Perfusion Fixation With Glutaraldehyde and Post-Fixation With Osmium Tetroxide for Electron Microscopy

The conductivity of cerebral cortex drops during perfusion with glutaraldehyde in 5 min to about 60% of the original value, to remain unchanged during the subsequent 10-15 min of perfusion. Circulatory arrest causes a similar drop in the tissue conductivity. Perfusion of asphyxiated tissue with glutaraldehyde does not produce additional major changes in the conductivity. Perfusion of the cortex with an osmium tetroxide solution causes an initial drop in conductivity. However, after about 3 min this trend is reversed and the conductivity increases again to close to the pre-perfusion value. Perfusion of asphyxiated cortex with OsO4 causes a marked increase of the conductivity. So does perfusion with an OsO4 solution of tissue previously treated with glutaraldehyde. One interpretation of these impedance changes is that glutaraldehyde perfusion causes, like asphyxiation, a transport of extracellular material into the intracellular compartment and that during OsO4 perfusion an extracellular space is again created. This possibility is supported by electron micrographs made of this material. Cerebral cortex perfused with glutaraldehyde and post-fixed with OsO4 shows electron-transparent dendritic elements and to a lesser extent pre-synaptic terminals, which seem to be swollen. When the cortex is flooded with a salt solution during glutaraldehyde perfusion the dendrites exhibit ballooning in the surface layer of the cortex, suggesting that the fluid on the cortex participates in the swelling. The tissue elements in the glutaraldehyde-perfused and OsO4 post-fixed cortex are separated by narrow extracellular spaces. The latter may have been produced by the OsO4 perfusion as is suggested by a comparison of micrographs prepared by freeze substitution (which tends to preserve the water distribution) of glutaraldehyde-perfused but not post-fixed cortex with micrographs of cortex treated with OsO4 after the glutaraldehyde perfusion. In accordance with the conductivity changes, the former micrographs showed very little extracellular space, and in many places tight junctions, whereas the latter showed clefts between the tissue elements

Factors influencing branchless banking for microfinance in Sudan: Theoretical perspectives and future directions

In Sudan more than 40% live below the poverty line and getting basic financial service poses a challenge to financial institutions. Most of these unserved populations live in far-flung areas that make it difficult for microfinance institutions to reach them. But the enormous growth of mobile technology industry has created new opportunity to expand financial services to this unserved population. Branchless banking is one of the latest technologies that have been employed in different developing countries to expand financial services to the unbanked poor. Despite the potential benefits and relevance of Branchless banking to Sudan, there are still very few studies on Branchless banking in Sudan. To address this gap in the literature, this study aims to investigate the factors that are essential to the development of branchless banking in Sudan using mobile technology. This is a research-in-progress paper, the critical review of the literature so far revealed that there are essential factors for the success of branchless banking in Sudan e.g. the identification of the industry key players and their roles, the enabling regulatory environment, the infrastructure readiness and Sudanese cultural values. The paper will provide regulators and policy makers in Sudan a way forward to expedite the development of suitable Branchless banking for microfinance in Sudan

Polarographic Study of Some Nitrosonaphthols at d.m.e. in Aqueous Solutions & Water-Ethanol Mixtures of Varying pH

19-2

Inspiratory Conductance does not vary with Height, Weight, Body Mass Index, Age, Sex or Spirometric Volumes in Healthy Adults

Introduction and objective: We previously showed that inspiratory conductance (IC) can be calculated from early inspiratory pressure fall and initial acceleration of the inspiratory air column. To characterize IC further we conducted a study to determine whether its value varies with height, weight, BMI, age, sex and lung volumes. Methods: We measured IC, height, weight, FEV1, FVC and PEFR in 147 healthy volunteers’ age 18-50 years. Results: During tidal breathing at rest the mean (SD) IC was 8.31 (3.15) L s-1 kPa-1. No significant correlation was found between IC and height (r=0.04), weight (r=0.142), BMI (r=0.058), FEV1 (r=0.275), FVC (r=0.019), PEFR (r=0.182) or age (r=0.017) and there was no significant difference between men and women. The same was found for IC measured during slow deep breathing and rapid breathing. Conclusion: IC is independent of age, sex, height, weight, BMI and spirometric lung volumes so there is no imperative to correct for those factors in an individual. Within-subject directional changes in IC within the context of a short clinical timeframe might be the best potential for clinical application

