193 research outputs found

    About the Dynamic Behaviour of Composite Bars Reinforced with Cotton or Hemp Fibers

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    In this paper, the authors designed several green composites with natural reinforcements (hemp and cotton fibers) and the matrix is a synthetic resin (epoxy resin). On having produced the samples, the authors determined the dynamic mechanical characteristics. The dynamic parameters were determined from the bar free vibrations. The next experimental rig was used: the bars were clamped at one end and left free at the other end. At the free end, a Bruel&Kjaer accelerometer with 0.04 pC/ms-2 sensitivity was placed, in order to record the beam dynamic response. A force was applied at the free end to bend the beams, and after bending, the force was cancelled and the beams were left to vibrate freely. The accelerometer was connected to a Nexus signal conditioner, and the signal conditioner was connected to a SPIDER 8 data acquisition system made by Hottinger Baldwin Messtec. The acquisition system was connected to a notebook and the experimental parameters were obtained through the CATMAN EASY software. From the free vibrations recording, the next mechanical parameters were determined: the eigenfrequency of the first eigenmode, the damping factors per mass unit and per unit length, the loss factor and the dynamic Young modulus and stiffness. From the results obtained, it can be concluded that the materials with epoxy resin reinforced with hemp have better vibration damping properties as compared to the composites made from epoxy reinforced with cotton fibers

    Meningioma of the pineal region

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    Meningiomas rarely occur in the pineal region, but they can reach huge diameters. We presented the case of a patient with a very large meningioma of the pineal region (6x5x4 cm). The tumor, developed from the falcotentorial junction, was totally removed via an occipital interhemispheric transtentorial approach with minimal postoperative neurological deficits. The postoperative course was complicated with an acute internal hydrocephalus that needed temporary placement of an external ventricular drainage. The supratentorial surgical corridors allow for increased exposure and are best suited for falcotentorial meningiomas

    Luminescence properties of mechanically milled and laser irradiated ZnO

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    The effect of mechanical milling on the luminescence properties of ZnO microcrystalline samples has been studied by means of cathodoluminescence in a scanning electron microscope. The samples consisted of pressed pellets of commercially available ZnO powder which were ball milled to investigate the possibility of nanocrystalline ZnO formation. Changes observed in the relative intensities of the characteristic ultraviolet and green band of ZnO are discussed in terms of defects generated during milling. The effect of nano- and picosecond pulsed laser irradiation on the particle size and luminescence of the milled samples has been also investigated

    Radiofrequency ablation in primary colo-rectal cancer and liver metastasis

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    Institutul Oncologic Bucuresti, Clinica de Chirurgie Nr. 1, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Ablaţia prin radiofrecvenţă constituie o soluţie terapeutică recentă în chirurgia determinărilor primare sau secundare din neoplasmele colorectale. Realizată prin abord deschis, laparo-endoscopic sau percutan, metoda asigură un control acceptabil asupra procesului tumoral, cu riscuri reduse comparativ cu chirurgia de exereză, cu condiţia respectării stricte a indicaţiilor. Obiective. Evaluăm această procedură terapeutică, aplicată pentru indicaţia clasică din metastazele hepatice, cât şi pentru tumorile rectale joase sau recidive pelvine după cancer rectal operat, prin prisma experienţei acumulate pe parcursul a 4 ani, focusând complicaţiile perioperatorii şi rata de recidivă locală şi evoluţia la distanţă. Metoda. În perioada decembrie 2006 – martie 2010 au fost trataţi prin radiofrecvenţă 64 pacienţi, 46 cu metastaze hepatice secundare CRC, iar 18 cu cancer rectal inferior sau recidive pelvine; procedura s-a realizat în majoritatea cazurilor sub control echografic intraoperator, prin abord chirurgical clasic în 59 cazuri, iar în 5 cazuri prin abord laparoscopic. Evoluţia pacienţilor a fost monitorizată imagistic prin CT postoperator la 30 zile, ulterior din 3 în 3 luni, urmărirea markerilor tumorali (CEA, CA19.9.) şi control endoscopic. Rezultate. Complicaţii perioperatorii s-au inregistrat la 6 pacienţi si au constat în sindroame febrile, citolize hepatice. Nu s-au înregistrat complicaţii de tipul hemoragiilor, fistulelor sau peritonitelor; şi nici mortalitate perioperatorie imputabilă metodei. Recidive locale înregistrate, la un interval de 6-25 luni, la 12 pacienți. Concluzii. Experienţa iniţială arată că radioablaţia în chirurgia determinărilor primare sau secundare din neoplasmele colo-rectale este o procedură relativ sigură, grefată de morbiditate redusă şi rata scazută de recidivă locală; urmează ca studii de urmărire pe perioade mai întinse să confirme valoarea metodei.Radiofrequency ablation represent a therapeutic option for primary colo-rectal cancer and liver metastasis, performed by open surgery, laparoscopic approach or percutaneous, provide a reasonable local tumor control, involved low risks comparative resection surgery. Objectives. We analyzed this procedure, for classic indication in hepatic metastatic tumors, as well as in low rectal tumors and pelvic recurrences after rectal surgery based on four years experience, focused on perioperative complications, recurrence rate and long distant evolution. Method. Between December 2006 and March 2010, 64 patients underwent RFA; 46 cases had metastatic lesions from colo-rectal cancer and 18 cases had low rectal cancer or pelvic recuurrence. RFA was performed in 59 patients via open surgery and laparoscopic approach in 5 patients. Postoperative course was followed with CT scan at 1 month, and then at 3 month interval, in correlation with tumor markers level (CEA, CA19.9.) and endoscopic control. Results. Perioperative complications occurred in 6 cases, consist of prolonged fever, severe hepatic cytolysis, without other complications such, biliary tract injury, hemorrhage, and peritonitis; no mortality caused by RFA procedure. 12 cases had local recurrence, at 6 and 25 month after post RFA procedure. Concluzii. Initial experience shows that RFA is a safe procedure for treatment of primary colo-rectal cancer and liver metastasis, with low rate of morbidity and local recurrence, indicated for patients with unresecable lesions or high risks for surgical resection

