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Background: Ovarian cysts are more common in adolescents than has been assumed. Large ovarian cysts, however, are rare. Conventionally, large ovarian cysts have been managed by laparotomy. Laparosc...

Here, for the first time, europium was incorporated into the open-structure three-dimensional mesoporous siliceous material. Samples with different loadings of europium were synthesized through one-step hydrothermal treatment based on sol-gel technique. The prepared samples were characterized by different characterization techniques and the results showed the formation of isolated trivalent europium ions in silica matric at low loading samples. However, at high loading samples, nanoparticles of europium III oxide, with an average size of 5–10 nm size, were detected inside the pores of mesoporous silica matrix. The photoluminescence property of the prepared samples was investigated at two different excitation wavelengths of 393 nm and 466 nm. The maximum photoluminescence emission intensity peaks was observed at approximately 614 nm at the two-excitation wavelength. The intensity of emission peak for the 614 nm was also found to be enhanced with increasing the loading of europium ions, this signify that europium acts as a good luminescent activator for red phosphor.

Two methods were used to prepare Mn3O4 followed by deposition of Pd nanoparticles with 2 and 4 wt.%. The textural and structural properties were characterized by several methods. The XRD results showed the participation of MnO2 phase with small amount with tetragonal Mn3O4 due to hydrothermal treatment at 150 °C. Moreover, no changes in the textural properties of Mn3O4 due to the difference in preparation method or Pd nanoparticles deposition. TEM images showed different morphologies such as cubic, spheroid and plate-shaped structures. The XPS study confirmed the distribution of both Pd° and Pd2+ species on the Mn3O4 surface. The reducibility of pure Mn3O4 was greatly enhanced and shifted to lower temperatures after incorporation of Pd nanoparticles. The presence of Pd2+ may facilitate the providing of reactive lattice oxygen for CO oxidation by the support. The performance of the catalysts towards CO oxidation was much more enhanced as the Pd content increased to 4 wt. %. The results showed good stability and durability during the CO oxidation.

In this work, Pd nanoparticles was precipitated over iron oxide that prepared through two basic approaches to look for better dispersion of Pd nanoparticles and robust catalyst for carbon monoxide oxidation. The first involves direct precipitation of iron oxide using sodium hydroxide, and the second involves hydrothermal treatment after precipitation. The catalysts were characterized by many techniques such as, FTIR, XRD, N2 adsorption-desorption, H2-TPR and TEM images. The catalytic activity of the prepared catalysts was tested in CO oxidation reaction. The XRD showed that, α-FeOOH crystalline structure is formed. While, TEM images showed that, α-FeOOH has nanorods structure with different dimensions. The TPR experiment indicated that the reducibility of Pd/FeOOH catalyst was much more enhanced. The results also demonstrate that, as compared with the direct precipitation approach, the hydrothermal treatment after precipitation approach of iron oxide enable better dispersion of Pd nanoparticles as well as hinder the growth of large Pd crystallites which are important to produce outstanding catalysts for carbon monoxide oxidation.

The kinetics of chromic acid oxidation of l -tryptophan in H 2 SO 4 medium at a constant ionic strength of 0.6 mol dm −3 and at 25 °C have been investigated spectrophotometrically. The reaction exhibits a 3:2 stoichiometry (tryptophan:chromic acid). The reaction shows a first order dependence on [chromic acid], a fractional-first order dependence on [tryptophan] and fractional-second order dependence on [acid]. Increasing ionic strength and dielectric constant had no significant effect on the oxidation rate. The final oxidation products of tryptophan were identified as the corresponding aldehyde (indole-3-acetaldehyde), ammonium ion and carbon dioxide. A spectral evidence for the formation of chromium(III) product was obtained. The experimental results suggest formation of an intermediate complex between the protonated tryptophan and chromic acid which decomposes in the rate-determining step to yield the products. The mechanism of such reaction has been proposed. The thermodynamic parameters with respect to the first step of the suggested mechanism were evaluated and discussed.

