151 research outputs found
Micro-computed tomography (μ-CT) as a potential tool to assess the effect of dynamic coating routes on the formation of biomimetic apatite layers on 3D-plotted biodegradable polymeric scaffolds
This work studies the influence of dynamic
biomimetic coating procedures on the growth of bonelike
apatite layers at the surface of starch/polycaprolactone
(SPCL) scaffolds produced by a 3D-plotting technology.
These systems are newly proposed for bone Tissue Engineering
applications. After generating stable apatite layers
through a sodium silicate-based biomimetic methodology the
scaffolds were immersed in Simulated Body Fluid solutions
(SBF) under static, agitation and circulating flow perfusion
conditions, for different time periods. Besides the typical
characterization techniques, Micro-Computed Tomography
analysis (μ-CT) was used to assess scaffold porosity and as a
new tool for mapping apatite content. 2D histomorphometric
analysis was performed and 3D virtual models were created
using specific softwares for CT reconstruction. By the proposed
biomimetic routes apatite layers were produced covering
the interior of the scaffolds, without compromising their
overall morphology and interconnectivity. Dynamic conditions
allowed for the production of thicker apatite layers as
consequence of higher mineralizing rates, when comparing
with static conditions. μ-CT analysis clearly demonstrated
that flow perfusion was the most effective condition in order
to obtain well-defined apatite layers in the inner parts
of the scaffolds. Together with SEM, this technique was a useful complementary tool for assessing the apatite content
in a non-destructive way
Effects of demand-side financing on utilisation, experiences and outcomes of maternity care in low- and middle-income countries: a systematic review.
Demand-side financing, where funds for specific services are channelled through, or to, prospective users, is now employed in health and education sectors in many low- and middle-income countries. This systematic review aimed to critically examine the evidence on application of this approach to promote maternal health in these settings. Five modes were considered: unconditional cash transfers, conditional cash transfers, short-term payments to offset costs of accessing maternity services, vouchers for maternity services, and vouchers for merit goods. We sought to assess the effects of these interventions on utilisation of maternity services and on maternal health outcomes and infant health, the situation of underprivileged women and the healthcare system
Zebrafish Ciliopathy Screen Plus Human Mutational Analysis Identifies C21orf59 and CCDC65 Defects as Causing Primary Ciliary Dyskinesia
Primary ciliary dyskinesia (PCD) is caused when defects of motile cilia lead to chronic airway infections, male infertility, and situs abnormalities. Multiple causative PCD mutations account for only 65% of cases, suggesting that many genes essential for cilia function remain to be discovered. By using zebrafish morpholino knockdown of PCD candidate genes as an in vivo screening platform, we identified c21orf59, ccdc65, and c15orf26 as critical for cilia motility. c21orf59 and c15orf26 knockdown in zebrafish and planaria blocked outer dynein arm assembly, and ccdc65 knockdown altered cilia beat pattern. Biochemical analysis in Chlamydomonas revealed that the C21orf59 ortholog FBB18 is a flagellar matrix protein that accumulates specifically when cilia motility is impaired. The Chlamydomonas ida6 mutant identifies CCDC65/FAP250 as an essential component of the nexin-dynein regulatory complex. Analysis of 295 individuals with PCD identified recessive truncating mutations of C21orf59 in four families and CCDC65 in two families. Similar to findings in zebrafish and planaria, mutations in C21orf59 caused loss of both outer and inner dynein arm components. Our results characterize two genes associated with PCD-causing mutations and elucidate two distinct mechanisms critical for motile cilia function: dynein arm assembly for C21orf59 and assembly of the nexin-dynein regulatory complex for CCDC65
An Outer Arm Dynein Conformational Switch Is Required for Metachronal Synchrony of Motile Cilia in Planaria
Here we use the motile ventral cilia of the planarian S. mediterranea to examine the role of outer arm dynein in the generation and maintenance of metachronal synchrony. We demonstrate that a single dynein light chain plays a mechanosensory role necessary to entrain and maintain the metachronal synchrony of motile cilia
Improving EFL Education in Morocco: Strategies for Success
This article explores the current state of English as a Foreign Language (EFL) education in Morocco, identifies key challenges, and proposes strategies for improvement. Through a mixed-methods approach involving surveys and interviews with EFL teachers and students, the study highlights issues such as inadequate teacher training, out-dated curricula, and limited access to resources. The findings suggest that professional development for teachers, curriculum reform, integration of technology, and student-centred teaching approaches are crucial for enhancing EFL education in Morocco. The article concludes with practical recommendations and a call for policy support
The Impact of Code Switching on Moroccan EFL Teachers' Language Proficiency
This study explores the impact of code-switching on the language proficiency of Moroccan EFL teachers. A mixed-methods approach is used, combining surveys, interviews, and classroom observations to explore how code-switching affects teachers' language skills. The findings reveal that code-switching is a prevalent practice, primarily used to facilitate comprehension and classroom management in multilingual settings. While teachers view it as an effective strategy for bridging linguistic gaps, there are concerns about its long-term implications. Survey results show a high frequency of code-switching, suggesting its effectiveness in addressing linguistic diversity. However, interviews highlight a divide in perceptions, with some teachers fearing that frequent code-switching may limit their exposure to English and reduce opportunities for spontaneous language practice. Classroom observations support the strategic use of code-switching to enhance teaching effectiveness, though excessive use may hinder both teachers' and students' language development by limiting immersion in English. The study underscores the need for a balanced approach to code-switching, ensuring it serves pedagogical goals without compromising language proficiency
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