Thermodynamic Modeling Study of Carbonation of Portland Cement

The assessment of the extent of carbonation and related phase changes is important for the evaluation of the durability aspects of concrete. The phase assemblage of Portland cements with different clinker compositions is evaluated using thermodynamic calculations. Four different compositions of cements, as specified by ASTM cements types I to IV, are considered in this study. Calcite, zeolites, and gypsum were identified as carbonation products. CO₂ content required for full carbonation had a direct relationship with the initial volume of phases. The CO₂ required for portlandite determined the initiation of carbonation of C-S-H. A continual decrease in the pH of pore solution and a decrease in Ca/Si is observed with the carbonation of C-S-H. Type II cement exhibited rapid carbonation at relatively less CO₂for full carbonation, while type III required more CO₂ to carbonate to the same level as other types of cement. The modeling of carbonation of different Portland cements provided insights into the quantity of CO₂ required to destabilize different hydrated products into respective carbonated phases.     

Knowledge of the Therapeutic Goals of Diabetes Care among Patients with Type 2 Diabetes at a Tertiary Hospital in Ethiopia

BackgroundA comprehensive cardiovascular risk control reduces diabetes-associated complications but achieving the triplet goals (blood glucose, blood pressure (BP), and low-density lipoprotein (LDL-C)) remains a clinical challenge. Patients'' knowledge of these diabetes therapeutic goals has been shown to improve glycemic control. However, this is not well studied in Ethiopia.MethodsA cross-sectional study was conducted from March to June 2020 in Tikur Anbessa Specialized Hospital among randomly selected 419 patients with type 2 diabetes. Data was collected using a pretested, structured questionnaire. A multivariable binary logistic regression was fitted to identify determinants of knowledge.ResultsThe mean age (±SD) of study participants was 57.4 (±10.8) years and the median duration (IQR) of diabetes was 12 (7, 20) years. A quarter of them achieved fasting glycemic control, a fifth of them attained the A1c goal and only 3% achieved the triple targets. Patients who reported knowing their target goals for BP, fasting blood sugar (FBS), A1C, and LDL-C were 79.5, 77.3, 11.7, and 7.2% respectively. The factors associated with knowledge of the therapeutic goals were longer diabetes duration, increased household income, age, being divorced as compared to married, having no formal education, and primary education.ConclusionThe majority of participants knew their BP and FBS targets while only a minority understood their A1c and LDL-C targets. It highlighted the need for the provision of patient-centered diabetes education to improve knowledge of the therapeutic targets.     

Intravascular ultrasound assessment of the effect of laser energy on the arterial wall during the treatment of femoro-popliteal lesions: a CliRpath excimer laser system to enlarge lumen openings (CELLO) registry study

The CliRpath Excimer Laser System to Enlarge Lumen Openings (CELLO) registry included patients treated with modified excimer laser catheters for the endovascular treatment of peripheral artery disease affecting the superficial femoral artery (SFA) and proximal popliteal artery. The aim of this study was to assess, via intravascular ultrasound (IVUS) the dissections in the vessel wall following treatment with the laser catheters. IVUS grayscale images from the CELLO registry were systematically reviewed for dissections in the treated vessel segments by two investigators. Images from 33 patients; 66 pullbacks (1867 IVUS frames in 2 phases), were successfully matched frame-to-frame to evaluate identical segments of the treated vessels in the two phases; post-2 mm Turbo-Elite laser pilot channel creation and post Turbo-Booster laser atherectomy. Dissections were categorized as; (1) intimal, (2) medial, (3) intramural hematoma, and (4) adventitial according to the ACC Clinical Expert Consensus Document classification of dissections. An average of 57 frames was evaluated per pullback, giving a total of 3734 frames (1867 matched for pre-ablation (post channel creation) and post-ablation phases). Treatments with the modified Excimer laser catheters resulted in a significant increase in lumen area of 5.5?±?3.2-mm² (95% CI 4.3–6.8, p?<?0.0001) and reduction in plaque plus media volume of ?10.6?±?36.0 mm³ (95% CI ?25.8 to 4.6, p?=?0.1619) whilst giving rise to mainly intramural hematoma formations post Turbo-Booster laser treatment in 55% of frames assessed and 24% medial dissections with less than 1% adventitial disruption. The Excimer laser based Turbo-Booster treatment of peripheral artery lesions resulted in significant plaque debulking and increased lumen diameter with negligible degree of adventitial layer injury.     

