Photodynamic therapy: A new light for the developing world

In one article, photodynamic therapy (PDT) was commended as the most suitable method for cancer therapy in the Developing World. PDT is cost effective and simple to use. Unlike chemotherapy, no special training is required for nurses, and no post treatment course in intensive care. No engineer, computerized dosimetry computations, or additional costs for isotope re-treatment are required, as in radiotherapy. There are no blood transfusions, or sophisticated operating theatres, as in surgery. Ironically, it is in the developing world that there appears to be very little awareness of and practice of PDT. Cancer sufferers are thus limited to chemotherapy, radiotherapy and surgery procedures that are relatively complex and costly, without distinctive advantage in cure or palliation. Is it possible that the low level of clinical practice in PDT in the developing world is related to the low level of articulation of what is admittedly a relatively new modality? However, this slow emergence of clinical practice in PDT when compared with advances in its developmental research was also observed in the developed world in the last two centuries or so. The purpose of this article was to advance the articulation of PDT, primarily among basic science researchers, clinicians and clinical scientists in the developing countries. It is also to advance the emerging new frontiers of the clinical applicability of the processes of photodynamic reactions in the fight against infectious disease epidemics, which are a more common occurrence in the developing world countries.Keywords: Photodynamic therapy, developing world, photosensitizer, bacterial infectionAfrican Journal of Biotechnology Vol. 12(23), pp. 3590-359

Heavy metals found at Umzimvubu River Estuary in the Eastern Cape, South Africa

The aim of this research was to detect and measure the concentration of heavy metals found in the water and silt of the Mzimvubu River at Port St Johns in the Eastern Cape. The water from this river estuary is used by the people and animals of that area and is suspected to cause several health conditions. The objective of the research was to undertake a pilot analysis for heavy metals. Atomic Absorption Spectroscopy (AAS) was selected as a tool to determine the concentration of the heavy metals present in the water and sediment samples. Water and sediment samples were collected at the river mouth and 5 kilometers upstream, near the R61 bridge, on either side of the river. The atomic absorption spectrophotometer used to measure the heavy metal concentrations was a Varian Spectra AA 100 equipped with a single slot burner. Measurements were carried out in triplicate. Throughout the study it was evident that there are heavy metals such as lead, cadmium, zinc and nickel in the Umzimvubu River. The bio-accessibility of lead is a concern in view of the fact that it was found in high concentrations. Cadmium contamination was found to be in lower concentrations compared to the South African guidelines. Zinc and nickel were not severe since both were within the WHO and SADWAF guidelines. Therefore, it is concluded that the Umzimvubu River is an intimidation to many living organisms since it contains high concentrations of Lead, significantly higher than the South African guidelines. Severe damage in physical condition could be experienced by the human and animal populations in close proximity to the river. Further and more detailed studies are recommended, including bio-accessibility and bio-accumulation studies.Key words: Mzimvubu river, heavy metals, atomic absoption spectroscopy

Antibacterial effectiveness of Tetradenia riparia extract, a plant traditionally used in the Eastern Cape Province to treat diseases of the respiratory system

The antibacterial properties of Tetradenia riparia, the most frequently used plant by the traditional healer for the treatment of chest and cough related infections was reported in this study. The plant was investigated to evaluate claims made by the users as a remedy for chest and cough related infections. Ten bacterial strains (five gram-positive and five gram-negative) were used for the antibacterial assays. All the extracts showed some activity against the bacteria tested at concentrations ranging from 1.0 to 10.0 mg/ml, with the exception of dichloromethane extract which did not inhibit any of the microorganisms used. The antibacterial properties of the plant extracts were more visible with the gram-positive bacteria while gram-negative bacteria showed more resistance to the treatments especially at low concentration. The resistance of gram-negative bacteria has been attributed to the composition of their cell walls

Flow system, physical properties and heavy metals concentration of groundwater: A case study of an area within a municipal landfill site

