Determination of Levels of Essential and Toxic Heavy Metals in Lentil (Lens culinaris Medik) by Flame Atomic Absorption Spectroscopy

The concentrations of trace essential metals (Co, Cu, Fe, Mn, Ni and Zn) and toxic heavy metals (Cd and Pb) in lentil samples collected from Dejen (East Gojjam), Boset (East Shewa) and Molale (North Shewa), Ethiopia, were determined by flame atomic absorption spectrometry. A wet digestion procedure, using mixtures of HNO3, HClO4 and H2O2 was developed for the decomposition of powdered lentil samples. The accuracy of the method was checked by the standard addition method. The contents of heavy metals in lentil samples were in the range of 0.009-0.013 for Cd, 0.285-0.360 for Co, 0.226-0.282 for Cu, 9.17-11.91 for Fe, 6.7-8.2 for Mn, 0.120-0.244 for Ni, 0.142-0.176 for lead and 8.62-10.03 for Zn, all in mg/100 g. The results were compared with values reported in the literature

Generic but Expensive: Why Prices Can Remain High for Off-Patent Drugs

Brand-name prescription drugs are sold at extremely high prices in the US because patents and other market exclusivities provided by the government allow manufacturers to exclude direct competition. This period of market exclusivity was intended for pharmaceutical manufacturers to recoup costs associated with research and development of those products and make profits. The other intended outcome of this system is that the market exclusivity period for brand-name drugs should be self-limited, with competition being able to flourish after the market exclusivities end. Such competition has been most effectively supplied by generic drug manufacturers that produce Food and Drug Administration (FDA)-approved bioequivalent versions of the brand-name product. The market entry of these generic drugs—with market uptake augmented by automatic substitution of brand-name prescriptions at the pharmacy— remains the only market intervention that lowers prescription drug prices consistently and substantially. Generic manufacturers can make their drugs available at considerably lower cost because of various market advantages they have over brand-name drugs. When this process does not operate as intended, drug prices do not fall after market exclusivity expiration, or prices for generic drugs may actually increase. In this paper, we examine the variety of factors that mitigate the cost savings associated with introduction of interchangeable generic drugs, especially older, off-patent drugs. We then consider policy solutions that may help stabilize the generic drug marketplace, diminishing the frequency and impact of generic price increases

Improvement of accession distinctiveness as an added value to the global worth of the yam (Dioscorea spp) genebank

Open Access JournalMisidentification of accessions is a common problem in genebanks. Along the years, mistakes accumulate and this is particularly true when dealing with a large number of accessions requiring annual regeneration. Human errors such as mislabeling or misreading and material mix up during planting or storage are the main causes for misidentification of accessions. The international collection of yam, maintained at IITA, has accumulated ‘non true to type’ accessions along the years. In the present study, 53 morphological descriptors were used to detect uniformity of individuals within accessions of the yam gene bank collection i.e. agro morphological mismatch between individual plants of the same accession. Based on a similarity matrix, individual pairs with less than 0.90 similarity coefficients, which varies in six descriptors and more, were considered as distinct and mismatched, whereas those that had similarity coefficients greater than or equal to 0.90 were considered as clones from the same parent. Overall, 20.60% of the total 3156 accessions were found not true to type i.e., misidentified individuals. The descriptive analysis shows that morphological traits like distance between lobes, upward folding of leaf along main vein, young stem color, old stem color, leaf shape, leaf density and plant vigor are the most discriminative descriptors for individual identification within accession. Some other traits were also found species specific and they may aid in distinguishing misidentifications between species

Africa RISING Ethiopian Highlands Integrated Landscape Management Exchange Visit, 4-7 May 2016

United States Agency for International Developmen

Sensitive electrochemical determination of ethambutol in pharmaceutical formulation and human urine at nickel nanoparticles/electrochemically reduced graphene oxide modified electrode

