Effects of Pithecellobium jiringa ethanol extract against ethanol-induced gastric mucosal injuries in Sprague-Dawley rats

Current anti-gastric ulcer agents have side effects, despite the progression and expansion of advances in treatment. This study aimed to investigate the gastroprotective mechanisms of Pithecellobium jiringa ethanol extract against ethanol-induced gastric mucosal ulcers in rats. For this purpose, Sprague Dawley rats were randomly divided into five groups: Group 1 (normal control) rats were orally administered with vehicle (carboxymethyl cellulose), Group 2 (ulcer control) rats were also orally administered with vehicle. Group 3 (positive control) rats were orally administered with 20 mg/kg omeprazole, Groups 4 and 5 (experimental groups) received ethanol extract of Pithecellobium jiringa ethanol extract at a concentration of 250 and 500 mg/kg, respectively. Sixty minutes later, vehicle was given orally to the normal control group, and absolute ethanol was given orally to the ulcer control, positive control and experimental groups to generate gastric mucosal injury. The rats were sacrificed an hour later. The effect of oral administration of plant extract on ethanol-induced gastric mucosal injury was studied grossly and histology. The level of lipid peroxidation (malondialdehyde-MDA), superoxide dismutase (SOD) and gastric wall mucus were measured from gastric mucosal homogenate. The ulcer control group exhibited severe gastric mucosal injury, and this finding was also confirmed by histology of gastric mucosa which showed severe damage to the gastric mucosa with edema and leucocyte infiltration of the submucosal layer. Pre-treatment with plant extract significantly reduced the formation of ethanol-induced gastric lesions, and gastric wall mucus was significantly preserved. The study also indicated a significant increase in SOD activity in gastric mucosal homogenate, whereas a significant decrease in MDA was observed. Acute toxicity tests did not show any signs of toxicity and mortality up to 5 g/kg. The ulcer protective effect of this plant may possibly be due to its preservation of gastric wall mucus along with increased SOD activity and reduction of oxidative stress (MDA). The extract is non-toxic, even at relatively high concentrations.     

Bulk-modified modified screen-printing carbon electrodes with both lactate oxidase (LOD) and horseradish peroxide (HRP) for the determination of L-lactate in flow injection analysis mode

A screen-printed carbon electrode modified with both HRP and LOD (SPCE–HRP/LOD) has been developed for the determination of l-lactate concentration in real samples. The resulting SPCE–HRP/LOD was prepared in a one-step procedure, and was then optimised as an amperometric biosensor operating at [0, −100] mV versus Ag/AgCl for l-lactate determination in flow injection mode. A significant improvement in the reproducibility (coefficient variation of about 10%) of the preparation of the biosensors was obtained when graphite powder was modified with LOD in the presence of HRP previously oxidised by periodate ion (IO₄⁻). Optimisation studies were performed by examining the effects of LOD loading, periodation step and rate of the binder on analytical performances of SPCE–HRP/LOD. The sensitivity of the optimised SPCE–HRP/LOD to l-lactate was 0.84 nA L μmol⁻¹ in a detection range between 10 and 180 μMol. The possibility of using the developed biosensor to determine l-lactate concentrations in various dairy products was also evaluated.     

Determination of hexavalent and tetravalent uranium in phosphate ores through hydrochloric acid selective leaching

The tetravalent and hexavalent uranium content of three Egyptian phosphate type ore samples namely; Sebayia, Abu Tartur and Qatrani have been studied through selective leaching by hydrochloric acid at normal, oxidized and reduced conditions at an amount of hydrochloric acid less than the stoichiometric value i.e. before phosphoric acid production. Oxidizing condition is attained by incorporating 2% of manganese dioxide in the leaching cycle, whereas reducing condition is attained by adding 2% iron powder. The achieved results show that the amount of tetravalent uranium varies between 5 and 95%. As soon as the achieved stoichiometric value of hydrochloric acid is sufficient to produce phosphoric acid both tetravalent and hexavalent uranium dissolve by virtue of phosphoric acid complexing power for uranium. The chemical form of uranium in the ore determines the type of solvent needed to recover it.     

