Effective photodegradation of methomyl pesticide in concentrated solutions by novel enhancement of the photocatalytic activity of TiO2 using CdSO4 nanoparticles.

Annihilation of electrons-holes recombination process is the main remedy to enhance the photocatalytic activity of the semiconductors photocatalysts. Doping of this class of photocatalysts by foreign nanoparticles is usually utilized to create high Schottky barrier that facilitates electron capture. In the literature, because nonpolar nanoparticles (usually pristine metals, e.g., Ag, Pt, Au, etc.) were utilized in the doping process, the corresponding improvement was relatively low. In this study, CdSO4-doped TiO2 nanoparticles are introduced as a powerful and reusable photocatalyst for the photocatalytic degradation of methomyl pesticide in concentrated aqueous solutions. The utilized CdSO4 nanoparticles form polar grains in the TiO2 matrix due to the electrons leaving characteristic of the sulfate anion. The introduced nanoparticles could successfully eliminate the harmful pesticide under the sunlight radiation within a very short time (less than 1 h), with a removal capacity reaching 1,000 mg pesticide per gram of the introduced photocatalyst. Moreover, increase in the initial concentration of the methomyl did not affect the photocatalytic performance; typically 300, 500, 1,000, and 2,000 mg/l solutions were completely treated within 30, 30, 40, and 60 min, respectively, using 100 mg catalyst. Interestingly, the photocatalytic efficiency was not affected upon multiple use of the photocatalyst. Moreover, negative activation energy was obtained which reveals super activity of the introduced photocatalyst. The distinct photocatalytic activity indicates the complete annihilation of the electrons-holes recombination process and abundant existence of electrons on the catalyst surfaces due to strong electrons capturing the operation of the utilized polar CdSO4 nanoparticles. The introduced photocatalyst has been prepared using the sol-gel technique. Overall, the simplicity of the synthesizing procedure and the obtained featured photocatalytic activity strongly recommend the introduced nanoparticles to treat the methomyl-containing polluted water.

Synthesis, spectroscopic, thermal and biological activity studies on triazine metal complexes.

The coordination behaviour of the triazine ligand with NNO donation sites, derived from 3-benzyl-7-hydrazinyl-4H-[1,3,4]thiadiazolo[2,3c][1,2,4]triazin-4-one (HL), towards some metal ions namely Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) are reported. The metal complexes are characterized based on elemental analyses, IR, (1)H NMR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TG, DTG and DTA). The ionization constants of the organic ligand under investigation as well as the stability constants of its metal chelates are calculated spectrophotometrically at 25°C. The chelates are found to have octahedral geometrical structures. The ligand (HL) and its binary chelates are subjected to thermal analyses (TG, DTG and DTA) and the different activation thermodynamic parameters are calculated from their corresponding DTG curves to throw more light on the nature of changes accompanying the thermal decomposition process of these compounds. The synthesized ligand and its metal complexes were found to have biological activity against the desert locust Schistocerca gregaria (Forsk.) (Orthoptera - Acrididae) and its adult longevities.

Biological potential study of metal complexes of sulphonylurea glibenclamide on the house fly, Musca domestica (Diptera-Muscidae): preparation, spectroscopic and thermal characterization.

The ligatation behaviour of sulphonylurea glibenclamide drug is studied in order to give an idea about its potentiality towards some transition metals in vitro systems. Metal complexes of glibenclamide (GCA; H(3)L) drug are prepared and characterized based on elemental analyses, IR, diffused reflectance, magnetic moment, molar conductance and thermal analysis (TG and DTG) techniques. From the elemental analyses data, the complexes are proposed to have the general formulae [M(H(3)L)Cl(n)(H(2)O)(m)].yH(2)O (where M=Cr(III) (n=3, m=1, y=3); Mn(II) (n=2, m=0, y=1); Fe(III) (n=3, m=1, y=0), Co(II) (n=2, m=2, y=0); Ni(II) (n=2, m=2, y=3); Cu(II) (n=2, m=2, y=2) and Zn(II) (n=2, m=0, y=0). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that GCA is coordinated to the metal ions in a neutral bidentate manner with OO donor sites of the amide-O and sulphone-O. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral except Mn(II) and Zn(II) complexes which have tetrahedral structure. The thermal behaviour of these chelates is studied using thermogravimetric analysis (TG and DTG) technique. The activation thermodynamic parameters are calculated using Coats-Redfern method. The GCA drug, in comparison to its metal complexes also is screened for its biological activity against house fly, Musca domestica (Diptera-Muscidae). Dose of 5 microg/insect of GCA is topically applied against 3 days old larval instar of M. domestica. Survival of pupal and adult stages has been affected by the complexes of GCA more than larval instars. Morphogenic abnormalities of larvae, pupae and adults are studied. On the other hand pupation and adult emergence program is deteriorated by the effect of different chemicals.

