Comparative evaluation of selected starches as adsorbent for Thin-layer Chromatography

Purpose: A variety of tested organic and inorganic adsorbents are available today specifically for thin-layer chromatography. The most commonly used is silica gel which is an inorganic adsorbent. Organic substances like cellulose, polyethylene are also used. All these are imported into Nigeria and are unhealthy for economic policies. Most commonly used adsorbent may not be easy to produce locally, but starch, which is a very common product, can be made very readily available. Method: Comparative tests were carried out on cassava, guinea corn and irish potato starches to evaluate and determine suitability as adsorbents for thin-layer chromatography. The starches were used in their natural forms and various modified forms:- formamide, paraffin-impregnated forms and derivatized forms so as to exhibit different properties using different solvent systems to separate different classes of compounds namely alkaloids, amine acids, lipids and steroids with silica gel as standard. Results: The results obtained have proved starch to be a suitable adsorbent both in its naturally occurring and modified forms. Good separations of amino acids and steroids were obtained on natural layers when compared with silica gel, while alkaloids on formamide-impregnated layers and lipids on paraffin-impregnated layers also gave encouraging results. The acetylated starch by suitable modification should produce good results. Conclusion: The suitability of natural starches and its modifications as adsorbents for TLC has thus been established and seems very promising for future use. Keywords: Starch, cassava, guinea corn, Irish potato, adsorbent, thin-layer chromatography. > Tropical Journal of Pharmaceutical Research Vol. 4 (1) 2005: pp. 331-33

In vitro Antimicrobial Activity of the Extract of Mitracarpus scaber Leaves Formulated as Syrup

Purpose: To formulate the crude extract of the leaves of Mitracarpus scarber “Zucc” as a syrup. Method: The antimicrobial activity of the formulation was assessed using agar plates and concentrations of the extract varying between 25mg/ml and 300mg/ml to determine the minimum inhibitory concentration at 37oC against bacterial and fungal organisms namely, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Sarcina lutea, Candida albicans and Klebsiella pneumoniae. Result: The growth of Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans was inhibited by the formulation at a minimum inhibitory concentration of 75mg/ml. Pseudomonas aeruginosa, and Sarcina lutea resisted all the concentrations of the formulation used. The presence of sucrose in the formulation rendered the formulation pleasant to taste. Conclusion: The extract from the leaves of Mitracarpus scarber “Zucc” can be formulated into a pleasantly tasting oral dosage form despite its bitter taste. Keywords: Antimicrobial, Mitracarpus scaber, syrup, formulation, minimum inhibitory concentration > Tropical Journal of Pharmaceutical Research Vol. 6 (1) 2007: pp. 679-68

Pharmacognostic evaluation of the leaves of Mitracarpus scaber Zucc (Rubiaceae)

Purpose: The methanolic extract and isolated constituents of Mitracarpus scaber Zucc have been reported to exhibit hepatoprotective, antibacterial and antimycotic activities. Establishment of Pharmacognostic profile of the leaves will assist in standardization for quality, purity and sample identification. Method: Evaluation of the fresh, powdered and anatomical sections of the leaves were carried out to determine the macromorphological, micromorphological, chemomicroscopic, numerical and phytochemical profiles. Results: Macro - and microscopical studies indicated presence of simple leaf whorled arrangement, an entire margin with lanceolate shape, acute apex and base, parallel venation, thin and wavy anticlinal walls with numerous calcium oxalate crystals. Stomata arrangement was anomocytic with numerous covering trichomes on both surfaces. Chemomicroscopic characters present include lignin, starch, cellulose, mucilage and calcium oxalate crystals while phytochemical evaluation revealed the presence of alkaloids, tannins, cardiac glycosides and saponins. The investigations also included numerical and quantitative leaf microscopy. Conclusion: These findings should be suitable for inclusion in the proposed Pharmacopoeia of Nigerian Medicinal plants. Keywords: Mitracarpus scaber, Pharmacognostic evaluation, Pharmacopoeia. Tropical Journal of Pharmaceutical Research Vol. 6 (4) 2007: pp. 849-85

Effects of Increasing Chitosan Nanofibre Volume Fraction on the Mechanical Property of Hydroxyapatite