Uranium uptake from acidic solutions using synthetic titanium and magnesium based adsorbents

Uranium uptake from acidic solutions is comprised practically in this study into three main steps namely; adsorbent synthesis, uranium uptake procedure, and desorption step. In this respect, two uranium adsorbents were synthesized from mineral processing of ilmenite and talc. Titanium phosphate adsorbent (TP) was deposited from titanium sulfate solution obtained from ilmenite sands processing. On the other hand, magnesium silicate adsorbent (MS) is prepared by sodium metasilicate neutralization of the acidic magnesium bearing waste solution resulted from talc whitening process. Structurally and chemically the two adsorbents were investigated by XRD, IR and SEM-EDX analyses. The studied factors affecting the uranium uptake onto TP and MS adsorbents were uranium concentration (10–1000 ppm), acidic pH range (1–6), contact time, shaking time and solid to liquid ratio. The uranium analysis was determined spectrophotometrically using arsenazo(III) dye where SEM-EDX analysis confirmed the uranium uptake by adsorbents. The optimum conditions obtained were applied to uranium bearing, highly mineralized granite samples (5200 ppm U) and black shale (40 ppm U). The uranium uptake was more than 98% for the mineralized granite samples and more than 97% for shale. The loaded uranium was recycled by using 0.5 and 1M HNO₃ in case of TP and MS with percentage recovery of 96 and 98% respectively.     

Batch process monitoring and its application to polymerization systems

Slight changes in raw material properties or operating conditions during critical periods of operation of batch and semi-batch polymerization reactors may have a strong influence on reaction mechanism and impact final product quality. Online process monitoring, fault detection, fault diagnosis, and product quality prediction in real-time ensure safe reactor operation and warn operators about excursions from normal operation that may lead to deterioration in product properties. Multivariate statistical process monitoring and quality prediction using multiway principal components analysis and multiway partial least squares have been successful in detecting abnormalities in process operation and product quality. When abnormal process operation is detected, fault diagnosis tools are used to determine the source cause of the deviation. Illustrative case studies are presented via simulated polyvinyl acetate polymerization.     

The reaction of active and stabilized phosphonium ylides with α,β-unsaturated carbonyl compounds [1]

The active ketenylidene-(2a) or thioketenylidenetriphenylphosphoranes (2b) react with 2-benzylidene-1,3-indandione (1), 5-benzylidenebarbituric acid (11), and 4-benzylidene-1,2-diphenyl-3,5-pyrazolidinedione (16) to give the corresponding pyranones and thioxopyranones (3a,b, 12a,b) and (17a,b), respectively. On the other hand, compounds 1 and 11 can be converted by reaction with the stabilized alkylidenephosphoranes 4a–e into the phosphoranylidenes 6a–e and 13a–e. Moreover, the oxaphosphinins 8 or 14 and the oxazaphosphinins 10 or 15 were obtained when compounds 1 and 11 were allowed to react with the phosphorane 7 and the iminophosphorane 9, respectively. Some of these new organophosphorus compounds are found to have insecticidal and molluscicidal properties against cotton leafworm Spodoptera littoralis larvae and Biomphalaria alexandrina snails. © 1997 John Wiley, & Sons, Inc.     

Mesogenic 3,6-bis(4-hydroxyphenyl)-1,2,4,5-tetrazine alkanoate esters

A novel series of 3,6-bis(4-hdroxyphenyl)-1,2,4,5-tetrazine alkanoate esters were synthesized and their mesogenic properties were studied using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The impact of changing the tail-core linkage from alkyl or alkoxy to ester is profound. Compared to the alkyl or alkoxy linkages, the ester linkage reduced mesogenic properties. Short-tailed compounds are non mesogenic (4a-4e), while long-tailed compounds (4f-4r) exhibit nematic phases. Unlike the alkyl or alkoxy tail series, none of the 18 presented esters in this series exhibits a smectic phase.     

Sonocatalytic degradation of methylene blue using spindle shaped cerium oxide nanoparticles

Journal of Solid State Electrochemistry - The industrial revolution has raised major concern of environmental pollution, due to excess release of hazardous chemical, dyes, etc. into water bodies....     

Use of Formic Acid as a CO Surrogate for the Reduction of Nitroarenes in the Presence of Dienes: A Two-Step Synthesis of N-Arylpyrroles via 1,2-Oxazines

Formic acid, activated by acetic anhydride and a base, was employed as a CO surrogate to deoxygenate nitroarenes to nitrosoarenes, a reaction catalyzed by a palladium/phenanthroline complex in the homogeneous phase. Nitrosoarenes were trapped by conjugated dienes to give 3,6-dihydro-2H-[1,2]-oxazines. The latter were then transformed into N-arylpyrroles employing CuCl as the catalyst. The reaction was designed to give the best results for pyrroles lacking any substituent in the 2 and 5 positions, which are difficult to produce employing most pyrrole syntheses.     

Dispersing behavior of recycled rubber particles

The hydrophobic nature of recycled rubber particles presently limits their use only in non-aqueous media. Recycled rubber particles were chemically modified by preparation of amphiphilic semi-interpenetrating polymer networks using poly(acrylic acid) as the hydrophilic polymer. The resulting composite particles are water dispersible and suitable for various aqueous media applications.