19,055 research outputs found

    Effect of stent position on flow characteristics in a cerebral aneurysm

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    The position of an intracranial stent in relation to the ostium of a cerebral aneurysm can significantly affect the blood flow characteristics through the ostium and inside the aneurysm. An idealised cerebral artery and aneurysm were simulated with a pulsatile flow. Simulation results show that the effect on mass inflow between two stent positions is about 20% whereas the difference in the porosity effect of the pattern at these two positions is around 3%. The remainder may be attributed to differences in flow velocity profile across the stent into the aneurysm. The implications for clinical practice are an important consideration as the surgeon may place the stent in any position between the two investigated and hence this will lead to markedly different stent performance. Therefore, computational tools that take into account the variability of stent placement will be valuable for assisting surgical planning

    Galaxy Alignments in Very X-ray Luminous Clusters at z>0.5

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    We present the results of a search for galaxy alignments in 12 galaxy clusters at z>0.5, a statistically complete subset of the very X-ray luminous clusters from the MAssive Cluster Survey (MACS). Using high-quality images taken with the Hubble Space Telescope (HST) that render measurement errors negligible, we find no radial galaxy alignments within 500 kpc of the cluster centres for a sample of 545 spectroscopically confirmed cluster members. A mild, but statistically insignificant trend favouring radial alignments is observed within a radius of 200 kpc and traced to galaxies on the cluster red sequence. Our results for massive clusters at z>0.5 are in stark contrast to the findings of previous studies which find highly significant radial alignments of galaxies in nearby clusters at z~0.1 out to at least half the virial radius using imaging data from the SDSS. The discrepancy becomes even more startling if radial alignment becomes more prevalent at decreasing clustercentric distance, as suggested by both our and previous work. We investigate and discuss potential causes for the disparity between our findings based on HST images of clusters at z>0.5 and those obtained using groundbased images of systems at z~0.1. We conclude that the most likely explanation is either dramatic evolution with redshift (in the sense that radial alignments are less pronounced in dynamically younger systems) or the presence of systematic biases in the analysis of SDSS imaging data that cause at least partly spurious alignment signals.Comment: 10 pages, 11 figures, and 1 table. Accepted for publication in MNRA

    Nature-based solutions for urban agriculture in buildings: challenges and opportunities

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    Insight is given to food security being an actual issue of concern due to rapid growth of global population, availability of arable land and consequently increase demand of food. Some problems associated with climate change such as extreme weather and soil degradation will also affect the quality and quantity of crops. On the other hand, urban area with high population relies on rural area to supply food ingredients. The linear food system creates environmental problems such as carbon footprint for transportation and increase packaging materials waste. Current Covid-19 pandemic situation adds on pressure on developed cities with mere local agriculture such as Macao. Macao depends on mainland China for fresh fruits and vegetables supply since local production is not the main trend. Due to the above reasons, this study intents to provide a new insight on food production in urban context towards a more sustainable and healthier environment using nature-based solutions. Assessment of indoor farming feasibility in city will be carried out by literature review and business entities interviews. A survey will be developed about the public acceptance to produce food in buildings with nature-based solutions. The methodology will proceed with a state-of-the-art assessment followed by a systematic review focused on selected NBS. Statical analysis will be carried out for data assessment.info:eu-repo/semantics/publishedVersio

    Isolation and characterization of Faecalibacterium prausnitzii from calves and piglets.

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    The goal of our study was to isolate and characterize Faecalibacterium prausnitzii from fecal samples of healthy calves and piglets, in order to develop a novel probiotic for livestock animals. We identified 203 isolates of Faecalibacterium sp., which were clustered in 40 genetically distinct groups. One representative isolate from each cluster was selected for further characterization. The concentrations of the short chain fatty acids (SCFA) acetate, butyrate, propionate and isobutyrate in the culture media were measured by gas chromatography. We observed reduction in the concentration of acetate followed by concomitant increase in the concentration of butyrate, suggesting that the isolates were consuming acetate present in the media and producing butyrate. Butyrate production correlated positively with bacterial growth. Since butyrate has many benefits to the colonic epithelial cells, the selection of strains that produce higher amounts of butyrate is extremely important for the development of this potential probiotic. The effect of pH and concentration of bile salts on bacterial growth was also evaluated in order to mimic the conditions encountered by F. prausnitzii in vivo. The optimal pH for growth ranged between 5.5 and 6.7, while most isolates were inhibited by of the lowest concentration of bile salts tested (0.1%). Antimicrobial resistance profile showed that most isolates of Faecalibacterium sp. were resistant against ciprofloxacin and sulfamethoxazole-trimethoprim. More than 50% of the isolates were resistant to tetracycline, amikacin, cefepime and cefoxitin. A total of 19 different combinations of multidrug resistance were observed among the isolates. Our results provide new insights into the cultural and physiological characteristics of Faecalibacterium prausnitzii illustrating large variability in short chain fatty acid production, in vitro growth, sensitivity to bile salts, and antibiotic resistance and suggesting that future probiotic candidates should be carefully studied before elected for in vivo studies

    Active nuclear import of the deacetylase Sirtuin-2 is controlled by its C-terminus and importins

