Voltammetric determination of tinidazole in pharmaceutical tablets using carbon paste electrode

Cyclic voltammetry was used to study the electrochemical behavior of tinidazole at carbon paste electrode. Tinidazole showed an irreversible reduction peak at about -440 mV. The differential pulse voltammetric peak current of tinidazole showed linear dependence on concentration in the range 5.0-200 μM with LOD and LOQ of 5.1 10-7 and 1.7 10-6 μM, respectively. Relative to most of the reported works on the determination of tinidazole, the developed method using carbon paste electrode which is an environmentally friendly, cheap, and simple working electrode exhibited linear dependence of peak current on concentration in the lower concentration region with relatively low LOD. Excellent recovery results with low % RSD for spiked standard tinidazole in tablet samples showed the potential applicability of the developed method for the determination of tinidazole in real samples. KEY WORDS: Carbon paste electrode, Differential pulse voltammetry, Tinidazole, Pharmaceutical tablets Bull. Chem. Soc. Ethiop. 2016, 30(1), 1-12.DOI: http://dx.doi.org/10.4314/bcse.v30i1.

Additive Main Effects and Multiplicative Interaction Analysis of Coffee Germplasms from Southern Ethiopia

Additive main effects and multiplicative interaction (AMMI) analysis is a recently recommended effective method to study the genotype by environment (GxE) interaction pattern of multi-environment varietal trials. This work deals with modeling and examining the GxE interaction pattern of the multi-environment trials of 43 genotypes and eight environments from Southern Ethiopia coffee (Coffea Arabica L.) collections using a randomized complete block design (RCBD) with four replications. The work further attempts to predict yield based on the ammi model and evaluate and recommend high performing and adaptable varieties. The AMMI model with the first two interaction principal component axes (AMMI2) is found to be appropriate and parsimonious for the data. Environments e5, e6, e7, e8 and e3 are found to be high potential environments, where genotypes having high-yield (greater than 14 qt/ha) and resistant to Coffee Berry Disease (CBD) are associated. Among the 43 genotypes, 1, 9, 2, 3, 32, 12 and 25 are found to have the best performance with 3, 32, 12 and 25 being highly stable. Among the high-yielding genotypes, 33, 4, 23, 34 and 27 are found to be highly unstable and particularly adapted to environments 5, 6, 7 and 3, respectively

Anatomical variations and distributions of obturator nerve on Ethiopian cadavers

Variations in anatomy of the obturator nerve are important to surgeons and anesthesiologists performing surgical procedures in the pelvic cavity, medial thigh and groin regions. They are also helpful for radiologists who interpret computerized imaging and anesthesiologists who perform local anesthesia. This study aimed to describe the anatomical variations and distribution of obturator nerve. The cadavers were examined bilaterally for origin to its final distribution and the variations and normal features of obturator nerve. Sixty-seven limbs sides (34 right and 33 left sides) were studied for variation in origin and distribution of obturator nerve. From which 88.1% arises from L2, L3 and L4 and; 11.9% from L3 and L4 spinal nerves. In 23.9%, 44.8% and 31.3% of specimens the bifurcation levels of obturator nerve were determined to be intrapelvic, within the obturator canal and extrapelvic, respectively. The anterior branch subdivided into two, three and four subdivisions in 9%, 65.7% and 25.4% of the specimens, respectively, while the posterior branch provided two subdivisions in 65.7% and three subdivisions in 34.3% of the specimens. Hip articular branch arose from common obturator nerve in 67.2% to provide sensory innervation to the hip joint. Accessory obturator nerve was not observed at all in this study. Key words: Variations, obturator nerv

Aspergillus species and aflatoxin contamination in pepper (Capsicum annuum l.) in West Gojjam, Ethiopia

