The association between periodontal disease and adverse pregnancy outcomes in Northern Tanzania: a cross-sectional study

Background: For the past two decades, studies have investigated the relationship between periodontal disease and adverse pregnancy outcomes such as pre-eclampsia, preterm birth, low birth weight and preterm premature rupture of membranes. Objectives: To determine the prevalence of periodontal disease and associated adverse pregnancy outcomes among women delivering at the Kilimanjaro Christian Medical Centre (KCMC). Methods: This cross-sectional study was based on the use of patients\u2019 files, clinical examinations and oral interviews with mothers who delivered at the KCMC. Pregnant women with singleton babies (N=1117) who delivered at the KCMC were recruited for the study. Intra-oral examination was performed within five days of birth. The Community Periodontal Index was used to assess periodontal disease Results: The prevalence of periodontal disease was 14.2%. Periodontal disease was significantly associated with higher odds of pre-eclampsia [adjusted Odds Ratio 95% Confidence Interval (aOR=4.12;95%CI:2.20-7.90)], low birth weight (aOR=2.41;95%- CI:1.34-4.33) and preterm birth (aOR=2.32;95%CI:1.33-4.27). There was no significant association between periodontal disease and preterm premature rupture of membranes (aORs 1.83;95%CI:0.75-4.21) and eclampsia (3.71;95%CI:0.80-17.13). Conclusion: Maternal periodontal disease is a potential independent risk indicator for pre-eclampsia, low birth weight, and preterm birth. Periodontal assessment and therapy should form part of the preventive antenatal care provided to women in developing countries

Outstanding Methane Oxidation Performance of Palladium-Embedded Ceria Catalysts Prepared by a One-Step Dry Ball-Milling Method

By carefully mixing Pd metal nanoparticles with CeO2 polycrystalline powder under dry conditions, an unpredicted arrangement of the Pd-O-Ce interface is obtained in which an amorphous shell containing palladium species dissolved in ceria is covering a core of CeO2 particles. The robust contact that is generated at the nanoscale, along with mechanical forces generated during mixing, promotes the redox exchange between Pd and CeO2 and creates highly reactive and stable sites constituted by PdOx embedded into CeO2 surface layers. This specific arrangement outperforms conventional Pd/CeO2 reference catalysts in methane oxidation by lowering light-off temperature by more than 50°C and boosting the reaction rate. The origin of the outstanding activity is traced to the structural properties of the interface, modified at the nanoscale by mechanochemical interaction.Postprint (author's final draft

Methanol steam reforming behavior of sol-gel synthesized nanodimensional CuxFe1-xAl2O4 hercynites

This work reports the outstanding catalytic activity behavior of sol-gel synthesized nanostructured CuxFe1-xAl2O4 (0.3¿=¿x¿=¿0.8; named as CuFeAln, where n¿=¿30, 40, 50, 60, 70 and 80) hercynites towards methanol steam reforming (MSR) for hydrogen generation. Based on the durability studies, we had categorized the higher Cu-doped hercynites (CuFeAl70 and CuFeAl80) as the more effective in regard to activity and stability (maintenance of a methanol conversion of ~80% with low CO selectivity of 2% after 50¿h of continuous operation at 275¿°C for CuFeAl80) when compared with the lower Cu-doped counterparts (CuFeAl30 and CuFeAl40). The specific surface area of all the materials was about 50 m2¿g-1 and they had similar reduction characteristics as obtained from H2-TPR analysis. The lower reducibility below 280¿°C of CuFeAl70 and CuFeAl80 was correlated with the higher stability of these samples during time on stream operation. The powder XRD analyses had shown pure phase hercynite formation with the gradual increase of Cu-doping, while there occurred a phase segregation in the reforming atmosphere leading to the formation of metallic copper. High resolution microstructural analyses had confirmed single phase hercynite formation at nanoscale and a reduction of copper subsequent to ageing as well as certain growth of the copper metal particles (from ~5¿nm to ~8¿nm) corroborating the XRD studies. The surface features from in-situ XPS had also suggested formation of reduced copper species, which was much lower for the higher Cu-doped samples. Cu K edge XANES spectral analyses also pointed to lower occurrence of reduced copper in the aged samples of higher Cu-doped hercynites. The experimental findings had been explained on the basis of partial breakdown of the spinel lattice structure leading to the formation of CuO, followed by its reduction to metallic copper nanocrystallites in the MSR atmosphere. A definite ratio of the reduced to oxidized copper species was maintained with time on stream and this caused nearly stable conversion behavior of the catalysts in methanol steam reforming.Peer ReviewedPostprint (author's final draft