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  • Polymer and Materials Science  (5)
  • DNA flowcytometry  (3)
  • Engineering  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Fertility and unilateral undescended testis in the rat model II (1998)
    Springer
    Pediatric surgery international 13 (1998), S. 392-395 
    Details
    ISSN: 1437-9813
    Keywords: Key words Fertility ; Unilateral undescended testis ; DNA flowcytometry ; Anti-sperm antibodies ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Continuing experimental work on the effect of experimentally created unilateral undescended testis (UL-UDT) in neonatal rats, this study examined the fertility and correlated it to contralateral (CL) testicular morphology, seminiferous tubular diameter (STD), DNA flowcytometry, and the presence of serum anti-sperm antibodies (ASA) at 120–135 days of age. In our previous reported work, the fertility of rats with UL-UDT at 65–80 days of age was the same as that of controls. In the present study the rats with UL-UDT had significantly reduced fertility (P 〈 0.01) compared to controls, even though the Johnsen scores and mean STD of the CL testicular tissue were comparable. DNA flowcytometry demonstrated a significant decrease (P 〈 0.001) in haploid cell population in the CL testicular tissue of rats with UL-UDT. Furthermore, the rats with UL-UDT who either received an immunosuppressive or in whom the UDT was excised early showed almost normal fertility and DNA histograms like those of controls. Significantly high titres of serum ASA were detected only in the group with UL-UDT when tested at 135 days of age. From these results, in combination with earlier results on similar work, it may be inferred that UL-UDT causes immunologically-mediated, progressive damage to the CL descended testis, leading to a decrease in fertility in rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003830050347
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of cyclosporine on fertility in male rats (1998)
    Springer
    Pediatric surgery international 13 (1998), S. 388-391 
    Details
    ISSN: 1437-9813
    Keywords: Key words Cyclosporine ; Male fertility ; DNA flowcytometry ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of cyclosporine (CsA) on fertility has assumed greater importance with the increasing numbers of pediatric transplantations being performed all over the world. Conflicting reports on the effects of CsA on sex hormones are available. This experimental animal study was designed to examine the effect of CsA on testicular weight, sperm counts, seminiferous tubular diameter (STD), testicular morphology, DNA flowcytometry, sex hormone levels, and fertility in male rats. Those rats who received CsA (20 mg/kg per day) showed significant reductions in testicular weight (P 〈 0.05), sperm count (P 〈 0.01), Johnsen score (P 〈 0.05), STD (P 〈 0.01), serum testosterone levels (P 〈 0.05), haploid cell population (P 〈 0.001) in the testis, and fertility (P 〈 0.001) compared to those receiving CsA 10 mg/kg per day and control rats. These findings will have an important bearing for children receiving cyclosporine for long periods to guide the physician in optimally adjusting long-term treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003830050346
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  • 3
    Electronic Resource
    Electronic Resource
    Experimental unilateral undescended testis: gubernaculectomy and anchoring or direct suture fixation? (1999)
    Springer
    Pediatric surgery international 15 (1999), S. 461-464 
    Details
    ISSN: 1437-9813
    Keywords: Key words Unilateral undescended testis ; Rat ; Testicular injury ; DNA flowcytometry ; Anti-sperm antibody
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study was designed to evaluate whether creation of a unilateral undescended testis (U/L UDT) in rats by direct fixation of the testis can lead to changes in the contralateral (C/L) descended testis, and if so, whether this inherent problem of the model could be eliminated by anchoring the divided gubernaculum to indirectly fix the testis. Thirty male newborn rats were divided into three groups of 10 each and the procedure done on the 2nd day of life to create U/L UDT according to the group allocated: group I: sham-operated; group II: anchoring the gubernaculum after gubernaculectomy; group III: Direct suture fixation of the testis. Fertility, C/L testicular weight (TW), Johnsen score, seminiferous tubular diameter (STD), DNA flowcytometry, and serum anti-sperm antibodies (ASA) were studied. Fertility, C/L TW, Johnsen score, STD, and haploid cell population were significantly reduced in group III compared to group II, while significantly higher titers of ASA were found in group III. Gubernaculectomy and anchoring the gubernaculum to the anterior abdominal wall is a better technique of creation of experimental UDT, as direct fixation of the testis is potentially detrimental to the C/L normal, descended testis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003830050638
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  • 4
    Electronic Resource
    Electronic Resource
