201 research outputs found
Ultrasonographic Appearance and Echo-pattern Characterization of Donkeys’ Internal Reproductive Organs
The current study was achieved to designate the accessory sex glands, ampullae and urethra of 25 healthy male donkeys using the ultrasonography. Animals were classified according to their age into young peri-mature (i.e. ≤2 years; n=7) and old mature (>3 years; n=18). The examination was done per rectum by using Magic 2200 scanner with a 6 MHz linear transrectal transducer. The position of each gland was allocated, and length and width were measured. The dimensions of prostate gland lobes and ampulla ductus deferens significantly differed between the examined groups. The echo-pattern analysis of vesicular gland and ampulla ductus deferens, in terms of mean pixel value (MPV), pixel intensity (PI) and pixel number (PN), significantly differed between premature and mature donkeys. Age was significantly correlated with all sex glands measurements. There was a substantial confident relationship between MPV and PI and the dimensions of vesicular and ampulla ductus deferens. In the meantime, PN was clearly negatively correlated with vesicular gland length and width. In conclusions, ultrasound is a feasible non-invasive diagnostic tool that could be used to characterize the accessory glands along the course of the pelvic urethra of male donkeys reared in Egypt. The addressed measures as well as acoustic physiognomies of the secondary sex organs are considered a promising guide in fertility potential prediction and/or the discrimination of the pathological conditions of male reproductive organs
Visible Light Driven Hydrogen Evolution with a Noble Metal Free CuGaInS Nanoparticle System in Water
CuGaInS (CGIS) nanoparticles were synthesised by a hot-injection method and rendered water dispersible by modification with the hydrophilic ligand 3-mercaptopropionic acid (MPA). The CGIS nanoparticles were characterised by X-ray diffraction, transmission electron microscopy, X-ray photoelectron, diffuse reflectance and infrared spectroscopy as well as inductively coupled plasma optical emission spectroscopy. Photocatalytic H production using the MPA modified CGIS nanoparticles and a nickel salt under visible light irradiation was achieved from acidic solution (pH 2.6) with ascorbic acid as a sacrificial electron donor. Previously, CGIS required the presence of a precious metal co-catalyst and sulfide ions as a sacrificial reagent in alkaline solution to display photocatalytic activity for H generation. In the reported system, visible light irradiation of the MPA modified CGIS nanoparticles with a Ni salt displayed even superior sacrificial H evolution activity than when employing the precious metals Pt, Rh and Ru. An external quantum efficiency of more than 12% was achieved at λ = 540 nm, which is almost twice that previously reported for CGIS nanoparticles in the presence of a noble metal co-catalyst and sulfide ions as an electron donor.T.A.K.
thanks
the
Science
and
Technology
Development
Fund
(STDF)
of
the
Arab
Republic
of
Egypt
and
the
British
Council
at
Cairo
for
financially
supporting
his
visit
to
the
University
of
Cambridge,
UK.
G.A.M.H.
