6 research outputs found

    X-ray Spectroscopy of a Rare-Earth Molecular System Measured at the Single Atom Limit in Room Temperature

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    We investigate the limit of X-ray detection at room temperature on rare-earth molecular films using lanthanum and a pyridine-based dicarboxamide organic linker as a model system. Synchrotron X-ray scanning tunneling microscopy is used to probe the molecules with different coverages on a HOPG substrate. X-ray-induced photocurrent intensities are measured as a function of molecular coverage on the sample allowing a correlation of the amount of La ions with the photocurrent signal strength. X-ray absorption spectroscopy shows cogent M4,5 absorption edges of the lanthanum ion originated by the transitions from the 3d3/2 and 3d5/2 to 4f orbitals. X-ray absorption spectra measured in the tunneling regime further reveal an X-ray excited tunneling current produced at the M4,5 absorption edge of La ion down to the ultimate atomic limit at room temperature.Comment: 19 pages, 4 figure

    Nitric Oxide and Pre-Eclampsia: A Comparative Study in Ghana

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    BACKGROUND: Preeclampsia is one of the commonest aetiologies of foetal and maternal mortality and morbidity. Though common, the aetiology of preeclampsia has remained unknown with several inconclusive theories surrounding the disease. Recent studies have implicated vascular endothelial dysfunction and possibly nitric oxide in preeclampsia.AIM: To compare plasma nitric oxide levels in pre-eclampsia and healthy pregnant women in a large tertiary hospital in Ghana.METHODS: This was a case-control study conducted among pre-eclampsia and healthy pregnant women in Korle-Bu Teaching Hospital over a four-month period. Thirty (30) pre-eclamptic and 30 healthy pregnant women aged 18-35 years with over 30 weeks’ gestation were consecutively recruited into the study after obtaining informed consent. Plasma nitric oxide levels were determined using the Griess Reagent system.  Data were analysed using Statistical Package for the Social Sciences (SPSS) software version 20.0 and results were compared using the independent t-test. A P-value of ≤ 0.05 was considered statistically significant.RESULTS: The parity and body mass index (BMI) of the participants were similar. There was a significant difference in the blood pressure of the pre-eclamptic compared to healthy pregnant women. There was no statistically significant difference (P-value = 0.160) in the plasma levels of nitric oxide in pre-eclamptic (Mean = 1178.78; SD = 89.70 nM) compared to healthy pregnant women (Mean = 1365.43; SD = 95.46 nM).CONCLUSION: Plasma nitric oxide levels may not play a significant role in the aetiology of pre-eclampsia

    Serum Calcium and Magnesium Levels in Normal Ghanaian Pregnant Women: A Comparative Cross-Sectional Study

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    BACKGROUND: Pregnancy is described as a normal physiologic state associated with various biochemical changes. Magnesium and calcium are essential macronutrients required for foetal growth. Complications associated with their deficiency during normal pregnancy include; low neonatal birth weight, pre-eclampsia, eclampsia and preterm labour. Changes in serum levels of magnesium and calcium in normal pregnancy have not been extensively studied among Ghanaian women. AIM: To determine the variation in serum magnesium and calcium levels with gestational age in normal pregnancy in Ghanaian women. METHODS: A hospital-based comparative cross-sectional study was conducted among 32 normal non-pregnant women (Group A) and 100 normal pregnant women (Group B) attending the clinic at the Korle-Bu Teaching hospital. The group B pregnant women were further divided into Group B1 (n = 33), Group B2 (n = 37) and Group B3 (n = 30) based on their pregnancy gestation as first, second and third trimester respectively. Blood samples were obtained from the antecubital vein of subjects and total serum calcium, magnesium, protein and albumin were estimated. Data obtained were analysed using SPSS for windows version 20. Analysis of variance (ANOVA) was employed to determine the statistical differences between the groups. A p-value of ≤ 0.05 was considered significant. RESULTS: Mean serum total calcium and magnesium in first, second and third trimester normal pregnant women were 2.14 ± 0.16, 2.13 ± 0.44, 2.13 ± 0.35 mmol/L and 0.77 ± 0.11, 0.77 ± 0.16 and 0.76 ± 0.14 mmol/L respectively. Mean serum total calcium and magnesium levels in non-pregnant women were 2.20 ± 0.16 and 0.80 ± 0.10 mmol/L respectively. There was a statistically non-significant difference in serum total calcium and magnesium between non-pregnant and normal pregnant women, with p-values of 0.779 and 0.566 respectively. Mean total serum protein and albumin in first, second and third-trimester normal pregnant women were 68.42 ± 10.37, 70.46 ± 6.84, 66.70 ± 7.83 g/L and 39.92 ± 3.22, 40.75 ± 8.06, 38.26 ± 3.02 g/L respectively. Mean total serum protein and albumin in non-pregnant women were 73.13 ± 7.02 and 42.94 ± 3.03 g/L respectively. Mean total serum protein and albumin levels were lower in pregnant women as compared to non-pregnant women with the difference being significant in the third trimester (p-values of 0.012 and 0.002). CONCLUSION: Total serum calcium and magnesium levels in normal pregnancy were non-significantly lower compared to non-pregnant women in Ghana. There was a reduction in total serum protein, and albumin levels during pregnancy with a significant reduction noticed during the third trimester compared to the non-pregnant state

