515 research outputs found
Metabolism of archidonic acid by 5-lipoxygenase in guinea-pig lung
No full textPT: J; CR: BURKA JF, 1981, PROSTAG OTH LIPID M, V22, P683 BURKA JF, 1983, J PHARMACOL EXP THER, V225, P427 PARKER CW, 1982, BIOCHEM BIOPH RES CO, V109, P1011 SAAD MH, 1983, PROSTAGLANDINS, V25, P741 SAAD MH, 1984, EUR J PHARMACOL, V100, P13 SCHIANTARELLI P, 1981, EUR J PHARMACOL, V73, P363; NR: 6; TC: 6; J9: PROSTAGLANDINS; PG: 2; GA: TU225Source type: Electronic(1
Anatomical observations of Pseudomonas savastanoi on Rhamnus alaternus
No full textBuckthorn (Rhamnus alaternus) was recently reported as a new host of Pseudomonas savastanoi. The main symptom on buckthorn is the formation of knots on stems, branches and occasionally on leaves. Knot formation and anatomical changes in host tissues induced by P. savastanoi were studied macroscopically and by light microscopy. Inoculation of buckthorn shoots with P. savastanoi initiated small green swellings that developed into normal size knots. The pathogen invades intercellular spaces of parenchyma tissues degrading cell walls and resulting in extensive cavities filled with bacterial cells. Many host cells contiguous to such cavities were plasmolysed and necrotic. Depending on the depth of the inoculation wound, parenchyma, cambium, ray parenchyma, and pith cells close to bacterial cavities enlarge and proliferate forming the fully grown knots. At later stages of knot development, the cambium appears dispersed in the knot and forms unoriented vascular tissues. Periderm surrounds bacterial cavities and outer layers of knots. These findings on buckthorn are compared with those reported to be caused by the same pathogen on ash, oleander and olive. © 2007 The Authors.BRADBURY JF, 1986, GUIDE PLANT PATHOGEN, P172; GARDAN L, 1992, INT J SYST BACTERIOL, V42, P606; JANSE JD, 1982, EUR J FOREST PATHOL, V12, P218; Jensen WA, 1962, BOT HISTOCHEMISTRY P; Lelliot R. A., 1987, METHODS DIAGNOSIS BA; NICHOLSON RL, 1992, ANNU REV PHYTOPATHOL, V30, P369, DOI 10.1146-annurev.py.30.090192.002101; Ruzin S. E., 1999, PLANT MICROTECHNIQUE; Saad A. T., 2002, Phytopathology, V92, pS71; SAAD AT, 1992, MPU EPPO C OL DIS SO; SIEGFRIELD F, 1999, PATHOLOGICAL REGENER; SMITH EF, 1920, INTRO BACTERIAL DIS; SURICO G, 1985, PHYSIOL PLANT PATHOL, V26, P309, DOI 10.1016-0048-4059(85)90006-2; SURICO G, 1977, PHYTOPATHOL MEDITERR, V16, P109; TEMSAH M, 1991, CELL BIOL INT REP, V15, P611, DOI 10.1016-0309-1651(91)90008-7; WILSON EE, 1965, PHYTOPATHOLOGY, V55, P1244; WILSON EE, 1935, HILGARDIA, V4, P233; WILSON EE, 1964, PHYTOPATHOLOGY, V54, P57753
Histology of pathogenesis of Pseudomonas savastanoi on Myrtus communis
No full textMyrtle (Myrtus communis L.) is an evergreen shrub widely grown in the Mediterranean region for its aromatic leaves and medicinal uses. The bacterium Pseudomonas savastanoi was recently reported to attack this shrub with characteristic symptoms of knot formation on stems and branches leading, in severe cases, to their death. The pathogenesis of P. savastanoi on myrtle was studied macroscopically and by light microscopy. Inoculation of myrtle shoots with P. savastanoi initiated swellings that developed into knots typical of the disease. Starting from the inoculation wound, the bacteria spread into the intercellular spaces, invading and colonizing host tissues by degrading cell walls. They multiplied in the resulting cavities inducing hypertrophy and hyperplasia in the contiguous cells to form tissue masses that grew into knots. The size of a knot depended on the depth of the inoculation wound and more precisely on the parenchyma tissues involved, including those of the cortex, vascular tissues, and-or pith. At an advanced stage of invasion, the knot was composed of an aggregate of tissue masses within which xylem elements had differentiated. The knot became surrounded by wound periderm. Lignification of the parenchyma cells of the knot finally led to its hardening and death. These findings on myrtle were compared to those reported to be caused by the same pathogen on ash, buckthorn, oleander, and olive.ALONI R, 