated biowaste sampling system, solids subsystem operating model, part 2

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    The detail design and fabrication of the Solids Subsystem were implemented. The system's capacity for the collection, storage or sampling of feces and vomitus from six subjects was tested and verified

    Role of human tissue kallikrein in gastrointestinal stromal tumour invasion

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    Background: Human tissue kallikrein (hK1) generates vasodilator kinins from kininogen and promotes angiogenesis by kinin-dependent and kinin-independent mechanisms. Here, we investigate the expression and functional relevance of hK1 in human gastrointestinal stromal tumour (GIST).<p></p> Methods: Vascularisation and hK1 expression of GIST samples were assessed by immunohistochemistry. In two GIST cell lines, hK1 expression was assessed by PCR, and hK1 protein levels and activity were measured by ELISA and an amidolytic assay, respectively. The effect of hK1 silencing, inhibition or overexpression on GIST cell proliferation, migration and paracrine induction of angiogenesis was studied. Finally, local and systemic levels of hK1 were assessed in mice injected with GIST cells.<p></p> Results: Human tissue kallikrein was detected in 19 out of 22 human GIST samples. Moreover, GIST cells express and secrete active hK1. Titration of hK1 demonstrated its involvement in GIST invasive behaviour, but not proliferation. Furthermore, hK1 released by GIST cells promoted endothelial cell migration and network formation through kinin-dependent mechanisms. Gastrointestinal stromal tumour implantation in nude mice resulted in local and systemic hK1 expression proportional to tumour dimension.<p></p> Conclusions: Human tissue kallikrein is produced and released by GIST and participates in tumour invasion. Further studies are needed to validate hK1 as a diagnostic biomarker and therapeutic target in GIST

    Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy

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    Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86–1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91–1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable. Funding: UK Medical Research Council and Health Technology Assessment Programme

    European multicenter registry for the performance of the chimney/snorkel technique in the treatment of aortic arch pathologic conditions

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    Background To study the performance of the chimney technique in the treatment of aortic arch pathologic conditions. Methods We retrospectively evaluated the clinical and procedural outcome data of patients undergoing endovascular treatment in the aortic arch by use of the chimney technique at four European centers between June 2002 and December 2014. The primary endpoint was technical success. The secondary endpoints were type I endoleak, 30-day mortality, stroke, primary patency of the chimney graft, and freedom from reintervention. Results Ninety-five patients were included in the study. The underlying pathologic conditions were degenerative aneurysm (n = 45, 47.4%), type B aortic dissection (n = 30, 31.6%), dissecting aneurysm (n = 6, 6.5%), penetrating atherosclerotic ulcer (n = 5, 5.3%), type I endoleak after previous thoracic endovascular aortic repair (n = 6, 6.3%), and aortic embolic disease (n = 3, 3.2%). Twenty-one patients (22%) underwent arch-branch debranching before chimney graft implantation. The majority of patients were treated electively (n = 49, 51.6%). Forty-six patients (48.4%) underwent urgent placement of chimney grafts because of their symptoms (n = 25) or rupture (n = 21). Technical success was 89.5%. The 30-day mortality was 9.5% (9 patients). No aorta-related death was observed. A type Ia endoleak occurred in 10 patients (10.5%) intraoperatively, resolving spontaneously within the first 30 days in 50% of these cases. Major stroke was diagnosed in 2 patients (2%). Primary patency of the chimney grafts was 98%, and 5 patients (5.2%) required a reintervention. Conclusions The chimney technique in the aortic arch proved highly and predictably successful, with a low rate of reinterventions

    RILEM TC 258-AAA Round Robin Test: Alkali release from aggregates. Critical review of the test method AAR-8

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    The aim of this work is to introduce the method and modifications proposed by several laboratories after carrying out the Round Robin Test based on the AAR-8 method “Determination of alkalis releasable by aggregates in concrete”, which started in July 2015 [1]. This method was based on a literature survey on the subject, on a method first developed at Univ. Laval (Quebec City, Canada) and on other works developed at Institute Eduardo Torroja IETcc-CSIC (Spain), LNEC (Portugal) and LCPC (France). Five aggregates with different mineralogy and origin (phonolite, cataclasite, granodiorite, granite and a sea dredge basalt) were immersed in specific volumes of NaOH or KOH solutions with excess calcium hydroxide maintained at 38 °C and 60 ºC. At 2, 6, 13, 26 and 52 weeks, samples of the immersion test solution were removed by pipetting and chemically analysed for potassium (NaOH test solution) or sodium (KOH test solution). The amount of alkalis released were expressed in grams of Na2O, K2O, and Na2Oe per kilogram of aggregates. In this article, the results obtained of alkalis releasable by the tested aggregates are presented and, based in the obtained data, several changes are proposed in the test method in order to improve it. The main subjects of discussion were to avoid the agglomeration of fine aggregates and the alkali precipitation by reaction especially with fine aggregates, to promote the stabilization of the solution, to reduce the errors related to the method and mainly, to reduce the test time to 26 weeks instead of to 52. In addition, the test temperature is set at 38 °C due to no significant differences in the results obtained at 60 °C. The obtained results show that most of the aggregates tested release higher quantity of alkalis at 60 ºC than at 38 °C, except for cataclasite and granodiorite which present similar results at both temperatures. Also, it was observed a higher release of Na+ than K+, except for granodiorite and granite. Moreover, after 52 weeks of testing, the alkali release from aggregates has still not reached a plateau. The obtained results show a high dispersion between laboratories, which was attributed to the different amount of excess of calcium hydroxide used, the variation in the acidification of alkaline solutions before the chemical analysis, and the different analytical methods used by different laboratories as well as the calibrating method

    Current role of the chimney technique in the treatment of complex abdominal aortic pathologies: A position paper from the PERICLES Registry investigators

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    Historically, chimney/snorkel endovascular aortic repair (Ch-EVAR) emerged as a rescue technique to revascularize and/or preserve inadvertently covered critical branch vessels during infrarenal aortic endografting. Next, in its evolutionary path, Ch-EVAR offered a viable treatment option for complex aortic repair, and particularly in situations where fenestrated/ branched EVAR was not a therapeutic option due to the lack of availability and/or anatomical constraints. In this context, this technique offered distinct advantages such as off-the-shelf availability, straightforward implantation techniques, and lower resource use-intensity enabling performance by a large number of operators managing patients in many centers around the world
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