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    The NAD-dependent deacetylase Sirtuin-2 (SIRT2) functions in diverse cellular processes including the cell cycle, metabolism, and has important roles in tumorigenesis and bacterial infection. SIRT2 predominantly resides in the cytoplasm but can also function in the nucleus. Consequently, SIRT2 localisation and its interacting partners may greatly impact its function and need to be defined more clearly. In this study we used mass spectrometry to determine the interactomes of SIRT2 in whole cells and in specific cellular fractions; cytoplasm, nucleus and chromatin. Using this approach, we identified novel interacting partners of SIRT2. These included a number of proteins that function in nuclear import. We show that multiple importins interact with and contribute to the basal nuclear shuttling of SIRT2 and that one of these, IPO7 is required for SIRT2 mediated H3K18 deacetylation in response to bacterial infection. Furthermore, we reveal that the unstructured C-terminus of SIRT2 negatively regulates importin-binding and nuclear transport. This study demonstrates that SIRT2 is actively transported into the nucleus via a process regulated by its C-terminus and provides a resource of SIRT2 interacting partners

    Morte súbita e angina vasoespástica

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    Variant angina is defined by chest pain occurring at rest associated with transitory ST segment elevation on ECG, and is caused by a spasm of a coronary artery. Frequently, variant angina is associated with atherosclerotic coronary obstruction and patients with normal coronary arteries are rare. Patients with variant angina and normal coronary arteries have good prognosis, and the development of ventricular arrhythmias or sudden death is rare. The authors present two cases of sudden cardiac death in patients with variant angina and normal coronary arteries

    Smells Like Anthelmintic Resistance-Gastrointestinal Prevalence, Burden and Diversity in Dogs from Portugal

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    Anthelmintic resistance has been documented worldwide, but few cases have been reported in dogs. Shelter dogs are a great opportunity to study intestinal helminths and assess their potential resistance to anthelmintic compounds. With these two goals in mind, 361 faecal samples were collected from dogs in 18 municipalities in Portugal, from 19 shelters and 11 private tutors. These samples were analysed using the Mini-FLOTAC before and 13 days after deworming. The percentage of faecal egg count reduction was calculated. Parasitic forms were identified in 22.4% of the samples collected: Trichuris vulpis (10.5%), Toxocara canis (8.0%), members of the family Ancylostomatidae (6.4%), Toxascaris leonina (0.8%), Dipylidium caninum (0.6%) and members of the family Taeniidae (0.3%). The first three nematode parasites showed the highest intensity of infection (2900, 1325, and 1265 eggs per gram, respectively). In the second faecal collection, parasites were present in 20.8% of the samples. The anthelmintics febendazole + pyrantel embonate + praziquantel and praziquantel + fenbendazole were ineffective for T. vulpis and members of the family Ancylostomatidae in 16.2% and 6.9% of the samples, respectively. The parasites identified are all potentially zoonotic. This study is the first to suggest a potential resistance of T. vulpis to anthelmintics.The participation of Teresa Letra Mateus was funded by national funds through FCT—Fundação para a Ciência e Tecnologia, I.P., with the scope of the project UIDB/05937/2020 with DOI identifier https://doi.org/10.54499/UIDB/05937/2020 and UIDP/05937/2020 with DOI identifier https://doi.org/10.54499/UIDP/05937/2020. The participation of Maria Aires Pereira was supported by the projects GHTM—UID/04413/2020 and LA-REAL-LA/P/0117/2020, and CERNAS UIDB/00681/2020, funded by the Portuguese Foundation for Science and Technology (FCT). The participation of Cláudio Araújo-Paredes was funded by national funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., within the scope of project UIDB/05975/2020

    Aeroallergens sensitization in an allergic paediatric population of Cova da Beira, Portugal.

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    Cova da Beira is an interior central region of Portugal, with a population of 93,000 inhabitants. The first pollen counts performed in Portugal revealed the highest values of the country in this area. The aim of this study was to assess the aeroallergens sensitization in an allergic population, according to the age groups. In a 5 year period (1995-2000) 1790 consecutive outpatients were observed for suspected allergic symptoms. We included in this study all the 557 paediatric (< or = 15 years old) observed patients (317 male (57%) and 240 female (43%) with an average age of 7.6 < or = 4.2 years old). They were divided in three age groups (Group I: < or = 5 yr; Group II: 6-10 yr; Group III: 11-15 yr). 371 patients were submitted to skin prick tests to aeroallergens. 86.5% of these patients were sensitised to at least one allergen extract. The most representative aeroallergens sensitization were grasses mixture (44.9%), D. pteronyssinus (32.5%), D. farinae (29.1%), Olea europea (27.5%), Parietaria judaica (23.4%), cat dander (16.1%), Artemisia vulgaris (17.6%), Robinia pseudoacacia (12.2%), Platanus acerifolia (11.4%), Tilia cordata (11.4%) moulds mixture (11.2%), Plantago lanceolata (10.6%), dog dander (10.4%), and Pinus radiata (7.5%). The sensitisation to indoor aeroallergens, was similar in all age groups and it was less important than that of pollens. The prevalence of sensitisation to grasses was the greatest in all ages and the house dust mites sensitization was the second most prevalent. The highest pollens counts in this region could explain the early sensitisation even in young children
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