was
supported
by
a
Cambridge
Trust
/
Australia
Poynton
PhD
scholarship.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry at http://dx.doi.org/10.1039/C6CY01103A
Mesoporous TiO2 nanostructures: A route to minimize Pt loading on titania photocatalysts for hydrogen production
Mesostructured TiO2 nanocrystals have been prepared using Pluronic F127 as the structure-directing agent. Platinum nanoparticles at different contents (0.1-1.0 wt%) have been photochemically deposited onto the mesoporous TiO2. TEM investigation of 0.2 wt% Pt/TiO2 calcined at 450 °C reveals that the TiO2 particles are quite uniform in size and shape with the particle sizes of TiO2 and Pt being 10 and 3 nm, respectively. The photocatalytic activities of the Pt loaded TiO2 have been assessed and compared with those of nonporous commercial Pt/TiO2-P25 by determining the rates and the photonic efficiencies of molecular hydrogen production from aqueous methanol solutions. The results show that the amount of hydrogen evolved on Pt/TiO2-450 at low Pt loading (0.2 wt%) is three times higher than that evolved on Pt/TiO2-P25 and twelve times higher than that evolved on Pt/TiO 2-350. Despite the BET surface area of the TiO2-450 photocatalyst being 3.5 times higher than that of TiO2-P25, a 60% smaller amount of the Pt co-catalyst is required to obtain the optimum photocatalytic hydrogen production activity. The reduced Pt loading on the mesoporous TiO2 will be important both from a commercial and an ecological point of view. © 2011 the Owner Societies
Long-term investigation of the photocatalytic hydrogen production on platinized TiO2: an isotopic study
Long-term investigations of the photocatalytic hydrogen production on platinized TiO2 photocatalysts have been carried out employing different solutions of (deuterated) water and (deuterated) methanol. The results indicate that methanol acts as a sacrificial reagent, i.e., as an “electron donor” and that the amount of evolved molecular hydrogen is equivalent to the amount of H2 expected from the complete reforming of methanol or even less depending on the used photocatalyst. No evidence for photocatalytic water splitting is observed even in the presence of very low methanol concentrations, i.e., no molecular oxygen has been detected. Based upon the isotopic labelling studies it was confirmed that H2 is mainly produced by the reduction of protons originating from water.BMBF/HyCats/01RC1012
Brookite versus anatase TiO2 photocatalysts: Phase transformations and photocatalytic activities
Titanium dioxide nanoparticles consisting of pure anatase, anatase-rich, brookite-rich, and pure brookite modifications were synthesized and characterized by X-ray diffraction, field emission-scanning electron microscopy and nitrogen adsorption. The phase transformations among the three modifications of TiO2 (anatase, brookite, and rutile) and the photocatalytic activities of these nanoparticles were investigated by heat treatment over the temperature range from 400 to 800 °C and by the photooxidation of methanol, respectively. Direct transformation of anatase and brookite to rutile was observed, while in the case of the anatase–brookite mixture, anatase transforms firstly to brookite and then to rutile. The photocatalytic activity measurements indicate that brookite nanoparticles exhibit higher photocatalytic activities than anatase, and a comparable activity to that of the anatase-rich nanoparticles. The phase transformations and photocatalytic results are discussed regarding their dependence on crystallite size, surface area, and phase composition
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Structure-activity relationships of hierarchical three-dimensional electrodes with photosystem II for semi-artifcial photosynthesis
Semi-artificial photosynthesis integrates photosynthetic enzymes with artificial electronics, which is an emerging approach to reroute the natural photoelectrogenetic pathways for sustainable fuel and chemical synthesis. However, the reduced catalytic activity of enzymes in bioelectrodes limits the overall performance and further applications in fuel production. Here, we show new insights into factors that govern the photoelectrogenesis in a model system consisting of photosystem II and three-dimensional indium tin oxide and graphene electrodes. Fluorescence microscopy and in situ surface-sensitive infrared spectroscopy are employed to probe the enzyme distribution and penetration within electrode scaffolds of different structures, which is further correlated with protein film-photoelectrochemistry to establish relationships between the electrode structure and enzyme activity. We find that the hierarchical 1 structure of electrodes mainly affects the protein integration, but not the enzyme activity. Photoactivity is more limited by light intensity and electronic communication at the biointerface. This study provides guidelines for maximizing the performance of semi-artificial photosynthesis and also presents a set of methodologies to probe the photoactive biofilms in three-dimensional electrodes.CSC-Cambridge PhD Scholarship, EPSRC PhD studentship, Newton-Mosharafa Research Fellowship, ERC Consolidator Grant 'MatEnSAP
Ciprofloxacin and levofloxacin adversely affect male infertility indicated by pharmacological, andrological and pathological evidence