Adsorption of iron and manganese using low cost materials as adsorbents.

Removal of toxic metals (iron and manganese) ions from aqueous solution by adsorption was studied. Batch tests were used to study the removal of each metal either as a single component or both metals as multicomponent. The adsorbents used are low cost materials namely; palm fruit bunch and maize cobs. The adsorption isotherms proved the favor ability of the adsorbent used. Removal of iron ion by adsorption on palm fruit bunch and maize cobs was in the range of 80-57%, and for magnesium ion in the range of 79-50% for initial concentration ranged between 1 and 10 ppm. In case of mixture of both metals, removal of iron from the mixture was in the range 79-54% and for magnesium was in range of 76-54%.

Removal of chromium from tannery effluents by adsorption.

Tannery effluent is characterized not only by heavy loads but also with toxic heavy metals especially chromium ions. Chromium is considered an important source of contamination due to large volume of exhaust liquid discharged and solid sludge produced. Details on adsorption studies were carried out using synthetic chromium salts (chromium chloride) as adsorbate, and cement kiln dust (a waste from white cement industry) as adsorbent. Equilibrium isotherms have been determined for the adsorption of chromium ions on cement kiln dust. Kinetic study provided that the adsorption process is diffusion controlled. The experimental results have been fitted using Freundlich, Langmuir, and Redlich Peterson isotherms. The maximum adsorption capacity of cement kiln dust was found to be 33 mg/g. Industrial tannery effluent (22-mg/L chromium and COD 952 mg/L) was also treated by cement dust. The treated effluent (using 20 g cement dust per 1 L) contains only 0.6 mg/L chromium and COD 200 mg/L.

Effectiveness of IGRS (CGA-184699) and (CGA-259205) on the respiratory metabolism of the red palm weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae).

Prepupae of Rhynchophorus ferrugineus were topically applied with one of three dose-levels (1.00, 0.10 or 0.01 microgram/insect) of lufenuron (CGA-184699) or diofenolan (CGA-259205). The daily O2 consumption and CO2-output were determined and the respiratory quotient (RQ) was calculated. Lufenuron prohibited the pupae to consume O2, regardless of their age. Considering the CO2 release, this IGR exerted an inhibitory action on pupae increasingly correlated with the increasing dose-level. Volumes of consumed O2 reversely correlated with the dose value of diofenolan. Also, CO2 output was suffered an inhibitory effect of diofenolan which was consecutively related to the dose value. An U-shaped pattern of daily respiration was not, unfortunately, attained, irrespective of the IGR or its dose. In addition, RQ mean values were less than unity but exceeded 0.7.

Assessment of two natural marine toxins (Microcystis aeruginosa and Parasicyonis actinostoloides) for the control of some medical and agriculture insects with reference to the action on mice.

The present work describes the insecticidal potentiality from Microcystis aeruginosa (cyanobacteria) and Parasicyonis actinostoloides (Sea anemone) water extracts against 3rd larval instar of medical insects (Musca domestica and Culex pipiens) and 4th larval instar of agriculture insects (Spodoptera littoralis and Agrotis ipsilon. The LD50s of M. aeruginosa extract were 1.94, 2.33, 7.59 and 9.10 mg/ml. for M. domestica, C. pipiens, S. littoralis and A. ipsilon). respectively. While LD50s of P. actinostoloides extract were 19.28, 24.7, 27.3 and (29.4) mg/ml. for M. domestica, C. pipiens, S. littoralis, and A. ipsilon respectively. The aqueous extracts of M. aeruginosa and P. actinostoloides had no acute or chronic marked effect on mice as serum acetyl cholinesterase and gave more or less nearly the same level of AchE activity at the end of decapitation periods.

