356 research outputs found
Manipulating the morphology of poly (ethylene terephthlate) blends by capillary rheometry
The present work describes the formation of co-continuous phase morphologies in uncompatibilized and compatibilized poly(ethylene terephthalate) (PET)/poly(m-xylene adipamide) (MXD6) melt-extruded blends. Phase continuity has been determined by using Jordhamo relationship. Viscosity values which are essential for calculation of the phase continuity have been obtained by using capillary rheometry. Phase continuity has been investigated for the non-compatibilized and the compatibilized blends with scanning electron microscopy (SEM). PET/MXD6 blends (92.35/7.65 v/v and 84.5/15.5 v/v) exhibit a droplet-in-matrix phase morphology, while uncompatibilized PET/MXD6 (75.8/24.2 v/v) blend has a combination of rod-like, droplet/matrix structure, and quasi-interpenetrating network structure
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Modeling Air-flow in the Tracheobronchial Tree using Computational Fluid Dynamics
In this paper, we present a biomechanical framework to model air-flow inside the bronchus and deformations across the tracheobronchial tree, pipeline for the simulator, theory and initial steps to realize this framework on a highly parallel graphical processing unit (GPU). We discuss the main challenges expected and encountered to date. By using computational fluid dynamics (CFD) and computational solid dynamics (CSD) principles, we propose a numerical simulation framework that includes a biomechanical model of the tracheobronchial tree to simulate air flow inside the tree, on GPU in real-time. The proposed 3D biomechanical model to simulate the air inside the lungs coupled with a deformation model of the tracheobronchial tree, expressed through fluid-structure interaction, can be used to predict the transformations of the voxels from a 4D computed tomography (4DCT) dataset. Additionally, the proposed multi-functional CFD and CSD based framework is suitable for clinical applications such as adaptive lung radiotherapy, and a regional alveolar ventilation estimation
DNMT (DNA methyltransferase) inhibitors radiosensitize human cancer cells by suppressing DNA repair activity
<p>Abstract</p> <p>Background</p> <p>Histone modifications and DNA methylation are two major factors in epigenetic phenomenon. Unlike the histone deacetylase inhibitors, which are known to exert radiosensitizing effects, there have only been a few studies thus far concerning the role of DNA methyltransferase (DNMT) inhibitors as radiosensitizers. The principal objective of this study was to evaluate the effects of DNMT inhibitors on the radiosensitivity of human cancer cell lines, and to elucidate the mechanisms relevant to that process.</p> <p>Methods</p> <p>A549 (lung cancer) and U373MG (glioblastoma) cells were exposed to radiation with or without six DNMT inhibitors (5-azacytidine, 5-aza-2'-deoxycytidine, zebularine, hydralazine, epigallocatechin gallate, and psammaplin A) for 18 hours prior to radiation, after which cell survival was evaluated via clonogenic assays. Cell cycle and apoptosis were analyzed via flow cytometry. Expressions of DNMT1, 3A/3B, and cleaved caspase-3 were detected via Western blotting. Expression of ÎłH2AX, a marker of radiation-induced DNA double-strand break, was examined by immunocytochemistry.</p> <p>Results</p> <p>Pretreatment with psammaplin A, 5-aza-2'-deoxycytidine, and zebularine radiosensitized both A549 and U373MG cells. Pretreatment with psammaplin A increased the sub-G1 fraction of A549 cells, as compared to cells exposed to radiation alone. Prolongation of ÎłH2AX expression was observed in the cells treated with DNMT inhibitors prior to radiation as compared with those treated by radiation alone.</p> <p>Conclusions</p> <p>Psammaplin A, 5-aza-2'-deoxycytidine, and zebularine induce radiosensitivity in both A549 and U373MG cell lines, and suggest that this effect might be associated with the inhibition of DNA repair.</p
The vaginal microbiota associates with the regression of untreated cervical intraepithelial neoplasia 2 lesions
