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- Newborn screening for sickle cell disease in Angola: implementation challenges and emerging data on hemoglobinopathy prevalencePublication . Brito, Miguel; Ginete, Catarina; Jacinto, Mariana; Mendes, Manuela; Soares, Hailton; Afonso, Roberto; Siatembo, Adriano; Vasconcelos, Jocelyne; Inusa, BabaSickle Cell Disease (SCD) is an autosomal recessive disorder with a substantial global burden. Despite its particularly high incidence in sub-Saharan Africa, early diagnosis remains limited in many countries. The objective of this study was to implement a newborn screening programme for SCD in one of the largest maternity hospitals in Angola and to support the subsequent pediatric follow-up of the affected children. Between June 2023 and December 2024, all children born in or attending the main hospital for vaccination were screened after parental or guardian consent. Blood was collected by heel-prick onto filter paper, and haemoglobin electrophoresis was performed by isoelectric focusing. Samples identified as HbSS were confirmed by PCR-RFLP, and atypical electrophoretic patterns were further analysed by DNA sequencing. In a total of 13,256 samples analysed, the prevalence of HbSS was 1.38% (n = 183), and 20.31% (n = 2692) were HbAS. Other variants identified (n = 44) included HbE, HbC, and α-globin gene alterations. Of the infants diagnosed with SCD, 106 (58%) families were successfully contacted, but only 76 (42%) children initiated regular medical follow-up and prophylactic treatment (penicillin, multivitamins, and vaccinations. 30 families (28%) declined treatment, and just one declined follow-up. These findings confirm the high prevalence of SCD in Angola and demonstrate the capacity of newborn screening programmes in reducing early morbidity and mortality. However, the substantial proportion of families refusing follow-up highlights the need for strengthened community health education to improve understanding of SCD.
- Finite element analysis of non-uniform functionally graded multi-cracked Timoshenko beams using an equilibrium-based formulationPublication . Freixial Argente dos Santos, Hugo Alexandre; Silberschmidt, V. V.A novel finite element formulation is introduced for the static analysis of non-uniform functionally graded multi-cracked Timoshenko beams with small deformations. The cracks, assumed to remain open, are modelled using the so-called discrete spring approach, in which Dirac delta generalized functions are introduced into the bending flexibility of the beams. The formulation is derived on the basis of a complementary variational approach that involves only the elements' shear forces and bending moments as the fundamental unknown fields. The corresponding element flexibility matrix is obtained in closed-form, with the crack contributions explicitly separated from the standard bending and shear flexibility terms. The numerical solutions produced by the formulation are strictly equilibrated, i.e., they satisfy all equilibrium conditions of the associated boundary-value problem in strong form. The effectiveness and accuracy of the formulation are numerically assessed through its application to several benchmark problems. The obtained results are analysed and compared, where possible, to exact (or reference) solutions and solutions given by the standard displacement-based finite element formulation, clearly illustrating the capability of the formulation to deliver highly accurate results for both thin and thick beams, even on meshes with only a few degrees-of-freedom.