Background: Drug-induced reproductive organs toxicities is an important aetiology in investigation of male infertility. The aim is to study levofloxacin effect on male reproductive system in comparison to ciprofloxacin.Methods: Twenty-five male wister rats weighted 230±20 gm and aged 8 weeks were randomly divided into five groups of five. The first group received ciprofloxacin with dose 78.23 mg/kg/day in 2 doses (therapeutic dose). The second group received the double dose of the first group ciprofloxacin. The third group received levofloxacin with dose 39.11 mg/kg/day once daily (OD) (therapeutic dose). The Fourth group received the double dose of the third group levofloxacin. However, the fifth group served as a control and received normal saline with carboxymethylcellulose OD. All treatments were administered orally for 14 days. On the 15th day, blood samples and reproductive organs were obtained from all rats. Testicular tissues were prepared for genetic testing and chemical and microscopical examination.Results: Ciprofloxacin and levofloxacin negatively altered reproductive organ weights, sperm parameters and serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) level (p<0.05). Additionally, serum testosterone level was significantly deceased in ciprofloxacin-treated group (the double dose) (p<0.05) relative to control. The difference between ciprofloxacin and levofloxacin was significant in seminal vesicle weight and serum LH and FSH level (p<0.05). Testicular histopathological changes were also found with the two drugs with different degrees. Effects of levofloxacin and ciprofloxacin were dose-dependent.Conclusions: Both ciprofloxacin and levofloxacin adversely affect andrological function that should be monitored and controlled during application of these drugs
Gentamicin and amikacin adversely affect male infertility indicated by pharmacological, andrological and pathological evidence
Background: Many drugs are implicated in male infertility and screening for medication history is an important for diagnosis and treatment of the problem. The aim is to study amikacin effect on male reproductive system in comparison to gentamicin.Methods: Twenty-five male wister rats weighted 220±20 gm and aged 8 weeks were randomly divided into five groups of five. The first group received gentamicin in dose 18.25 mg/kg/day once daily (OD) (therapeutic dose). The second group received gentamicin with double dose of the first group. The third group received amikacin in dose 54.75 mg/kg/day OD (therapeutic dose). The Fourth group received amikacin with double dose of the third group. However, the fifth group served as a control and received normal saline (NS) OD. All treatments were administered intraperitoneally (IP) for 14 days. On the 15th day, blood samples and reproductive organs were obtained from all animals. Testicular tissues were prepared for genetic testing and chemical and microscopical examination.Results: Amikacin and gentamicin negatively affected reproductive organs weights, sperm parameters, serum follicle stimulating hormone and luteinizing hormone (LH) level relative to control (p<0.05). However, serum testosterone level was only affected with gentamicin (p<0.05). A significant difference between gentamicin and amikacin was found in sperm count, testis and epididymis weights and serum testosterone and LH level (p<0.05). Testicular histopathological changes were also found with the two drugs with different degrees. Effects of both gentamicin and amikacin were dose-dependent.Conclusions: Both gentamicin and amikacin adversely affect andrological function that should be monitored and controlled during application of these drugs
Histomorphometry aspect of thyroid gland and biochemical profile in pregnant and non-pregnant dromedary camels
Modulation of body physiology and metabolism is a prerequisite for successful pregnancy in camels, which is about a year and few months. The present study was carried out to verify the effect of pregnancy on histomorphometry and functional traits of thyroid gland, as well as some biochemical indices of liver and kidney functions and mineral profile in one humped camels, under Egyptian climatic conditions or desert conditions. The thyroid tissues were fixed in 10% formalin solution and processed following routine histological techniques after gross examination and biometric assessment. Serum levels of thyroid hormones (triiodothyronine, thyroxineand thyroid stimulating hormone), serum blood metabolites (total bilirubin, blood urea nitrogen and creatinine), liver enzymatic activity (aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP)), and minerals (sodium, potassium, calcium and phosphorus) were estimated in pregnant (n=30) and non-pregnant (n=30) camels. There were no significant differences between the right and left thyroid lobes between pregnant and non-pregnant camel. Pregnant status in camels had insignificant influence on histological and functional traits of thyroid as well as serum blood metabolites, liver enzymes and minerals levels, as compared with non-pregnant animals during the first six months of pregnancy. Therefore, reproductive status (during early pregnancy) has no substantial effect on camel physiological mechanisms or metabolic activity.Key words: Biochemical, dromedary, histology, thyroid gland, thyroid hormones
Comparison of characteristics of selected metallic and metal oxide nanoparticles produced by picosecond laser ablation at 532 and 1064Â nm wavelengths
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