    Serum sodium and potassium levels in preeclampsia: A case-control study in a large tertiary hospital in Ghana

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    Background: Preeclampsia remains a poorly understood complication of pregnancy affecting 5–14% pregnancies worldwide. Recent studies indicate that serum electrolytes may play a role in preeclampsia since it is a vascular endothelial disorder. Aim: To compare serum sodium and potassium levels between preeclamptics and normotensive pregnant women in a tertiary hospital in Ghana. Methods and materials: This was a case-control study consisting of 30 preeclamptics and 30 normotensive pregnant women recruited consecutively at their first third trimester pre-natal visit at Korle-Bu Teaching Hospital. Serum sodium and potassium were analysed using Sherwood Flame Photometer (Model 420 Sherwood Scientific Ltd, UK). Analysis was done using Statistical Package for Social Sciences (SPSS®) software version 20.0 and presented as means (standard deviation). A p-value of ≤0.05 was judged significant. Results: There was a significantly reduced (p < 0.001) serum sodium levels in preeclamptics (mean = 136.13; SD = 4.17 mmol/L) compared to normotensive pregnant women (mean = 142.17; SD = 5.66 mmol/L). There was a significantly reduced (p < 0.001) serum potassium levels in preeclamptics (mean = 3.45; SD = 0.54 mmol/L) compared to normotensive pregnant women (mean = 3.98; SD = 0.36 mmol/L). Conclusion: The reduced levels of serum sodium and potassium in preeclampsia as compared to normotensive pregnant women, suggests that changes in these electrolytes may be associated with preeclampsia

    Serum nitric oxide levels in healthy pregnant women: a case- control study in a tertiary facility in Ghana

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    Abstract Background Pregnancy is associated with significant changes in maternal cardiovascular system which regulates oxygen and nutrient supply to the growing foetus. Nitric oxide, a physiologic vascular smooth muscle relaxant regulates blood flow and therefore may play a role in the cardiovascular changes in pregnancy. The study aimed to determine the levels and changes in maternal serum nitric oxide levels during healthy pregnancy. Methods A case-control study was conducted among 32 healthy non-pregnant women as controls and 100 healthy pregnant women (consisting of 33 first trimester, 37 s trimester, and 30 third trimester) as cases. Subjects were consecutively recruited into the study after obtaining an informed consent and meeting the inclusion criteria. Griess Reagent method was used to determine serum nitric oxide levels. Results There were no statistically significant difference in the ages and parity of recruited cases and controls. Mean arterial blood pressures were significantly lower (p = 0.009) and serum nitric oxide levels were significantly higher (p < 0.001) in healthy pregnant women compared to healthy non-pregnant women. There was a non-significant progressive increase in serum nitric oxide levels during healthy normal pregnancy. Conclusions The finding of a significantly reduced blood pressures and a significant increase in serum nitric oxide levels in healthy pregnancy may suggest a role of nitric oxide in vascular adaptation in pregnancy

    Clinical features of COVID-19 in Ghana : Symptomatology, illness severity and comorbid non-communicable diseases

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    Objective: This analysis described the clinical features of COVID-19 in the early phase of the pandemic in Ghana. Methods: Data were extracted from two national COVID-19 treatment centers in Ghana for over 11 weeks(from March to May 2020). Descriptive and inferential statistics were performed. Modified Ordered Logistic and Negative Binomial Regression analysis were applied to establish factors associated with illness severity and Non-communicable Disease (NCDs) counts respectively. All analysis was conducted at the 95% confidence level (p-value ≤ 0.05) using Stata 16. Results: Among the 275 patients, the average age was 40.7±16.4, with a preponderance of males (54.5%). The three commonest symptoms presented were cough (21.3%), headache (15.7%), and sore throat (11.7%). Only 7.6% of the patients had a history of fever. Most patients were asymptomatic (51.65). Approximately 38.9% have an underlying co-morbid NCDs, with Hypertension (32.1%), Diabetes (9.9%), and Asthma (5.2%) being the three commonest. The odds of Moderate/severe (MoS) was significantly higher for those with unknown exposures to similar illness [aOR(95%CI) = 4.27(1.12-10.2)] compared with non-exposure to similar illness. An increased unit of NCD’s count significantly increased the odds of COVID-19 MoS illness by 26%[cOR(95%CI) =1.26(1.09-1.84)] and 67% (adjusting for age) [aOR(95%CI)=1.67(1.13-2.49)]. Conclusion: The presence of cardiovascular co-morbidities dictated the frequency of reported symptoms and severity of COVID-19 infection in this sample of Ghanaians. Physicians should be aware of the presence of co-morbid NCDs and prepare to manage effectively among COVID-19 patients
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