Groundwater within the Olusosun landfill site in Lagos Metropolis was evaluated. Previous research on quality parameters of groundwater in the area made use of equipment of low detection capacity for heavy metals concentrations in water. Also, subsurface flow and significant attenuation of leachate due to horizontal distance between wells and landfill site are yet to be technically elucidated. In the present investigation, priority was given to heavy metals as small quantities may build up in human systems to become a significant health hazard. Then analysis was done with Inductively Coupled Plasma Mass Spectrometry (ICP-MS), while Geographical Information Systems (GIS) technique was used for spatial data analysis and management to illustrate localised flow of groundwater. Digital subsurface model of data from 20 drinking-water wells showed that flow directions are north-south, north-west and southeast. The two extremes of the pH for the groundwater are 4.04 and 8.05, indicating slightly acidic to weakly basic water. Total Dissolved Solids (TDS) are positively-strongly correlated with electrical conductivity (EC) in a line of fit TDS = 29.71 EC - 47.9. From the ICP-MS results, Fe concentrations at locations 1, 3 and 4, and Pb concentrations at locations 1, 5, 7, 8, 14 and 16 did not conform to international human-health benchmarks. Generally, the longer the horizontal distance between a well and the landfill site, the lesser its potential for groundwater contamination. This study better clarifies heavy metals concentrations in water, with GIS for satisfactorily display of positional and attribute for groundwater flow in the area

Physico-chemical properties of palm oil from different palm local factories in Nigeria

Physico-chemical properties of palm oil from different Nigerian oil palm local factories were determined at varying temperature. β-carotene contents were determined by spectrophotometric method using spectronic 21D spectrophotometer (Digital) at wavelength of 440 nm. Refractive index was determined by using Abbe refractometer while saponification value, acid value, free-fatty acid contents, ester value, iodine value and peroxide value were determined by titrimetric method. Results showed that palm oil from Ogbomoso had the highest β-carotene contents, while palm oil from Ile-Ife had the least β-carotene content, which was reduced progressively as the experimental temperature increased

Photoelectrochemical degradation of eosin yellowish dye on exfoliated graphite-ZnO nanocomposite electrode

In the quest for harnessing more power from the sun for water treatment by photoelectrochemical degradation, we prepared a novel photoanode of exfoliated graphite (EG)-ZnO nanocomposite. The nanocomposite was characterised by X-ray diffractometry, energy dispersive spectroscopy, Brunauer-Emmett-Teller surface area analyser, thermal gravimetric analyser, and X-ray photoelectron spectroscopy. The EG-ZnO nanocomposite was fabricated into a photoanode and applied for the photoelectrochemical degradation of 0.1 x 10(-4) M eosin yellowish dye in 0.1 M Na2SO4 under visible light irradiation. The degradation was monitored with a visible spectrophotometer. The photoelectrochemical degradation process resulted in enhanced degradation efficiency of ca. 93 % with kinetic rate of 11.0 x 10(-3) min(-1) over photolysis and electrochemical oxidation processes which exhibited lower degradation efficiencies of 35 and 40 % respectively

Synthesis, spectral and thermal studies of pyridyl adducts of Zn(II) and Cd(II) dithiocarbamates, and their use as single source precursors for ZnS and CdS nanoparticles

The synthesis, spectroscopic characterisation, and thermal studies of pyridyl adducts of Zn(II) and Cd(II) complexes of N-ethyl-N-phenyl dithiocarbamate, represented as [ZnL2py] and [CdL2py2], are reported. Single-crystal X-ray structural analysis of the Zn compound showed that it is five-coordinate with four sulphurs from dithiocarbamate and one nitrogen from pyridine in a distorted square pyramidal geometry. The thermogravimetric studies indicate that the zinc and cadmium compounds undergo fast weight loss, and the temperature at maximum rate of decomposition is at 277 °C and 265 °C respectively, to give the metal (Zn or Cd) sulphide residues. These compounds were used as single molecule precursors to produce nanocrystalline MS (M = Zn, Cd) after thermolysis in hexadecylamine. The morphological and optical properties of the resulting MS nanocrystallites were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-Vis absorption and photoluminescence (PL) spectroscopy, and powdered X-ray diffraction (XRD). By varying the growth time, the temporal evolution of the optical properties and morphology of the nanocrystals were investigated.National Research Foundation (NRF), South Africa, and North-West University, Potchefstroom, South Afric