Emerging evidence suggests associations between the vaginal microbiota (VMB) composition, human papillomavirus (HPV) infection, and cervical intraepithelial neoplasia (CIN); however, causal inference remains uncertain. Here, we use bacterial DNA sequencing from serially collected vaginal samples from a cohort of 87 adolescent and young women aged 16â26 years with histologically confirmed, untreated CIN2 lesions to determine whether VMB composition affects rates of regression over 24 months. We show that women with a Lactobacillus-dominant microbiome at baseline are more likely to have regressive disease at 12 months. Lactobacillus spp. depletion and presence of specific anaerobic taxa including Megasphaera, Prevotella timonensis and Gardnerella vaginalis are associated with CIN2 persistence and slower regression. These findings suggest that VMB composition may be a future useful biomarker in predicting disease outcome and tailoring surveillance, whilst it may offer rational targets for the development of new prevention and treatment strategies
Gamification elements on social live streaming service mobile applications
Social live streaming services (SLSSs), a kind of synchronous social
networking service, are slowly but surely becoming a part of peopleâs daily lives. To keep users interested, a wide range of gamification elements are implemented on these services, increasing the user engagement and changing their behavior. This study examined 20 different SLSS mobile applications and the applied gamification elements. A literature review as well as a content analysis were used to find appropriate SLSS apps and game elements. What kind of mechanics can be found on SLSS mobile apps and how many are implemented on each system? On three of the observed apps we could identify all game elements. Chinese SLSS apps are the most gamified ones. On Ustream, no game element is implemented. The game mechanics following others as well as customization are the most often
applied; capturing a moment of a stream is the least often implemented
COVID-19 infection in adult patients with hematological malignancies: a European Hematology Association Survey (EPICOVIDEHA)
Background: Patients with hematological malignancies (HM) are at high risk of mortality from SARS-CoV-2 disease 2019 (COVID-19). A better understanding of risk factors for adverse outcomes may improve clinical management in these patients. We therefore studied baseline characteristics of HM patients developing COVID-19 and analyzed predictors of mortality. Methods: The survey was supported by the Scientific Working Group Infection in Hematology of the European Hematology Association (EHA). Eligible for the analysis were adult patients with HM and laboratory-confirmed COVID-19 observed between March and December 2020. Results: The study sample includes 3801 cases, represented by lymphoproliferative (mainly non-Hodgkin lymphoma n = 1084, myeloma n = 684 and chronic lymphoid leukemia n = 474) and myeloproliferative malignancies (mainly acute myeloid leukemia n = 497 and myelodysplastic syndromes n = 279). Severe/critical COVID-19 was observed in 63.8% of patients (n = 2425). Overall, 2778 (73.1%) of the patients were hospitalized, 689 (18.1%) of whom were admitted to intensive care units (ICUs). Overall, 1185 patients (31.2%) died. The primary cause of death was COVID-19 in 688 patients (58.1%), HM in 173 patients (14.6%), and a combination of both COVID-19 and progressing HM in 155 patients (13.1%). Highest mortality was observed in acute myeloid leukemia (199/497, 40%) and myelodysplastic syndromes (118/279, 42.3%). The mortality rate significantly decreased between the first COVID-19 wave (MarchâMay 2020) and the second wave (OctoberâDecember 2020) (581/1427, 40.7% vs. 439/1773, 24.8%, p value < 0.0001). In the multivariable analysis, age, active malignancy, chronic cardiac disease, liver disease, renal impairment, smoking history, and ICU stay correlated with mortality. Acute myeloid leukemia was a higher mortality risk than lymphoproliferative diseases. Conclusions: This survey confirms that COVID-19 patients with HM are at high risk of lethal complications. However, improved COVID-19 prevention has reduced mortality despite an increase in the number of reported cases.EPICOVIDEHA has received funds from Optics COMMITTM (COVID-19 Unmet Medical Needs and Associated Research Extension) COVID-19 RFP program by GILEAD Science, United States (Project 2020-8223)
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