Synthesis and Characterization of Starch-Graft-Acrylamide Hydrogel for Oral Drug Delivery

In this research, starch was extracted from fresh sweet potato and was used to prepare starch-g-acrylamide hydrogel using free radical polymerization method with potassium per sulphate and N’N-Methylene bisacrylamide as initiator and cross-linker, respectively. The swelling capacity and pH sensitivity of the synthesized hydrogel were investigated in solutions of various pH (1-12). The drug loading and release experiment was also carried out using promethazine (PMZ) as the model drug at 25oC and 37oC, respectively while the release study was carried out in an enzyme-free simulated gastric intestinal fluid (SGF) and simulated intestinal fluid (SIF). The result showed a 905% swelling at pH 11, suggesting increased swelling capacity at higher pH values. Drug loading result indicated 99% of the drug was entrapped by the hydrogel as confirmed by UV-visible spectrophotometry. SIF and SGF Simulation indicated a 24% and 9% drug release for the first ten hours. At the end of 48 hours the release was 96% and 89%, respectively indicating the hydrogel released more promethazine in SIF than in SGF. The results obtained in this work suggest that starch-graft-acrylamide hydrogel is a potential vehicle for oral drug delivery. Keywords: Starch, Acrylamide, Hydrogel, Drug delivery

Extended γ‐ray emission in solar flares

During the solar flare events on 11 and 15 June 1991, COMPTEL measured extended emission in the neutron capture line for about 5 hours after the impulsive phase. The time profiles can be described by a double exponential decay with decay constants on the order of 10 min for the fast and 200 min for the slow component. Within the statistical uncertainty both flares show the same long‐term behaviour. The spectrum during the extended phase is significantly harder than during the impulsive phase and pions are not produced in significant numbers before the beginning of the extended emission. Our results with the measurements of others allow us to rule out long‐term trapping of particles in non‐turbulent loops to explain the extended emission of these two flares and our data favour models based on continued acceleration

Prevalence of extended spectrum β-lactamases (esbls) among enterobacteriaceae in murtala mohammed specialist hospital, Kano, Nigeria

Confirmed variants of enterobacteriaceae isolated from 143 patients that attended Murtala Mohammed Specialist Hospital Kano, were screened for extended spectrum β-lactamases (ESBLs) production using Clinical Laboratory Standards Institute (CLSI) breakpoint. Suspected ESBLs producers were subjected to confirmation using Disc Replacement Method (DRM). Standard discs of augmentin {AMC 30μg (Oxoid, England)}, ceftriaxone {AUF 30μg (Oxoid, England)} and ceftazidime {RP 30μg (Oxoid, England)} were used in the screening. Of the 143 isolates screened, 114 (79.72%) were Gram negative isolates belonging to the family enterobacteriaceae. Among the enterobacteriaceae isolates screened, the results of CLSI breakpoint test showed that 76 (66.7%) were ESBLs producers viz: Citrobacter spp. (3), Enterobacter spp. (2), E. coli (28), Klebsiella spp. (18), Morganella morganii (7), Proteus spp. (13), Salmonella spp. (1), Serratia spp. (1), Shigella spp. (2) and Yersinia spp (1). On subjecting the CLSI positive isolates to DRM, only 47 (41.2%) were confirmed ESBLs producers. These include; Citrobacter spp. (1), E. coli (20), Klebsiella spp. (12), Morganella morganii (4), Proteus spp. (8), Salmonella spp. (1) and Shigella spp. (1). ESBLs occur at an alarming rate among enterobacteriaceae isolates in Kano which calls for government intervention in the healthcare setting

Classes of Ordinary Differential Equations Obtained for the Probability Functions of Harris Extended Exponential Distribution

In this paper, the differential calculus was used to obtain some classes of ordinary differential equations (ODE) for the probability density function, quantile function, survival function, inverse survival function and hazard function of the Harris extended exponential distribution. The case of reversed hazard function was excluded because of its complexity. The stated necessary conditions required for the existence of the ODEs are consistent with the various parameters that defined the distribution. Solutions of these ODEs by using numerous available methods are new ways of understanding the nature of the probability functions that characterize the distribution. The method can be extended to other probability distributions, functions and can serve an alternative to estimation and approximation