In the current article, two different functionalities were employed to enhance the photocatalytic performance of the two famous semiconductors; ZnO and TiO2, under UV light illumination. Eu3+ incorporated TUD-1 mesoporous material (Si/Eu ratio of 10) was wet deposited with ZnO and TiO2 with a mass ratio of 1 Eu-TUD-1: 1 ZnO or TiO2. The prepared composites were characterized by means of XRD, DR UV-Vis, Raman spectroscopy, SEM, EDX and HR-TEM. Characterization data confirmed the presence of Eu2O3 nanoparticles embedded in amorphous silica matrix that support the nanoparticles of commercial ZnO or TiO2. The photocatalytic performance of the prepared materials was examined in the decolourization reaction of methyl green (MG) dye under black light illumination with a wavelength centered at 367 nm and at ambient temperature. The activity of the prepared materials was almost 3.4-3.6 times higher than neat ZnO or TiO2 and almost 1.2-1.3 times higher than same composites without silica, under the same condition. The prepared composites were recycled successfully for four consecutive reaction without significant loss in the case of Eu-TUD-1/TiO2 composite and 18-20% of loss activity in the case of Eu-TUD-1/ZnO composite. Hence, the results suggest the application of prepared material as photocatalyst under UV illumination with strong adsorption affinity.

Objective: Burnout is a state of physical and emotional exhaustion and a sense of low personal accomplishment. Our aim was to study the prevalence of burnout among all residents of Oman Medical Specialty Board (OMSB), to increase awareness of burnout among trainers and trainees not only within Oman but also in other countries with similar residency programs. This would help residency directors to increase the performance of their residents. Methods: This is a cross-sectional study with residents of OMSB involved in 17 training programs from April 2018 to April 2019. The residents were invited to answer a validated burnout questionnaire (Maslach Burnout Inventory). Only exclusion criteria were programs with at least three residents. Results: A total of 343 of 555 residents (61.8% of the total OMSB residents) participated in the study. The response rate was 100% of those who got the survey. The overall burnout rate was 16.6%. From postgraduate years (PGY) 1–5, there was a sudden spike of burnout at PGY 2 and PGY 5 at 17.6% and 25%, respectively. Emergency residents had the highest incidence of burnout at 46.2%. Burnouts among surgical, medical, and diagnostic specialties were 13.9%, 19.0%, and 12.8%, respectively. Chi-squared test showed no significant association between burnout and marital status, gender, or number of children at 0.18, 0.88, and 0.55, respectively. The percentage of residents who reported emotional exhaustion was 61.2%, while the highest percentage of depersonalization was 42.6%. Conclusion: Emergency medicine program burnout is alarming. PGY 2 and 5 show higher burnout. The overall burnout in OMSB is low.

The reaction kinetics for the oxidation of l-histidine by permanganate ions have been investigated spectrophotometrically in sulfuric acid medium at constant ionic strength and temperature. The order with respect to permanganate ions was found to be unity and second in acid concentration, whereas a fractional order is observed with respect to histidine. The reaction was observed to proceed through formation of a 1:1 intermediate complex between oxidant and substrate. The effect of the acid concentration suggests that the reaction is acid catalyzed. Increasing the ionic strength has no significant effect on the rate. The influence of temperature on the rate of reaction was studied. The presence of metal ion catalysts was found to accelerate the oxidation rate, and the order of effectiveness of the ions was Cu2+ > Ni2+ > Zn2+. The final oxidation products were identified as aldehyde (2-imidazole acetaldehyde), ammonium ion, manganese(II), and carbon dioxide. Based on the kinetic results, a plausible reaction mechanism is proposed. The activation parameters were determined and discussed with respect to a slow reaction step.

Kinetic investigations on the oxidation of l-asparagine (Asn) by alkaline permanganate have been carried out spectrophotometrically at a constant ionic strength and temperature. The reaction is first order with respect to [MnO4 −] and less than unit order with respect to both [Asn] and [alkali]. The influence of pH indicated that the oxidation is base catalyzed. The reaction rate was found to increase with increasing ionic strength and temperature. The addition of alkali metal ion catalysts accelerates the oxidation rate. The proposed reaction mechanism involves the formation of a 1:1 intermediate complex between l-asparagine and an alkali-permanganate species in a pre-equilibrium step, which was confirmed by both spectral and kinetic evidence. The complex decomposes slowly in a rate determining step, resulting in the formation of a free radical. The latter reacts again with another alkali-permanganate species in a subsequent fast step to yield the final reaction products which were identified as aldehyde (α-formyl acetamide), ammonia, manganate(VI) and carbon dioxide. The appropriate rate laws are deduced. The reaction constants involved in the mechanism were evaluated. The activation and thermodynamic parameters were determined and discussed.