Evaluation of four pediculicides against the head lice Pediculus h. capitis.

Four pediculicides were tested against head lice in-vitro. The LT50 for Licid ranged between 10.75 (at conc. 50%) to 25.08 (at conc. 1%). All lice died with conc. 100% within 5 minutes. With Malathion, the LT50 ranged between 4.23 to 9.3 at conc. 50% to 1% respectively. All lice died with conc. 57% within 3 minutes. With Benzanil, the LT50 ranged between 20.85 to 44.34 at conc. 50% to 1% respectively. All lice died at conc. 2.5% within 10 minutes. With Para plus, the LT50 ranged between 18.46 to 29.5 at conc. 100% to 50% respectively. All lice died with conc. 100% within 30 minutes. So, the least time needed to kill all lice was given with Malathion (3 minutes). The least dose of pediculicide needed to kill all lice was those of Benzanil (1% = 0.025) and Malathion (1% = 0.57). The whole results were discussed regarding the advantages and disadvantages of these pediculicides.

Two contagious ectoparasites in an orphanage children in Nasr City, Cairo.

Lice and scabies are the main ectoparasites transmitted by contagious, particularly among children living in crowded areas. Examination of an orphanage children (both sex, 2-6 years old), showed infestation with head louse (64.1%), body louse (53.8%) and scabies (26.9%). The results were discussed on the light of the work done before.

Efficacy of BaySir-8514 and precocene II against the grey flesh fly Parasarcophaga dux (Thomson) (Diptera: Sarcophagidae).

Five doses (1, 0.5, 0.25, 0.125 and 0.0625) of the chitin inhibitor BaySir-8514, and anti-juvenoid precocene II were topically applied to the third larval instar of the grey flesh fly Parasarcophaga dux. Toxicity of both compounds were recorded against different developmental stages at the different dose levels. The lowest dose (0.0625) of both compounds caused a low toxicity percent (0.1). On the other hand, the highest dose (1mg) increased the larval, pupal and adult malformations after larval treatment by both compounds. Highest percentage of larval deformations was obtained by the maximal dose-level (1mg), which in turn did not lead to the highest percentage of adult deformations. Shortening of larval-pupal durations and adult longevities were observed. Sterilizing action of precocene II on P. dux could be remarkably detected by the effect of higher doses (0.5 and 1%) on the 3rd larval instar because no larvae were deposited by the emerging adult females. Doses of 0.125 and 0.0625 mg inhibited the female natality.

The insecticidal activity of Cyanobacteria against four insects, two of medical importance and two agricultural pests with reference to the action on albino mice.

Acute lethal toxicity of Cyanobacteria (blue-green algae) was investigated against 3rd larval stages of Musca domestica, and Culex pipiens, and 4th larval stages of Spodoptera littoralis and Agrotis ipsilon. The LD50s were 1.94, 2.33, 7.59 and 9.10 microg for M. domestica, C. pipiens, S. littoralis and A. ipsilon respectively. The slope functions were 4,045 +/- 0.332 (M. domestica), 4.122 +/- 0.336 (C. pipiens), 4.15 +/- 0.35 (S. littoralis) and 3.72 +/- 0.34 (A. ipsilon). These LD50s markedly affected the larval, pupal and adult time of durations as well as suppressed the oviposition of the survivor adults. The LD50 didn't show any marked effect as serum acetyl cholinesterase and gave nearly the same level of AchE activity. No doubt, Cyanobacteria are safe and promising agent for insect control.

The prevalence of localized juvenile periodontitis in Saudi subjects.

The purpose of this study was to determine the prevalence and sex ratio of localized juvenile periodontitis (LJP) cases in a selected Saudi population, to compare these values with different societies, and to correlate the sex ratio with the presence of Actinobacillus actinomycetemcomitans in the afflicted sites. In a retrospective study over a 3-year period 23 cases of LJP were diagnosed from a group of 5,480 subjects with different forms of periodontal disease. The overall prevalence was 0.42%. The female to male ratio was 1.88:1. The difference in the sex ratio was statistically significant (X = 5.490, P < .05). No statistically significant difference in the sex ratio association regarding the sites afflicted by Actinobacillus actinomycetemcomitans was found.