This paper describes the application of nickel nanoparticles decorated electrochemically reduced graphene oxide modified glassy carbon electrode (NiNPs/ERGO/GCE) for the determination of ethambutol (ETB), an anti-Mycobacterium tuberculosis drug. The modified electrode showed remarkable electrocatalytic properties accompanied with a significant enhancement in the peak current response towards ETB compared to the bare electrode. The results showed that the composite modified electrode played a significant catalytic role due to the synergetic effect of NiNPs and ERGO. The NiNPs/ERGO modified electrode demonstrated excellent square wave voltammetric response towards ETB determination at the NiNPs/ERGO/GCE in the range 0.05‒100 µM. The sensor demonstrated outstanding sensitivity towards ETB determination with limit of detection (LOD) and limit of quantification (LOQ) of 0.023 and 0.075 µM, respectively. The developed sensor was effectively validated for real sample study using drug formulation and urine samples which showed an acceptable recovery (99.6‒109%). The electrode also exhibited good precision (RSD < 1%, n = 20), reproducibility (RSD < 1.9%, n = 3), long-term stability (92% of its initial response after two weeks) and selectivity towards interfering substances in the determination of ethambutol.               KEY WORDS: Ethambutol, Glassy carbon electrode, Square wave voltammetry, Electrochemically reduced graphene oxide, Nickel nanoparticles Bull. Chem. Soc. Ethiop. 2019, 33(2), 215-228.DOI: https://dx.doi.org/10.4314/bcse.v33i2.

Rapid In-Vitro Inactivation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Using Povidone-Iodine Oral Antiseptic Rinse

Purpose To investigate the optimal contact time and concentration for viricidal activity of oral preparation of povidone‐iodine (PVP‐I) against SARS‐CoV‐2 (‘corona virus’) to mitigate the risk and transmission of the virus in the dental practice. Materials and Methods The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) USA‐WA1/2020 strain, virus stock was tested against oral antiseptic solutions consisting of aqueous povidone‐iodine (PVP‐I) as the sole active ingredient. The PVP‐I was tested at diluted concentrations of 0.5%, 1%, and 1.5%. Test media without any virus was added to 2 tubes of the compounds to serve as toxicity and neutralization controls. Ethanol (70%) was tested in parallel as a positive control, and water only as a negative control. The test solutions and virus were incubated at room temperature (22 ± 2 °C) for time periods of 15 and 30 seconds. The solution was then neutralized by a 1/10 dilution in minimum essential medium (MEM) 2% fetal bovine serum (FBS), 50 µg/mL gentamicin. Surviving virus from each sample was quantified by standard end‐point dilution assay and the log reduction value (LRV) of each compound compared to the negative (water) control was calculated. Results PVP‐I oral antiseptics at all tested concentrations of 0.5%, 1%, and 1.5%, completely inactivated SARS‐CoV‐2 within 15 seconds of contact. The 70% ethanol control group was unable to completely inactivate SARS‐CoV‐2 after 15 seconds of contact, but was able to inactivate the virus at 30 seconds of contact. Conclusions PVP‐I oral antiseptic preparations rapidly inactivated SARS‐CoV‐2 virus in vitro. The viricidal activity was present at the lowest concentration of 0.5 % PVP‐I and at the lowest contact time of 15 seconds. This important finding can justify the use of preprocedural oral rinsing with PVP‐I (for patients and health care providers) may be useful as an adjunct to personal protective equipment, for dental and surgical specialties during the COVID‐19 pandemic

Computational studies on heterogenization of homogeneous catalyst of iron(III), nickel(II) and copper(II) N,N′-disalicylidene-1,2-phenylenediamine complex

Density functional theory (DFT) calculations were carried out on iron(III), nickel(II) and copper(II) complexes of N,N′-ethylenebis(salicylimine) both at molecular level (isolated complexes) and encapsulated in a zeolite framework to investigate changes that occur in their geometrical and electronic parameters as well as in their reactivity and stability. The computational results showed that the zeolite encapsulated metal complexes have higher reactivity and less stability as compared to the isolated metal complexes.               KEY WORDS: Density functional theory, N,N′-ethylenebis(salicylimine), Computational studies, Heterogenization, Electronic parameters Bull. Chem. Soc. Ethiop. 2019, 33(1), 91-102DOI: https://dx.doi.org/10.4314/bcse.v33i1.