Pepper (Capsicum annuum L.) is an important spice and source of income for smallholder producers in Ethiopia. Since the larger proportion is for the market, it takes a significant share of the national income from export commodity. However, often the product was rejected by some of the European Union markets due to the maximum aflatoxin level accumulations beyond their acceptable limits. So, the present study was carried out to highlight the importance of Aspergillus species invasion in pepper, and levels of aflatoxin contamination at maturity in the field (pod form), farmers' storage and local market (powder form) in West Gojjam, Ethiopia. A total of 135 pepper samples were collected from three districts of West Gojjam (Burie, Jabitehnan, and Fnoteselam), Ethiopia for fungal and aflatoxin analysis. The producers used a pre-validated structured questionnaire to obtain information on pepper production practices. Aspergillus species isolates were recovered using potato dextrose agar (PDA) medium and counting was through dilution method (cfu g-1). The pepper pods were ground to a fine powder for aflatoxin analysis using Enzyme-Linked Immunosorbent Assay (ELISA). The prevalence of infected samples revealed that, pre-harvest samples (51%) were less infected by Aspergillus species, compared to local markets (65 %) and storage (79 %). Aspergillus flavus species were recovered in pre-harvest samples, whilst A. niger were found in local market samples. Aflatoxin contamination at pre-harvest, storage, and local market were 10, 47, and 42 % with levels which ranged from non-detected to 10.6, 0.3 - 17.1 and 3.1 - 19.2 ppb, respectively. The mean aflatoxin concentration detected from storage samples (10.6 ppb) and local market (12.6 ppb) were found to be above the tolerable limits set by EU (5 ppb) in pepper products. From the findings in this study, proper drying, physical separation of molded pods and use of clean storage structures should be implemented along the production chain in order to reduce aflatoxin contamination in pepper in Ethiopia

Assessment of climate change impact on hydrological extremes in two source regions of the Nile River Basin

The potential impact of climate change was investigated on the hydrological extremes of Nyando River and Lake Tana catchments, which are located in two source regions of the Nile River basin. Climate change scenarios were developed for rainfall and potential evapotranspiration (ETo), considering 17 General Circulation Model (GCM) simulations to better understand the range of possible future change. They were constructed by transferring the extracted climate change signals to the observed series using a frequency perturbation downscaling approach, which accounts for the changes in rainfall extremes. Projected changes under two future SRES emission scenarios A1B and B1 for the 2050s were considered. Two conceptual hydrological models were calibrated and used for the impact assessment. Their difference in simulating the flows under future climate scenarios was also investigated. <br><br> The results reveal increasing mean runoff and extreme peak flows for Nyando catchment for the 2050s while unclear trend is observed for Lake Tana catchment for mean volumes and high/low flows. The hydrological models for Lake Tana catchment, however, performed better in simulating the hydrological regimes than for Nyando, which obviously also induces a difference in the reliability of the extreme future projections for both catchments. The unclear impact result for Lake Tana catchment implies that the GCM uncertainty is more important for explaining the unclear trend than the hydrological models uncertainty. Nevertheless, to have a better understanding of future impact, hydrological models need to be verified for their credibility of simulating extreme flows

Effect of side chain length on the stability and structural properties of 3-(2’,5’-dialkoxyphenyl)thiophenes: a theoretical study

We report on the effect of the alkoxy chain length on the thermodynamic properties of neutral and the corresponding radical cations of 3-(2’,5’-dibutyloxyphenyl)thiophene (DBOPT), 3-(2’,5’-diheptyloxyphenyl)thiophene (DHOPT), and 3-(2’,5’-dioctyloxyphenyl)thiophene (DOOPT) and their dimers studied by Hartree-Fock (HF) and Density Functional Theory (DFT) methods. The DFT calculations suggest that dimers of the dialkoxyphenylthiophenes with longer side chains are thermodynamically more stable by about 61.39 kJ/mol than the ones with shorter side chains at the radical cation state. The results correlate well with the experimental observations made during the electrochemical synthesis of these polymers from their monomers.KEY WORDS: Density functional theory, Hartree-Fock, DialkoxyphenylthiophenesBull. Chem. Soc. Ethiop. 2010, 24(1), 93-102