River runoff and atmospheric fallout (dust and air particulate matter) are major input sources of natural and anthropogenic terrestrial organic and inorganic components to the Arabian seas. In this study, we report on the various lipid tracer compounds that might be transported to the Arabian Gulf by rivers, dust, and air particulate matter. These are based on geochemical analysis of sediment, dust, and particulate samples collected from Iraq, Kuwait, and Saudi Arabia. The samples were extracted with a dichloromethane/methanol mixture and analyzed by gas chromatography-mass spectrometry. The extractable organic compounds (lipids) in the samples include n-alkanes, n-alkanoic acids, n-alkanols, methyl n-alkanoates, steroids, triterpenoids, carbohydrates, and petroleum hydrocarbons. The steroids and triterpenoids were major components in river and wetland samples. The major sources of these lipids were from natural vegetation, microbial (plankton and bacteria) residues in the sediments, sand, and soils, with some contribution from anthropogenic sources. Accordingly, these sources could be major inputs to the Arabian seas besides the autochthonous marine products. Future studies of the organic and inorganic biogeochemistry on river, dust, and coastal areas are needed to characterize the various regional sources, transformation, and diagenetic processes of the organic matter en route to the marine environment.

A polyphasic taxonomic study of a halotolerant micro-organism, isolated from Kuwait salt marsh soil, revealed that this strain represents a novel Nocardiopsis species. The strain produced substrate and aerial mycelium, grew at 28-35 degrees C in salt concentrations of 0-15% and was slightly keratinolytic. Results of the 165 rDNA sequence comparison revealed that strain F100T clustered with strains of the genus Nocardiopsis. This is consistent with other data such as: (i) growth characteristics, i.e. the formation of a white to yellow aerial mycelium and the typical zig-zag form of hyphae, which fragment when ageing; (ii) the presence of DL-diaminopimelic acid and glucose plus ribose in whole-cell hydrolysates; (iii) the presence of phosphatidyl choline, phosphatidyl inositol, phosphatidyl glycerol, phosphatidyl methylethanolamine and diphosphatidyl glycerol in polar lipid extracts; (iv) the presence of menaquinones MK-10(H(0-6)) and MK-11(H(0-6)) in the non-polar fraction; (v) the presence of iso/anteiso-branched plus 10-methyl-branched fatty acids, showing the diagnostic combination for Nocardiopsis spp. of 14-methyl-hexadecanoic acid (18%), oleic acid (9%) and tuberculostearic acid (2%); and (v) the absence of mycolic acids. Analysis of 16S rDNA revealed that strain F100T represents a distinct taxon within Nocardiopsis. Based upon phenotypic differences to other members of the genus, a novel species, Nocardiopsis halotolerans sp. nov., is proposed. The type strain of the species is F100T (= DSM 44410T = NRRL B-24124T).

An actinomycete, strain 8T, was isolated from marsh soil in Kuwait. The strain was aerobic, gram-positive, halophilic and produced light blue to greyish aerial mycelium. The warty spores were sessile, occurring singly or in pairs on aerial mycelium. The mycelium was stable and did not fragment during ageing. Chemotaxonomic markers of the isolate were consistent with its classification as Saccharomonospora. The strain possessed meso-diaminopimelic acid as the diagnostic amino acid in the peptidoglycan. The diagnostic sugars were arabinose and galactose; polar lipids were phosphatidyl inositol, phosphatidyl ethanolamine, hydroxy-phosphatidyl ethanolamine, lyso-phosphatidyl ethanolamine and diphosphatidyl glycerol; the principal menaquinone was MK-9(H4); and the iso/anteiso-branched fatty acid pattern was combined with 10-methyl-branched and 2-hydroxy-branched fatty acids. Saccharomonospora cyanea DSM 44106T was the closest phylogenetic neighbour of strain 8T, showing 96.8% 16S rDNA sequence similarity. These data, together with distinct physiological traits, led to the conclusion that the novel isolate represents a new species within the genus Saccharomonospora for which the name Saccharomonospora halophila sp. nov. is proposed. The type strain is strain 8T (= DSM 44411T =NRRL B-24125T).