Polarographic Study of Some Nitrosonaphthols at d.m.e. in Aqueous Solutions & Water-Ethanol Mixtures of Varying pH

19-2

Spectrophotometric Studies of Some Nitrosonaphthols

713-71

Changes in Extracellular Space of the Mouse Cerebral Cortex During Hydroxyadipaldehyde Fixation and Osmium Tetroxide Post-Fixation

Perfusion of the cerebral cortex of mice with a 4.5 and 12.5% hydroxyadipaldehyde (HAA) solution in a cacodylate buffer caused a biphasic change in the tissue conductivity. After a latency of a fraction of a minute the cortical conductivity dropped markedly, reaching a minimum in 1.5-2 min. Then the conductivity increased again. Electron micrographs (EMs) of material perfused with HAA for 15-20 min and post-fixed with osmium tetroxide showed electron-transparent swollen structures, some of which could be identified as dendritic. The extracellular space consisted of 100-200 Å slits between the tissue elements and larger spaces in bundles of small profiles (unmyelinated axons). Cortex frozen after 2 min perfusion with HAA and subjected to substitution in acetone containing 2 % OsO4 at -85 °C showed swollen (dendritic) structures and a paucity of extracellular material in accordance with the conductivity drop. Often tight junctions between the tissue elements were present. Tissue frozen after 15-20 min of HAA perfusion when the conductivity had increased again yielded EMs which were characterized by an abundance of extracellular space between the small profiles. The mitochondria in the swollen (dendritic) structures were enormously enlarged. Cortex perfused for 15-20 min with HAA, post-fixed with OsO4 and then freeze substituted produced EMs resembling those of tissue fixed in the same way but not subjected to freeze substitution. The examination of the fixation process by freeze substitution demonstrated a sequence of major changes in the fluid distribution of the tissue which precludes any direct relationship between the spaces in the normal and fixed tissue

Spectral Studies on Some Hydrazones of 6-Formyl-7-hydroxy-5-methoxy-2-methylchromone

962-96

Solar Disinfection of Drinking Water with Polyethylene Terephthalate Bottles Coated with Nano-Titanium Dioxide

Water disinfection processes in the presence of titanium dioxide as a photo-catalyst material provide an interesting route to destroy contaminants, being operational in the UV-A domain with a potential use of solar radiation. In recent years, advanced oxidation processes (AOP) have been developed to meet the increasing need of an effective wastewater treatment. AOP generates powerful oxidizing agent hydroxyl radicals which completely destroy the pollutants in waste water. Solar disinfection of drinking water with polyethylene terephthalate (PET) bottles coated with photo-catalyst TiO2 has been shown to be very effective. The study is based on comparison between three systems for treating contaminated water samples using PET bottles. First system was a PET untreated bottle, the second system was a PET bottle coated with black paint on its outer surface. Finally the third system was a PET bottle coated also with a black coat on its outer surface and its inner part was treated with citric acid solution to enable np-TiO2 to cover the surface later on, then 0.2 g of np-TiO2 powder (of particle size <25 nm, Sigma-Aldrich) was added. The total bacterial accounts were determined to monitor the effect in the three systems. The experimental results have shown that disinfecting water with merely UV was less effective than combining the bottle with heat effect, and adding TiO2 film was further more benefited. This work can be applied in rural areas, with no technical support or need for expensive/dangerous chemicals for drinking safe water even if is stored for two days

Validated Chromatographic Methods for the Simultaneous Determination of Sodium Cromoglycate and Oxymetazoline Hydrochloride in a Combined Dosage Form

Two chromatographic methods were developed and validated for the simultaneous determination of Sodium Cromoglycate (SCG) and Oxymetazoline Hydrochloride (OXMT). SCG and OXMT are administered in combination for effective treatment of nasal congestion and allergy. The first chromatographic method was based on usingaluminum TLC plates pre-coated with silica gel GF254 as the stationary phase and chloroform: methanol: toluene: triethylamine (5: 2: 4:1, by volume) as the mobile phase followed by densitometric measurement of the separated bands at 235 nm. The second method is a high performance liquid chromatographic method for separation and determination of SCG and OXMT using reversed phase C18 column with isocratic elution. The mobile phase composed of acetonitrile: methanol (2: 1, v/v) at flow rate of 1.0 mL/ min. Quantitation was achieved with UV detection at 220 nm. The validity of the proposed methods was assessed using the standard addition technique. The obtained results were statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at p = 0.05