Larvicidal effects of Jatropha curcas L. against Anopheles arabiensis (Diptera: Culicidea)

Crude and column chromatographic fractions of methanol leaf extract of Jatropha curcas were tested for their larvicidal activities against laboratory reared late third instar larvae of Anopheles arabiensis. Crude methanol leaf extract of J .curcas had similar larvicidal activity to 0.5 ppm Temephos (positive control) at test concentrations ranging from 125 -1000 ppm while column chromatographic fractions (F1 and F2 ) of the crude methanol leaf extract of J.curcas showed similar larvicidal activities to 0.5 ppm Temephos at 62.5 and 125 ppm test concentrations. Column chromatographic fraction three (F3) showed similar larvicidal activity to 0.5 ppm Temephos at 125 ppm test concentration. The LC50 and LC90 values of crude methanol leaf extract of J.curcas were found to be 92.09 and 241.09 ppm, respectively. Toxic activities of column chromatographic fraction one (F1) (LC50=28.65 ppm; LC90 = 49.20 ppm) were nearly equal to that of column chromatographic fraction two [F2] (LC50= 30.40 ppm; LC90 = 49.80 ppm). Least toxicity on the test larvae was observed by column chromatographic fraction three [F3] (LC50 = 80.70 ppm; LC90 = 123.70 ppm). Thus, the larvicidal activity of crude methanol leaf extract was not due to the synergistic effects of its fractions. Further studies are recommended to identify larvicidal active ingredients from the active column chromatographic fractions of crude methanol leaf extract of J. curcas. Key words: Malaria vector control, Anopheles arabiensis, Botanical larvicides J. curca

Mercury Methylation by Cobalt Corrinoids: Relativistic Effects Dictate the Reaction Mechanism

The methylation of HgII(SCH3)2 by corrinoid‐based methyl donors proceeds in a concerted manner through a single transition state by transfer of a methyl radical, in contrast to previously proposed reaction mechanisms. This reaction mechanism is a consequence of relativistic effects that lower the energies of the mercury 6p1/2 and 6p3/2 orbitals, making them energetically accessible for chemical bonding. In the absence of spin–orbit coupling, the predicted reaction mechanism is qualitatively different. This is the first example of relativity being decisive for the nature of an observed enzymatic reaction mechanism.Of relative importance: The methylation of HgII(SCH3)2 by corrinoid‐based methyl donors proceeds in a concerted manner through a single transition state by transfer of a methyl radical. This reaction mechanism is a consequence of relativistic effects, and constitutes the first example of relativity being decisive for the nature of an enzymatic reaction mechanism. SOC=spin–orbit coupling.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137374/1/anie201606001-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137374/2/anie201606001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137374/3/anie201606001_am.pd

The effect of comorbidities of preeclampsia and eclampsia on maternal and fetal outcome

Background: The aim of this study is to comparatively assess the maternal and fetal outcome in preeclampsia and eclampsia patients with and without comorbidities. The objectives are to assess the comorbidities associated with preeclampsia and eclampsia cases and to find out the effects of the comorbidities of preeclampsia and eclampsia on maternal and fetal outcome. Methods:380 patients who had attended antenatal OPD and emergency labour room of Assam medical college and hospital, Dibrugarh during June 2020 to July 2021 with preeclampsia and eclampsia were selected for present study. Based on relevant history, clinical and laboratory findings, these patients were further evaluated for associated comorbidities. The cases were distributed in the respective comorbidity group. Then the outcome of the mother and the baby were analyzed till the day of discharge in patients without comorbidities and with comorbidities and the same was compared. Results: The eventful maternal (44.1%) and fetal (50.92%) outcome was more in preeclampsia and eclampsia patients with comorbidities than in patients without comorbidities which is statistically significant, (p value=0.029), (p value=0.009) respectively. Conclusions: The effect of preeclampsia and eclampsia itself would adversely affect the pregnancy outcome and the effect is worse when associated with comorbidities. Appropriate prenatal counselling and optimization of the comorbidities is critical for women who are planning pregnancy