    Prevalence and Outcomes for Heavily Treatment-Experienced (HTE) Individuals Living with Human Immunodeficiency Virus in a European Cohort

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    BACKGROUND: Although antiretroviral treatments have improved survival of persons living with HIV, their long-term use may limit available drug options. We estimated the prevalence of heavily treatment-experienced (HTE) status and the potential clinical consequences of becoming HTE. SETTING: EuroSIDA, a European multicentre prospective cohort study. METHODS: A composite definition for HTE was developed, based on estimates of antiretroviral resistance and prior exposure to specific antiretroviral regimens. Risks of progressing to clinical outcomes were assessed by Poisson regression, comparing every HTE individual with three randomly-selected controls who never became HTE. RESULTS: Of 15,570 individuals under follow-up in 2010-2016, 1617 (10.4%, 95% CI 9.9-10.9%) were classified as HTE. 1093 individuals became HTE during prospective follow-up (HTE incidence rate 1.76, CI 1.66-1.87 per 100 person-years of follow-up). The number of HTE individuals was highest in West/Central Europe (636/4019 persons, 15.7%) and lowest in East Europe (26/2279 persons, 1.1%). Although most HTE individuals maintained controlled viral loads (<400 copies/ml), many had low CD4 counts (≤350 cells/µl). After controlling for age, immunological parameters and pre-existing comorbidities, HTE status was not associated with the risk of new AIDS (adjusted incidence rate ratio, aIRR 1.44, CI 0.86-2.40, p = 0.16) or non-AIDS clinical events (aIRR 0.96, CI 0.74-1.25, p = 0.77). CONCLUSIONS: HTE prevalence increased with time. After adjusting for key confounding factors, there was no evidence for an increased risk of new AIDS or non-AIDS clinical events in HTE. Additional therapeutic options and effective management of comorbidities remain important to reduce clinical complications in HTE individuals

    Refactoring GrPPI:Generic Refactoring for Generic Parallelism in C++

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    Funding: EU Horizon 2020 project, TeamPlay (https://www.teamplay-xh2020.eu), Grant Number 779882, UK EPSRC Discovery, grant number EP/P020631/1, and Madrid Regional Government, CABAHLA-CM (ConvergenciA Big dAta-Hpc: de Los sensores a las Aplicaciones) Grant Number S2018/TCS-4423.The Generic Reusable Parallel Pattern Interface (GrPPI) is a very useful abstraction over different parallel pattern libraries, allowing the programmer to write generic patterned parallel code that can easily be compiled to different backends such as FastFlow, OpenMP, Intel TBB and C++ threads. However, rewriting legacy code to use GrPPI still involves code transformations that can be highly non-trivial, especially for programmers who are not experts in parallelism. This paper describes software refactorings to semi-automatically introduce instances of GrPPI patterns into sequential C++ code, as well as safety checking static analysis mechanisms which verify that introducing patterns into the code does not introduce concurrency-related bugs such as race conditions. We demonstrate the refactorings and safety-checking mechanisms on four simple benchmark applications, showing that we are able to obtain, with little effort, GrPPI-based parallel versions that accomplish good speedups (comparable to those of manually-produced parallel versions) using different pattern backends.Publisher PDFPeer reviewe

