28 research outputs found

    Incidence of acute cerebrovascular events in patients with rheumatic or calcific mitral stenosis: a systematic review and meta-analysis

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    Background Patients with mitral stenosis (MS) may be predisposed to acute cerebrovascular events (ACE) and peripheral thromboembolic events (TEE). Concomitant atrial fibrillation (AF), mitral annular calcification (MAC) and rheumatic heart disease (RHD) are independent risk factors. Our aim was to evaluate the incidence of ACEs in MS patients and the implications of AF, MAC, and RHD on thromboembolic risks. Methods This systematic review was registered on PROSPERO (CRD42021291316). Six databases were searched from inception to 19th December 2021. The clinical outcomes were composite ACE, ischaemic stroke/transient ischaemic attack (TIA), and peripheral TEE. Results We included 16 and 9 papers, respectively, in our qualitative and quantitative analyses. The MS cohort with AF had the highest incidence of composite ACE (31.55%; 95%CI 3.60-85.03; I 2 =99%), followed by the MAC (14.85%; 95%CI 7.21-28.11; I 2 =98%), overall MS (8.30%; 95%CI 3.45-18.63; I 2 =96%) and rheumatic MS population (4.92%; 95%CI 3.53-6.83; I 2 =38%). Stroke/TIA were reported in 29.62% of the concomitant AF subgroup (95%CI 2.91-85.51; I 2 =99%) and in 7.11% of the overall MS patients (95%CI 1.91-23.16; I 2 =97%). However, the heterogeneity of the pooled incidence of clinical outcomes in all groups, except the rheumatic MS group, were substantial and significant. The logit-transformed proportion of composite ACE increased by 0.0141 (95% CI 0.0111-0.0171; p<0.01) per year of follow-up. Conclusion In the MS population, MAC and concomitant AF are risk factors for the development of ACE. The scarcity of data in our systematic review reflects the need for further studies to explore thromboembolic risks in all MS subtypes

    Cytotoxic activity induced by crude extracts of Ganoderma lucidum (W. Curt.: Fr.) P. Karst. on mouse myeloma cancer cell-line

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    Ganoderma lucidum powder using hot water and methanol extraction methods indicated a twofold more active cytotoxic activity with IC50 of 44 ± 3.8 μg/ml in the latter method. The representative dose-response curves of the G. lucidum crude extracts on J558 cell-lines revealed that there were great similarities between the curves which reflected rapid killing activities. The percentage viability of the J558 cell exposed to these crude extracts was dose dependent only up to 150 μg/ml. After which, there was no significant reduction when the dose was increased to 200 or 400 μg/ml. The morphological alterations induced by the crude extract were examined under the phase contrast, fluorescent and electron microscopy. When J558 cells were treated with doses higher than 50 μg/ml of the crude extract, obvious morphological changes and apoptosis occurred after 72 h. At 400 μg/ml, most of the cells showed necrosis characterized as small fragments with uniformly stained red nuclei. The apoptotic and necrotic cells increased by 16.5 and 29.1%, respectively whereas the viable cells decreased by as much as 45.6. The mode of cell death via apoptosis was 3.6% higher than necrosis. However, these morphological changes were not observed in the case of 3T3 cells. Results obtained from scanning electron microscopy and transmission electron microscopy further confirmed the occurrence of various apoptotic and necrotic features

    Information and Communication Technology in Mathematics Education – Integration Readiness in Tanzania Higher Education Institutions

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    Part 4: Sustainable ICT, Informatics, Education and Learning in a Turbulent World - “Doing the Safari Way”International audienceThe use of ICT tools in mathematics instructions has been proved to have a positive impact on students’ success. However, little is known about the ICT readiness of both teachers and students to incorporate these tools in mathematics teaching-learning process. This study investigates the readiness of teachers and students to integrate ICT in mathematics teaching and learning at a higher education institution in Tanzania. Specifically the study assesses the device, skills and psychological readiness of teachers and students to integrate ICT tools in mathematics instructions. The study employs both qualitative and quantitative methods whereby data are collected through interviews and questionnaires respectively. Seven teachers and 129 bachelor degree students pursuing business studies, form the study population. Descriptive statistics are used to analyze the quantitative data while qualitative data are analyzed through content analysis. Results show that teachers and students have device, skills and psychological readiness to integrate ICT in teaching and learning of mathematics. This is significant as it provides information that will be useful in planning the use of ICT tools to benefit teaching and learning. This study contributes to transfer and diffusion of technology discourses

    Incidence of acute cerebrovascular events in patients with rheumatic or calcific mitral stenosis: A systematic review and meta-analysis

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    Background: Patients with mitral stenosis (MS) may be predisposed to acute cerebrovascular events (ACE) and peripheral thromboembolic events (TEE). Concomitant atrial fibrillation (AF), mitral annular calcification (MAC) and rheumatic heart disease (RHD) are independent risk factors. Our aim was to evaluate the incidence of ACEs in MS patients and the implications of AF, MAC and RHD on thromboembolic risks. Methods: This systematic review was registered on PROSPERO (CRD42021291316). Six databases were searched from inception to 19th December 2021. The clinical outcomes were composite ACE, ischaemic stroke/transient ischaemic attack (TIA) and peripheral TEE. Results: We included 16 and 9 papers, respectively, in our qualitative and quantitative analyses. The MS cohort with AF had the highest incidence of composite ACE (31.55%; 95% CI 3.60–85.03; I2 = 99%), followed by the MAC (14.85%; 95% CI 7.21–28.11; I2 = 98%), overall MS (8.30%; 95% CI 3.45–18.63; I2 = 96%) and rheumatic MS population (4.92%; 95% CI 3.53–6.83; I2 = 38%). Stroke/TIA were reported in 29.62% of the concomitant AF subgroup (95% CI 2.91–85.51; I2 = 99%) and in 7.11% of the overall MS patients (95% CI 1.91–23.16; I2 = 97%). However, the heterogeneity of the pooled incidence of clinical outcomes in all groups, except the rheumatic MS group, was substantial and significant. The logit-transformed proportion of composite ACE increased by 0.0141 (95% CI 0.0111–0.0171; p < 0.01) per year of follow-up. Conclusion: In the MS population, MAC and concomitant AF are risk factors for the development of ACE. The scarcity of data in our systematic review reflects the need for further studies to explore thromboembolic risks in all MS subtypes

    Transport of hydrogen isotopes through interlayer spacing in van der Waals crystals

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    Atoms start behaving as waves rather than classical particles if confined in spaces commensurate with their de Broglie wavelength. At room temperature this length is only about one angstrom even for the lightest atom, hydrogen. This restricts quantum-confinement phenomena for atomic species to the realm of very low temperatures. Here we show that van der Waals gaps between atomic planes of layered crystals provide angstrom-size channels that make quantum confinement of protons apparent even at room temperature. Our transport measurements show that thermal protons experience a notably higher barrier than deuterons when entering van der Waals gaps in hexagonal boron nitride and molybdenum disulfide. This is attributed to the difference in de Broglie wavelength of the isotopes. Once inside the crystals, transport of both isotopes can be described by classical diffusion, albeit with unexpectedly fast rates, comparable to that of protons in water. The demonstrated angstrom-size channels can be exploited for further studies of atomistic quantum confinement and, if the technology can be scaled up, for sieving hydrogen isotopes
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