1987, ANNU REV PLANT PHYS, V38, P179; ALONI R, 1984, BOT GAZ, V145, P50, DOI 10.1086-337425; Bradbury J. F., 1986, GUIDE PLANT PATHOGEN; CORNELIA IU, 2000, J EXPT BOT, V51, P1951; GARDAN L, 1992, INT J SYST BACTERIOL, V42, P606; JANSE JD, 1982, EUR J FOREST PATHOL, V12, P218; Jensen WA, 1962, BOT HISTOCHEMISTRY P; Lelliot R. A., 1987, METHODS DIAGNOSIS BA; Ruzin S. E., 1999, PLANT MICROTECHNIQUE; Saad A. T., 2002, Phytopathology, V92, pS71; SAAD AT, 1992, MPU EPPO C OL DIS SO, P67; SMITH EF, 1920, INTRO BACTERIAL DIS; SURICO G, 1985, PHYSIOL PLANT PATHOL, V26, P309, DOI 10.1016-0048-4059(85)90006-2; SURICO G, 1977, PHYTOPATHOL MEDITERR, V16, P109; TEMSAH M, 2007, IN PRESS J FOREST PA; WALTON JD, 1994, PLANT PHYSIOL, V104, P1113; WILSON EE, 1965, PHYTOPATHOLOGY, V55, P1244; WILSON EE, 1935, HILGARDIA, V4, P233; WILSON EE, 1964, PHYTOPATHOLOGY, V54, P57788
Functionalized TUD-1: Synthesis, characterization and (photo-)catalytic performance
No full textThe new mesoporous material; TUD-1 is chosen of which the synthesis, characterization, and functionalization for (photo)-catalytic performance are extensively investigated in this study. The synthesis of the new catalytic materials M TUD-1 (M = Ti, V, Cr, Mo, Fe, Co and Cu) is carried out through an easy one-pot synthesis procedure, mainly depends on the addition of a small organic, cost-effective template triethanolamine together with the desired metal source and the silica source. The product; M-TUD-1 is a three-dimensional, open structured mesoporous siliceous material. The amount of metal added during the synthesis played the essential rule in the formation of different active site species (i.e. isolated, nano-particles and/or bulk crystals of metal oxide) in the TUD-1 matrix. The prepared materials are characterized by various characterization techniques (physical: X-ray diffraction, N2 sorption measurements SEM and HR-TEM and chemical: 29Si NMR, elemental analysis, and UV-VIS- and Raman spectroscopy). And their catalytic performance is tested in four different catalytic applications: selective photo-oxidation of propane, selective oxidation of cyclohexane, Friedel-Crafts benzylation of benzene, and laughing gas (N2O) decomposition. Indeed, the three-dimensional open structure of M-TUD-1 increases the accessibility to the active sites and hence, the (photo-)catalytic performance of M TUD-1 is ranked against their peers under comparable conditions: In the photo-oxidation of propane, Ti-TUD-1 exhibits a 2-2.5 times higher acetone selectivity than commercial TiO2. In the same reaction, Cr-TUD-1 is 5-6 times more active than SiO2 supported Cr at the same chromium loading. An important observation is that certain products (acetone, water) are less strongly adsorbed on TUD-1 than on zeolite-Y. In Friedel-Crafts benzylation of benzene, Fe-TUD-1 shows unique activity, which is benchmarked against other reported micro- (ZSM-5) and mesoporous systems (MCM-41 and HMS). In N2O decomposition, the activity reported over M-TUD-1 is less than reported for analogous M-ZSM-5. However, M-TUD-1 shows a better behaviour as a support than other mesoporous materials e.g. M-SBA-15, M-MCM-41. In conclusion, the present study shows that TUD-1 is not only just an interesting, but also an important support which can contain, in a controllable way, different active sites species, and that it can play a significant role in different catalytic application.Applied Science
A Methodology for Computational Architectural Design Based on Biological Principles
No full textBiomimicry, where nature is emulated as a basis for design, is a growing area of research in the fields of architecture and engineering. The widespread and practical application of biomimicry as a design approach remains however largely unrealized. A growing body of international research identifies various obstacles to the employment of biomimicry as an architectural design method. One barrier of particular note is the lack of a clear definition and methodology of the various approaches to biomimicry that designers can initially employ. This paper attempts to link biological principles with computational design in order to present a design methodology that aids interested architects within the preliminary design phase