Skilled delivery care service utilization in Ethiopia: analysis of rural-urban differentials based on national demographic and health survey (DHS) data

Background

Despite the slight progress made on Antenatal Care (ANC) utilization, skilled delivery care service utilization in Ethiopia is still far-below any acceptable standards. Only 10% of women receive assistance from skilled birth attendants either at home or at health institutions, and as a result the country is recording a high maternal mortality ratio (MMR) of 676 per 100,000 live births (EDHS, 2011). Hence, this study aimed at identifying the rural-urban differentials in the predictors of skilled delivery care service utilization in Ethiopia.

Methods

The study used the recent Ethiopian Demographic and Health Survey (EDHS 2011) data. Women who had at least one birth in the five years preceding the survey were included in this study. The data were analyzed using univariate (percentage), bivariate (chi-square) and multivariate (Bayesian logistic regression).

Results

The results showed that of the total 6,641 women, only 15.6% received skilled delivery care services either at home or at health institution. Rural women were at greater disadvantage to receive the service. Only 4.5% women in rural areas received assistance from skilled birth attendants (SBAs) compared to 64.1 % of their urban counter parts. Through Bayesian logistic regression analysis, place of residence, ANC utilization, women''s education, age and birth order were identified as key predictors of service utilization.

Conclusion

The findings highlight the need for coordinated effort from government and stakeholders to improve women''s education, as well as strengthen community participation. Furthermore, the study recommended the need to scale up the quality of ANC and family planning services backed by improved and equitable access, availability and quality of skilled delivery care services.     

Malaria in the Nuba Mountains of Sudan: baseline genotypic resistance and efficacy of the artesunate plus sulfadoxine-pyrimethamine and artesunate plus amodiaquine combinations

Both northern and southern Sudan are deploying artemisinin-based combinations against uncomplicated Plasmodium falciparum malaria (artesunate+sulfadoxine-pyrimethamine [AS+SP] in the north, artesunate+amodiaquine [AS+AQ] in the south). In 2003, we tested the efficacy of 3 day AS+SP and AS+AQ regimens in vivo in the isolated, seasonally endemic Nuba Mountains region (the first study of AS combinations in southern Sudan). We also analysed pre-treatment blood samples for mutations at the P. falciparum chloroquine transporter (Pfcrt) gene (associated with CQ resistance), and at the dihydrofolate reductase (Dhfr) gene (associated with pyrimethamine resistance). Among 161 randomized children under 5 years, PCR-corrected cure rates after 28 days were 91.2% (52/57, 95% CI 80.7-97.1) for AS+SP and 92.7% (51/55, 95% CI 82.4-98.0) for AS+AQ, with equally rapid parasite and fever clearance. The Pfcrt K76T mutation occurred in 90.0% (144/160) of infections, suggesting CQ would work poorly in this region. Overall, 82.5% (132/160) carried mutations at Dhfr (N51I, C59R or S108N, but not I164L), but triple mutants (more predictive of in vivo SP failure) were rare (3.1%). CQ use should be rapidly discontinued in this region. SP resistance may propagate rapidly, and AS+AQ is likely to be a better long-term option, provided AQ use is limited to the combination.     

Perception of dental fluorosis among adolescents living in urban areas of Ethiopia

The objective of the study was to assess the perception of dental fluorosis among adolescents residing in two urban areas in Ethiopia: Addis Ababa (low-fluoride drinking water) and Nazreth (high-fluoride drinking water). Students aged 12-15 years, enrolled in two junior secondary schools in Addis Ababa (n = 161) and two similar schools in Nazreth (n = 177) responded to evaluative statements concerning the appearance of anterior maxillary teeth. Color photographs depicting dental fluorosis (TF score 2, 3, 5 and 7) in maxillary front teeth were used as reference during structured interviews. A majority of the students from Addis Ababa and Nazreth were dissatisfied with the appearance of teeth having TF scores 2 and above. More than 66% of the students from both areas confirmed a need for dental consultation concerning fluorotic teeth with TF > or = [corrected] 2. As compared to their counterparts in Nazreth, children in Addis Ababa felt more embarrassed with TF score 2 and 3 (p < 0.01). TF scores 5 and 7 were found unacceptable both in Addis Ababa and in Nazreth. Students in Addis Ababa, more frequently than their counterparts in Nazreth, believed (erroneously) that dental fluorosis were related to neglect on the part of the child. The present findings confirm that fluorotic teeth constitute a social problem among junior secondary school children residing in low-fluoride as well as in high-fluoride urban areas in Ethiopia and, thereby, corroborate the public concern for safe drinking water.