INFLUENCE OF A LOW TEMPERATURE AGEING ON THE PROPERTIES OF AL-6.5%SI-0.35%MG ALLOY

The effect of a low temperature ageing treatment on the hardness, tensile and corrosion characteristics of sand cast Al-6.5%Si-0.35%Mg alloy was studied. The temper conditions are low temperature ageing at 90oC, 95oC, 100oCand 105oC respectively followed by ageing to 180oC for 2 hrs. This was compared with the control sample which was aged directly to 180oC for 2hrs. The hardness of the Al-6.5%Si-0.35%Mg alloy was measured using the Rockwell-HRB scale hardness tester, while the tensile characteristic was evaluated using a graphical tensometer. The corrosion resistance of the alloy was evaluated using weight loss analysis in simulated sea water environment. An increase in the hardness characteristic was observed in the low temperature ageing at 90oC (7.8 HRB) as compared with (6.0 HRB) that was obtained for the control. From the tensile results obtained, the extension value for the control samples was (1.4 mm) while the sample with a low temperature ageing of 105oC gave the highest extension of (2.26 mm). Remarkable decrease in corrosion rate was observed at 95oC (2.3373 mm/yr x10-7) as compared with the control of (5.2049 mm/yr x10-7). From the Optical Microscope (OPM) and Scanning electron microscope (SEM) results, it was observed that the microstructures were refined for low temperature ageing when compared with the control samples. From these results, it can be deduced that the low temperature ageing treatment had an appreciable influence on the properties of this alloy. http://dx.doi.org/10.4314/njt.v35i3.1

X- and gamma-ray observations of the 15 November 1991 Solar Flare

This work expands the current understanding of the 15 November 1991 Solar Flare. The flare was a well observed event in radio to gamma-rays and is the first flare to be extensively studied with the benefit of detailed soft and hard X-ray images. In this work, we add data from all four instruments on the Compton Gamma Ray Observatory. Using these data we determined that the accelerated electron spectrum above 170 keV is best fit with a power law with a spectral index of −4.6, while the accelerated proton spectrum above 0.6 MeV is fit with a power law of spectral index −4.5. From this we computed lower limits for the energy content of these particles of∼1023 ergs (electrons) and ∼1027 ergs (ions above 0.6 MeV). These particles do not have enough energy to produce the white-light emission observed from this event. We computed a time constant of 26+20−15 s for the 2.223 MeV neutron capture line, which is consistent at the 2σ level with the lowest values of ∼70 s found for other flares. The mechanism for this short capture time may be better understood after analyses of high energy EGRET data that show potential evidence for pion emission near ∼100 MeV

Investigating the Effect of Varying Tubing Air Concentration during the Descaling of Petroleum Production Tubing using Multiple High-Pressure Nozzles

Despite the continued research effort on erosion behaviour of multiple flat fan nozzles in removing different types of scale deposits from petroleum production tubing, effect of chamber air concentration and nozzles configuration is yet to be given detail consideration. This study, therefore, considers the utilization of multiple high-pressure sprays at different chamber air concentration to enhance the rate of scale removal from petroleum production tubing. Additionally, options of altering chamber air/water ratio and header configurations for more effective scale removal were explored. So also, the relationship of nozzle header arrangement towards the removal of paraffin of different stages of deposition in petroleum production tubing have been studied. Consequently, theselection of chamber air concentration and header configuration (nozzles arrangement) for effective scale removal was found to be governed by the shape and type of the scale deposit. More so, the descaling capacity increases with decrease in number of nozzlesdue to pressure drop effect irrespective of the type or shape of the scale deposit. This novel descaling experiment of utilising 10 MPa injection pressure from 25 mm jetting position averagely removes hollow paraffin deposits that ranges from 44 to 280 g and 34 to 89g of solid shaped paraffin as a result of altering nozzles configuration. Correspondingly, an average removal difference ranging from 48 to 270 g of hollow shaped and 35 to 218 g of solid shaped paraffin depositwas recorded as a result of compressing the chamber pressure by 0.2 MPa and subsequently suctioning it by -0.008 MPa respectively

On-Orbit Results of Photoelectron Current Measurement System in Low Earth Orbit on HORYU-IV Satellite

On-orbit photoelectron current experiment is one of the missions carried out with the less resource available from a HORYU-IV satellite, for measuring the current from metallic and insulator surfaces from air mass zero (AMO) spectrum. This is with the view to determined photoelectron potential of materials widely used in spacecraft in space. HORYU-IV also known as Arc Event Generator and Investigator satellite (AEGIS) is among HORYU satellite series of Kyushu Institute of Technology, which was launched on February 17, 2016 as a piggy-back on-board H-IIA rocket. The measurement system consists of current-voltage amplifier circuits for Au, Kapton and Black Kapton samples with varying gains and other discrete components. We present the analysis of the telemetry data obtained after the launch; validate the effectiveness of the design and verification processes. The results show that the current measured from Black kapton sample surface had 1.80 nA and 2.70 nA, corresponds to 69.1ᵒ and 75.1ᵒ minimum and maximum elevation angles respectively. This paper described the on-orbit result of PEC and its verification through ground tests

COMPTEL’s solar flare catalog

COMPTEL, the imaging gamma‐ray telescope, capable of detecting gamma rays in the range of 0.1–30 MeV, is one of four instruments aboard NASA’s Compton Gamma‐Ray Observatory. The Comptel burst detectors (single Defector Mode) have a field of view of ∼2.5 π sr. These detectors of COMPTEL permit measurements of energy spectra and time histories of solar flare gamma‐ray emission. A search through the Single Detector Mode’s data is being conducted. We summarize the preliminary results of this search