    Small-angle X-ray scattering of cellulose. I. Shape and extent of scattering in some vegetable fibers (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 3427-3437 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: It was shown that the shape of the scattering pattern is not only related to the shape but also to the face-orientation of the lamellar scattering units, and an actual observation of its characteristic shape depends on the amount and dispersion of their spiral angle. The following results were obtained: (1) For observing a cross-pattern, the critical spiral angles corresponding to minimum and maximum dispersions are 7.5° and 30° respectively, whereas in an actual fiber, coir, the critical angle is about 16.75°. (2) The jute pattern changes from a uniformly narrow to a triangular shape on disorientation and reverts to the former on reorientation. The corresponding changes in ramie are from a triangular to a uniformly wide and then to a uniformly narrow shape. Both native and disoriented cottons give weak, fan-shaped scattering superimposed on a more intense elliptical pattern. The pattern given by reoriented cotton is roughly a narrow streak. Delignified jute gives a somewhat shaving-brush-shaped pattern which changes to a uniformly wide streak on alkali treatment. (3) The extent of scattering decreases on swelling and increases on stretching in jute, ramie, and cotton, but decreases in stretched coir.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070091020
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  • 5
    Electronic Resource
    Electronic Resource
    S-benzoyl O-ethyl xanthate as a new photoinitiator: Photopolymerization and laser flash photolysis studiesContribution No. NDRL-3423 from the Notre Dame Radiation Laboratory and No. RRL-PRU-22 from the Regional Research Laboratory, Trivandrum. (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 653-659 
    Details
    ISSN: 0887-624X
    Keywords: photopolymerization ; photoinitiator ; aroyl xanthates ; methyl methacrylate ; laser flash photolysis ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new sulfur-containing photoinitiator, S-benzoyl O-ethyl xanthate (2) has been prepared and used for the photopolymerization of methyl methacrylate (MMA). The photoinitiation property of 2 has been examined by conventional polymerization methods and nanosecond laser flash photolysis studies. Upon 308 nm laser pulse excitation, 2 gave rise to transients with absorption maxima at 350 and 650 nm, assigned to the benzoyl radical (3) and (ethoxythiocarbonyl)thiyl radical (4), respectively, on the basis of their quenching by nitroxy radicals and spectral similarity to analogous species, reported in the literature. © 1993 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310308
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  • 6
    Electronic Resource
    Electronic Resource
    Computational modelling of thermal transport phenomena in continuous casting process based on non-orthogonal control volume approach (1996)
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 12 (1996), S. 657-671 
    Details
    ISSN: 1069-8299
    Keywords: continuous casting ; free boundary problem ; co-ordinate transformation ; solidification front ; non-orthogonal control volume ; temperature profile ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An efficient computational simulation scheme based on non-orthogonal control volume discretization and co-ordinate transformation techniques has been developed for solving the thermal transport phenomena, which involves tracking of the interface between solid and liquid phases (solidification front) and evaluation of the temperature profile during continuous casting operation. Conservation equations are reformulated in differential-integral form in terms of the transformed co-ordinates. All the terms arising from the non-orthogonality of the control volume have been retained in the numerical solution methodology, and a front tracking procedure has been formulated based on an iterative solution scheme. The formulation has been applied to solve the thermal transport phenomena in solidification processing of an A1-Mg alloy cylindrical ingot during continuous casting, which also includes axial conduction of heat. Theoretical evaluation of the solidification front and temperature distribution in the ingot are in good agreement with the experimentally measured data.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Photografting of acrylic monomers on polystyrene support (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 45 (1992), S. 1617-1622 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Polystyrene xanthates, prepared through the reaction of chloromethylated polystyrene resins with potassium O-ethyl xanthate, have been used for the photografting of acrylic monomers. Monomers such as acrylamide, acrylic acid, methacrylic acid, and methyl methacrylate were grafted onto the xanthate polymers on irradiation with a 450 W medium-pressure mercury lamp (Hanovia). Among these monomers, the maximum graft efficiency was obtained for methyl methacrylate. The effect of cross-link density of the xanthate polymer on the percentage graft yield was also studied. Scanning electron microscopic studies have shown that appreciable grafting has taken place on the surface of the polymer in a uniform manner. © 1992 John Wiley & Sons, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070450912