Applications of well logging techniques to evaluate the groundwater aquifers in the area between southwest Bani Sweif and west Asyoute governorate, upper Egypt
No full textApplications of well logging techniques to evaluate the groundwateraquifers in the area between southwest Bani Sweif and west Asyoute governorate, upper Egypt Safi Eldein.M. Metwally 1, Shimaa. M. Elska 1, *, Fardous. M. Zarif 1, Abdallah. F. Saad 21 Dept. of geophysical exploration, Desert Research Center, Cairo, Egypt 2Dept of Physics., Faculty of Science, Zagazig University, Zagazig, Egypt *Corresponding author: [email protected] AbstractThe relevance of detecting aquifer characterization and aquifer potential has risen with the application of well logging technique as the demand for water has increased. Apart from pumping data, 16 geophysical well logs (resistivity, gamma ray, self-potential, and nuclear logs) are utilized to achieve the main goal of estimating petrophysical parameters (porosity (∅), effective porosity (∅!""), hydraulic conductivity (k), permeability (K) and shale volume
Laser thermal therapy: utility of interstitial fluence monitoring for locating optical sensors
No full textMultipoint optical fluence measurements can potentially be used to detect coagulation-induced changes in optical propagation during interstitial laser thermal therapy. Estimating the dimensions of coagulation using on-line optical monitoring, which is applicable to treatments where the tip of the source fibre is not precharred, may be limited by the accuracy of the placement of optical sensors with respect to source fibres. A strategy has been developed to determine accurately the position of a four-sensor linear array, prior to treatment, using optical fluence data obtained from the sensors for low-power (less than or equal to0.5 W) irradiation. A minimum of four sensors in an array was required in order to develop a mathematical formulation for position determination that did not require tissue optical properties or laser power as input. Optical propagation was based on diffusion theory for homogeneous tissues in spherical geometry. Low input laser power is needed to ensure that there are no thermally induced changes in tissue optical properties not accounted for in the mathematical description. Experimental evaluation was performed in a tissue-equivalent liquid phantom using 0.5 W of 805 nm optical energy and a translatable isotropic optical sensor. For sensor locations with 2 mm spacing, placement accuracy of 0.67 mm was achieved. The accuracy improved to 0.13 mm as the sensor spacing increased to 5 mm.PT: J; NR: 12; TC: 9; J9: PHYS MED BIOL; PG: 6; GA: 424AVSource type: Electronic(1
Slip at the surface of an oscillating spheroidal particle in a micropolar fluid
No full textThe axisymmetric rectilinear and rotary oscillations of a spheroidal particle in an incompressible micropolar fluid are considered. Basset type linear slip boundary conditions on the surface of the solid spheroidal particle are used for velocity and microrotation. Under the assumption of small amplitude oscillations, analytical expressions for the fluid velocity field and microrotation components are obtained in terms of a first order small parameter characterizing the deformation. For the rectilinear oscillations, the drag acting on the particle is evaluated and expressed in terms of two real parameters for the prolate and oblate spheroids. Also, the couple exerted on the spheroid is evaluated for the prolate and oblate spheroids for the rotary oscillations. Their variations with respect to the frequency, deformity, micropolarity and slip parameters are tabulated and displayed graphically. Well-known results are deduced and comparisons are made between the classical viscous fluids and micropolar fluids. The results of this study serve to improve the accuracy of viscosity measurements for micropolar fluids.
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