The effects of alloying Pd and Cu on the infrared spectra of adsorbed CO are firstly, enhancement of linearly adsorbed CO on Pd at the expense of bridged CO on Pd due to dilution of exposed ensembles of Pd by Cu, secondly, reduction in the extent of dipolar coupling between adjacent CO molecules again due to geometric dilution effect and, thirdly, an electronic effect leading to cationic Cu sites. The order of resistance of surface sites to modification with thiophene was Pd (bridging sites) > Pd (linear sites) > Cu+ > Cu. Multibonded CO on Pd remained after other forms of adsorbed CO on Pd and Cu had been displaced by the thiophene. Unlike CuSiO2 [G.J. Hutchings, F. King, I.P. Okoye, M.B. Padley, C.H. Rochester, J. Catal. 148 (1994) 453.] the PdCuSiO2 catalysts did not favour crotyl alcohol formation from crotonaldehyde hydrogenation over thiophene-modified catalysts because, as demonstrated by the infrared results, the Cu component was preferentially poisoned leaving active Pd sites which favoured C=C bond hydrogenation.

Fine particles in the atmosphere from soil and sand resuspension contain a variety of organic compounds from natural biogenic and anthropogenic matter. Soil and sand samples from various sites near Kuwait city were collected, sieved to retain the fine particles, and extracted with a mixture of dichloromethane and methanol. The extracts were derivatized and analyzed by gas chromatography-mass spectrometry in order to characterize the chemical compositions and sources of the organic components. The major inputs of organic compounds were from both natural biogenic and anthropogenic sources in these samples. Vegetation was the major natural source of organic compounds and included n-alkanols, n-alkanoic acids, n-alkanes, sterols and triterpenoids. Saccharides had high concentrations (31–43%) in the sand dune and seafront samples, indicating sources from decomposed vegation materials and/or the presence of viable microbiota such as bacteria and fungi. Vehicular emission products, leakage of lubricating oils, discarded plastics and emissions from cooking operations were the major anthropogenic inputs in the samples from the urban areas. This input was mainly UCM, n-alkanes, hopanes, plasticizers and cholesterol, respectively.

A comparative study of total grain protein was carried out by sodium dodecyle sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to characterise the differences between and within two species of wheat (Triticum aestivum and Triticum durum) represented by 12 cultivars. The densitometric profile data of the polypeptides showed an obvious variation in the number and position of bands from one cultivar to another. There were some bands in common between both species (103, 85, 70, 50, 46.9, 45, 40, 38, 34.1, 33, 31, 29, 28, 21, 20, 18, 14KD), while there were also some bands which characterise each species. Cladistic analysis showed that the four cultivars belonging to species T. aestivum/I> separated earlier in evolutionary history, and can be recognized from the rest of the cultivars which belong to species T. durum. KEY WORDS: Triticum aestivum,Triticum durum, protein polymorphism, electrophoresis, SDS-PAGE, cladistic analysis Egyptian Journal of Biology Vol.4 2002: 31-36

A keratinolytic, nocardioform actinomycete, strain D2(T), was isolated from Kuwait marsh soil by the bait technique using animal wool. Strain D2(T) was an aerobic, Gram-positive organism that produced light-grey aerial mycelium but no specific spore chains. 16S rDNA sequence analyses and chemotaxonomic markers were consistent with the classification of strain D2(T) in the genus Amycolatopsis, i.e. it had meso-diaminopimelic acid in its peptidoglycan, arabinose and galactose as its diagnostic sugars, the polar lipids phosphatidylinositol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine and diphosphatidylglycerol, menaquinone MK-9(H4) and an iso-/anteiso-branched fatty acid pattern combined with 10-methyl-branched and 2-hydroxy-branched fatty acids. Amycolatopsis japonica was the closest phylogenetic neighbour of strain D2(T), showing 99.4% 16S rDNA sequence similarity with the novel strain. A. japonica and strain D2(T) could be clearly separated from each other on the basis of their low DNA-DNA reassociation value (55.9%). These data, together with its distinct physiological traits, led to the conclusion that strain D2(T) represented a novel species within the genus Amycolatopsis, for which the name Amycolatopsis keratiniphila (type strain D2(T) = DSM 44409(T) = NRRL B24117(T)) is proposed.