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  • 8
    Electronic Resource
    Electronic Resource
    Small-angle X-ray scattering of cellulose. II. Intensity of scattering in some fibers and films (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 3439-3450 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: It was shown that the realization of a straight log I-h2 curve may be a coincidence depending on the relative influence of heterogeneity of distribution and non-independent scattering, and a concave log I-h2 curve can represent a nonhomogeneous system amenable to Shull and Roess's method of analysis. The results indicate: (1) The I-h curve for a jute holo-cellulose film has a maximum, and that for a ramie film an inflexion point, each superimposed on a background of gradually declining intensity, and in either case the singularity is accentuated and shifted to a region of larger angle on alkali-treatment. (2) The log I-h2 plots for untreated, alkali-treated and stretched jute fibers give straight sections in the low-angle, and convex, concave, and straight sections, respectively, in the high-angle region. An interesting feature of the results for ramie is the realization of a straight logarithmic curve on mercerization. The curves for alkali-treated and stretched Fortisan fibers have also each of them two discernible linear parts, indicative of two groups of scatterers. (3) An evaluation of the log I-log h2 curves by Shull and Roess's method leads to figures for the diameters of the scattering elements in ramie comparable to those estimated from the corresponding log I-h2 plots.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070091021
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  • 9
    Electronic Resource
    Electronic Resource
    Variational parameter estimation for a two-dimensional numerical tidal model (1992)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 15 (1992), S. 313-327 
    Details
    ISSN: 0271-2091
    Keywords: Numerical tidal model ; Data assimilation ; Parameter estimation ; Optimal control ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: It is shown that the parameters in a two-dimensional (depth-averaged) numerical tidal model can be estimated accurately by assimilation of data from tide gauges. The tidal model considered is a semi-linearized one in which kinematical non-linearities are neglected but non-linear bottom friction is included. The parameters to be estimated (bottom friction coefficient and water depth) are assumed to be position-dependent and are approximated by piecewise linear interpolations between certain nodal values. The numerical scheme consists of a two-level leapfrog method. The adjoint scheme is constructed on the assumption that a certain norm of the difference between computed and observed elevations at the tide gauges should be minimized. It is shown that a satisfactory numerical minimization can be completed using either the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton algorithm or Nash's truncated Newton algorithm. On the basis of a number of test problems, it is shown that very effective estimation of the nodal values of the parameters can be achieved provided the number of data stations is sufficiently large in relation to the number of nodes.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650150305
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  • 10
    Electronic Resource
    Electronic Resource
    Optimal estimation of eddy viscosity for a quasi-three-dimensional numerical tidal and storm surge model (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 18 (1994), S. 295-312 
    Details
    ISSN: 0271-2091
    Keywords: Variational data assimilation ; Parameter estimation ; Numerical tidal model ; Eddy viscosity ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: It is shown that the eddy viscosity profile in a quasi-three-dimensional numerical tidal and storm surge model can be estimated by assimilation of velocity data from one or more current meters located on the same vertical line. The computational model used is a simplified version of the so-called vertical/horizontal splitting algorithm proposed by Lardner and Cekirge. We have estimated eddy viscosity both as a constant and as a variable parameter. The numerical scheme consists of a two-level leapfrog method to solve the depth-averaged equations and a generalized Crank-Nicolson scheme to compute the vertical profile of the velocity field. The cost functional in the adjoint scheme consists of two terms. The first term is a certain norm of the difference between computed and observed velocity data and the second term measures the total variation in the eddy viscosity function. The latter term is not needed when the data are exact for the model but is necessary to smooth out the instabilities associated with ‘noisy’ data. It is shown that a satisfactory minimization can be accomplished using either the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton algorithm or Nash's truncated Newton algorithm. Very effective estimation of eddy viscosity profiles is shown to be achieved even when the amount of data is quite small.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650180305
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