This work attempted to synthesize chitosan (CH) nanofibre from crab shell and hydroxyapatite, HA, from limestone with the objective of studying the effects of increasing volume fraction of chitosan nanofibre on the mechanical properties of HA. Mechanical characterization of different fraction composite was carried out to study the effects of increasing volume fraction of chitosan nano fibre on the mechanical properties of HA. In addition, surface characterization of the composite was carried out using Fourier Transform Infrared Spectrometry, FT-IR. Results obtained indicated that the optimum mechanical properties were obtained at a volume fractions of 30: 70, CH: HA respectively; average compressive strength of 10.12 MPa; average tensile strength of 173.9 MPa; average hardness value of 420.80 HV; average fracture toughness of 14.72 MPa.m1/2; average elastic modulus of 0.1583 GPa and average bending strength of 157.96 MPa were obtained for this optimum volume fractions. Increasing volume fractions of chitosan nanofibre was therefore found to result in decrease in compressive strength, hardness and elastic modulus of HA while its tensile strength, bending strength and fracture toughness increased. The FTIR revealed that possible interaction between the NH2 group and the primary and secondary –OH group of CH with Ca2+ (metal coordination interaction) of HA might be responsible for the higher mechanical property of HA. In conclusion, it was found that increasing chitosan volume fraction in chitosan/HA composite results in increasing strength of hydroxyapatite, consequently enhancing its load bearing ability

Extraction of a low grade zinc ore using gravity and froth flotation methods

Extraction of low grade zinc ore found in Gumau- Toro town was carried out using gravity and froth flotation methods. Analysis of the chemical composition reveals that the crude ore contains 20.20% Zinc and other related minerals such as  66.72% SiO2, 2.36%.Pb, 16.62%Fe, 0.001%Ag, these are impurities that  hindered the grade of zinc in this ore from appreciating. Fractional and grain sieve size results revealed that the liberation size of the ore is at -355+250μm assaying 32.41%Zn. At this liberation sieve size, the low grade zinc ore was subjected to four different beneficiation methods using five kilograms (5kg) each as charge into  Wilfley shaking Table, Humphrey spiral concentrator, Air floating Machine and one kilogram (1kg) for froth flotation. Resulting products (concentrate and tailing) from these processes were analyzed using instrumentation method. Percentage recovery of each applied process was calculated. This was used to ascertain that the use of froth flotation that gives 74.32%Zn at a recovery of 84.62% stands out the best method for zinc extraction towards value addition to the low grade crude zinc ore. ©JASEMKey words: Extraction, Upgrading, Gravity, Froth flotation, Mineral, Fractional  analysis.

Investigation of Physicochemical and Mechanical Property of UTAN Granites for Building Applications

The granite formation for production of dimension stone blocks at Utan was investigated in three different locations A, B and C in a view to examine the physical properties of Utan granite using saturation and Buoyancy technique; evaluate some of its mechanical properties; determine its rate of emission of radioactive elements with Geiger Muller Counter; examine its polish-ability; and carry out chemical analysis of the granite samples with the aid of energy dispersive x-ray florescence (ED-XRF). The average porosity obtained is 0.53, 1.08; and 0.86 while the respective average density of 2.58, 2.62 and 2.60 g/cm3 were obtained for A, B and C. The compressive strength of 207.5, 204.6 and 203.4 MPa; and tensile strength of 13.86, 13.68 and 13.60 MPa were obtained for A, B and C respectively. Rockwell hardness values obtained are 89.0, 89.9 and 86.6 while the morh’s hardness values are 6.90, 6.96 and 7.03 respectively for sample A; B and C. The impact values obtained are 0.089, 0.092 and 0.094 for A, B and C respectively. The radioactive rates of samples A, B and C are 6.42, 8.86 and 8.16 Mrem respectively. Sample B is observed to be more radioactive. Both samples are polish able. Conclusively, the three tested granite rocks have suitable physical and mechanical properties that meant the requirement for building purposes; from the polish-ability test, it shows that the three (3) granite outcrops are suitable for the production of granite tiles; countertops; slabs. The chemical analysis revealed that the granite is dominated by quartz (SiO2) which contributes greatly to the hardness of the rock. Also from the radioactive test, the granite samples proved conclusively that the rate of radiation found occasionally in a slab of granite is not harmful to humans when exposed to it. Hence, granite the formation of Utan will be a good building stone material

Comparative Study of Local Mining Methods and Assay of Cassiterite with other Alluvial Mineral Deposits in Kuru-Jantar, Plateau State, Nigeria