    Disparities in HIV clinic care across Europe: findings from the EuroSIDA clinic survey

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    BACKGROUND: Although advances in HIV medicine have yielded increasingly better treatment outcomes in recent years, HIV-positive people with access to antiretroviral therapy (ART) still face complex health challenges. The EuroSIDA Study Group surveyed its clinics to explore regional differences in clinic services. METHODS: The EuroSIDA study is a prospective observational cohort study that began enrolling patients in 1994. In early 2014, we conducted a 59-item survey of the 98 then-active EuroSIDA clinics. The survey covered HIV clinical care and other aspects of patient care. The EuroSIDA East Europe study region (Belarus, Estonia, Lithuania, the Russian Federation and Ukraine) was compared to a “non-East Europe” study region comprised of all other EuroSIDA countries. RESULTS: A larger proportion of clinics in the East Europe group reported deferring ART in asymptomatic patients until the CD4 cell count dropped below 350 cells/mm3 (75 % versus 25 %, p = 0.0032). Considerably smaller proportions of East Europe clinics reported that resistance testing was provided before ART initiation (17 % versus 86 %, p < 0.0001) and that it was provided upon treatment failure (58 % versus 90 %, p = 0.0040). Only 33 % of East Europe clinics reported providing hepatitis B vaccination, compared to 88 % of other clinics (p < 0.0001). Only 50 % of East Europe clinics reported having access to direct-acting antivirals for hepatitis C treatment, compared to 89 % of other clinics (p = 0.0036). There was significantly less tuberculosis/HIV treatment integration in the East Europe group (27 % versus 84 % p < 0.0001) as well as significantly less screening for cardiovascular disease (58 % versus 90 %, p = 0.014); tobacco use (50 % versus 93 %, p < 0.0001); alcohol consumption (50 % versus 93 %, p < 0.0001); and drug use (58 % versus 87 %, p = 0.029). CONCLUSIONS: Study findings demonstrate how specific features of HIV clinics differ across Europe. Significantly more East Europe clinics deferred ART in asymptomatic patients for longer, and significantly fewer East Europe clinics provided resistance testing before initiating ART or upon ART failure. The East Europe group of clinics also differed in regard to hepatitis B vaccination, direct-acting antiviral access, tuberculosis/HIV treatment integration and screening for other health issues. There is a need for further research to guide setting-specific decision-making regarding the optimal array of services at HIV clinics in Europe and worldwide

    Alpha-Gal on the Protein Surface Hampers Transcytosis through the Caco-2 Monolayer

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    Transepithelial transport of proteins is an important step in the immune response to food allergens. Mammalian meat allergy is characterized by an IgE response against the carbohydrate moiety galactosyl-α-1,3-galactose (α-Gal) present on mammalian glycoproteins and glycolipids, which causes severe allergic reactions several hours after red meat consumption. The delayed reaction may be related to the processing of α-Gal carrying proteins in the gastrointestinal tract. The aim of this study was to investigate how protein glycosylation by α-Gal affects the susceptibility to gastric digestion and transport through the Caco-2 cell monolayer. We found that α-Gal glycosylation altered protein susceptibility to gastric digestion, where large protein fragments bearing the α-Gal epitope remained for up to 2 h of digestion. Furthermore, α-Gal glycosylation of the protein hampered transcytosis of the protein through the Caco-2 monolayer. α-Gal epitope on the intact protein could be detected in the endosomal fraction obtained by differential centrifugation of Caco-2 cell lysates. Furthermore, the level of galectin-3 in Caco-2 cells was not affected by the presence of α-Gal glycosylated BSA (bovine serum albumin) (BSA-α-Gal). Taken together, our data add new knowledge and shed light on the digestion and transport of α-Gal glycosylated proteins

    Exploring cognitive and biological correlates of sleep quality and their potential links with Alzheimer's disease (ALFASleep project): protocol for an observational study

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    The growing worldwide prevalence of Alzheimer's disease (AD) and the lack of effective treatments pose a dire medical challenge. Sleep disruption is also prevalent in the ageing population and is increasingly recognised as a risk factor and an early sign of AD. The ALFASleep project aims to characterise sleep with subjective and objective measurements in cognitively unimpaired middle/late middle-aged adults at increased risk of AD who are phenotyped with fluid and neuroimaging AD biomarkers. This will contribute to a better understanding of the pathophysiological mechanisms linking sleep with AD, thereby paving the way for the development of non-invasive biomarkers and preventive strategies targeting sleep.We will invite 200 participants enrolled in the ALFA+ (for ALzheimer and FAmilies) prospective observational study to join the ALFASleep study. ALFA+ participants are cognitively unimpaired middle-aged/late middle-aged adults who are followed up every 3 years with a comprehensive set of evaluations including neuropsychological tests, blood and cerebrospinal fluid (CSF) sampling, and MRI and positron emission tomography acquisition. ALFASleep participants will be additionally characterised with actigraphy and CSF-orexin-A measurements, and a subset (n=90) will undergo overnight polysomnography. We will test associations of sleep measurements and CSF-orexin-A with fluid biomarkers of AD and glial activation, neuroimaging outcomes and cognitive performance. In case we found any associations, we will test whether changes in AD and/or glial activation markers mediate the association between sleep and neuroimaging or cognitive outcomes and whether sleep mediates associations between CSF-orexin-A and AD biomarkers.The ALFASleep study protocol has been approved by the independent Ethics Committee Parc de Salut Mar, Barcelona (2018/8207/I). All participants have signed a written informed consent before their inclusion (approved by the same ethics committee). Study findings will be presented at national and international conferences and submitted for publication in peer-reviewed journals.NCT04932473.© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ

    Compensatory-reserve-weighted intracranial pressure versus intracranial pressure for outcome association in adult traumatic brain injury: a CENTER-TBI validation study

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    Background: Compensatory-reserve-weighted intracranial pressure (wICP) has recently been suggested as a supplementary measure of intracranial pressure (ICP) in adult traumatic brain injury (TBI), with a single-center study suggesting an association with mortality at 6 months. No multi-center studies exist to validate this relationship. The goal was to compare wICP to ICP for association with outcome in a multi-center TBI cohort. Methods: Using the Collaborative European Neuro Trauma Effectiveness Research in TBI (CENTER-TBI) high-resolution intensive care unit (ICU) cohort, we derived ICP and wICP (calculated as wICP = (1 12 RAP) 7 ICP; where RAP is the compensatory reserve index derived from the moving correlation between pulse amplitude of ICP and ICP). Various univariate logistic regression models were created comparing ICP and wICP to dichotomized outcome at 6 to 12 months, based on Glasgow Outcome Score\u2014Extended (GOSE) (alive/dead\u2014GOSE 65 2/GOSE = 1; favorable/unfavorable\u2014GOSE 5 to 8/GOSE 1 to 4, respectively). Models were compared using area under the receiver operating curves (AUC) and p values. Results: wICP displayed higher AUC compared to ICP on univariate regression for alive/dead outcome compared to mean ICP (AUC 0.712, 95% CI 0.615\u20130.810, p = 0.0002, and AUC 0.642, 95% CI 0.538\u2013746, p &lt; 0.0001, respectively; no significant difference on Delong\u2019s test), and for favorable/unfavorable outcome (AUC 0.627, 95% CI 0.548\u20130.705, p = 0.015, and AUC 0.495, 95% CI 0.413\u20130.577, p = 0.059; significantly different using Delong\u2019s test p = 0.002), with lower wICP values associated with improved outcomes (p &lt; 0.05 for both). These relationships on univariate analysis held true even when comparing the wICP models with those containing both ICP and RAP integrated area under the curve over time (p &lt; 0.05 for all via Delong\u2019s test). Conclusions: Compensatory-reserve-weighted ICP displays superior outcome association for both alive/dead and favorable/unfavorable dichotomized outcomes in adult TBI, through univariate analysis. Lower wICP is associated with better global outcomes. The results of this study provide multi-center validation of those seen in a previous single-center study
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