This research attempt to investigate and compare the local mining methods of cassiterite in Kuru-Jantar with the view to determine the mean recovery per day using statistical approach, separating the valuable minerals through the gravity and magnetic techniques, determine the grade of cassiterite (tin oxide) with the aid of volumetric and energy dispersive x-ray florescence (XRF) analyses; and determine the percentage composition of metals in cassiterite as well as its associate ores with the aid of (XRF). Sub-surface (lotto) and surface (Hand paddock) mining methods were carried out and the respective recovery from each of the method was subjected to processing, sampling and assaying to determine the quantity, quality (grade) and expected smelter-yield. The mean recoveries per day are 14.48 and 11.28 kg/day for lotto and paddock mining methods respectively. The burretting differential obtained for the lotto and paddock methods are 18.80 – 19.80 and 18.80 – 19.30 respectively while their respective percentage tin metal burretted are 90.40 – 97.83 and 92.51 – 97.80 %. The recoveries from the magnetic and gravity separations are 10.91 kg and 9.06 kg for lotto and paddock methods respectively. The XRF analysis gave 68.69 and 66.462 % Sn respectively for the lotto and paddock while the assaying of other associate minerals are 40.4 % Nb; 26.5 % Fe; 22.3 % Ti; 2.5 % Ta; 2.3 % Sn; and 5.1 % W for the paddock and 37.6 % Nb; 24.8 % Fe; 21.5 % Ti; 2.3% Ta; 5.8 % Sn; and 4.9 % W for lotto. It can be observed that the lotto mining method has the highest recovery per day and hence, gives better recovery than paddock mining method. Lotto mining was found to yield higher grade tin-ore concentrate than the hand paddock mining method in both volumetric and XRF analyses but hand paddock gives higher quantity and more associate minerals. It was also found out that the lotto method is more risky and life threatening than paddock mining while the paddock mining practices render more danger to environment than the lotto mining

Integrating Malaria Surveillance with Climate Data for Outbreak Detection and Forecasting: the EPIDEMIA System

Background: Early indication of an emerging malaria epidemic can provide an opportunity for proactive interventions. Challenges to the identification of nascent malaria epidemics include obtaining recent epidemiological surveillance data, spatially and temporally harmonizing this information with timely data on environmental precursors, applying models for early detection and early warning, and communicating results to public health officials. Automated web-based informatics systems can provide a solution to these problems, but their implementation in real-world settings has been limited. Methods: The Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system was designed and implemented to integrate disease surveillance with environmental monitoring in support of operational malaria forecasting in the Amhara region of Ethiopia. A co-design workshop was held with computer scientists, epidemiological modelers, and public health partners to develop an initial list of system requirements. Subsequent updates to the system were based on feedback obtained from system evaluation workshops and assessments conducted by a steering committee of users in the public health sector.Results: The system integrated epidemiological data uploaded weekly by the Amhara Regional Health Bureau with remotely-sensed environmental data freely available from online archives. Environmental data were acquired and processed automatically by the EASTWeb software program. Additional software was developed to implement a public health interface for data upload and download, harmonize the epidemiological and environmental data into a unified database, automatically update time series forecasting models, and generate formatted reports. Reporting features included district-level control charts and maps summarizing epidemiological indicators of emerging malaria outbreaks, environmental risk factors, and forecasts of future malaria risk. Conclusions: Successful implementation and use of EPIDEMIA is an important step forward in the use of epidemiological and environmental informatics systems for malaria surveillance. Developing software to automate the workflow steps while remaining robust to continual changes in the input data streams was a key technical challenge. Continual stakeholder involvement throughout design, implementation, and operation has created a strong enabling environment that will facilitate the ongoing development, application, and testing of the system

Africa needs climate data to fight disease

Climate variability and change are a major concern for public health in Africa. The livelihoods of hundreds of millions of people there are dependent on rain-fed agriculture and seasonal water resources. Poor rural communities also suffer from under-nutrition and bear the greatest burden of infectious diseases and natural disasters while having the least access to public-health services. Many of Africa’s most important cities are on the coast and at risk of sea level rise. Without adequate infrastructure they are vulnerable to poor sanitation during floods and shortages of drinking water and loss of hydroelectric power during droughts. Rising temperatures, air pollutants and dust threaten to increase heat stress and respiratory disease