Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Sex differences in geometry of the femoral neck with aging: A structural analysis of bone mineral data (1992)
    Springer
    Calcified tissue international 50 (1992), S. 24-29 
    Details
    ISSN: 1432-0827
    Keywords: Bone mineral analysis ; Hip strength analysis ; Age ; Femoral neck stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The greater hip fracture rate among elderly women is generally ascribed to differences in femoral neck strength between the sexes. Strength of a given bone is a function of both its material properties and the magnitudes of mechanical stresses within it. This study examined the hypothesis that these apparent strength differences between the sexes are due to dissimilarities in the restructuring of the femoral neck with age, which result in higher stresses in elderly women. Using Hip Strength Analysis, a computer program developed by the authors, femoral neck cross-sectional geometric properties for stress analyses were derived from bone mineral image data of 409 community living, white subjects ranging from 19 to 93 years of age. Though both sexes show declines in femoral neck bone mineral density (BMD) and cross-sectional area with age, only females show a decline in the cross-sectional moment of inertia (CSMI, a geometric index of bone rigidity). The lack of decline in male CSMI appears to be a result of a small but significant increase in femoral neck girth. Similar age-related changes have been observed in the femoral shaft by others. The net effect of these observed changes is that mechanical stresses in the femoral neck of females appear to increase at three times the rate per decade of those of males. These results lend support to the hypothesis that the higher fracture rate in elderly women is due, at least in part, to elevated levels of mechanical stress, resulting from a combination of greater bone loss and less compensatory geometric restructuring with age.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297293
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Nitrogen availability to grain sorghum from organic and inorganic sources on sandy and clayey soil surfaces in a greenhouse pot study (1996)
    Springer
    Biology and fertility of soils 21 (1996), S. 271-276 
    Details
    ISSN: 1432-0789
    Keywords: Key words15N transformations ; Crop residues ; Soil texture ; Soil aggregation ; Microbial pool ; Microbial biomass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In a greenhouse pot study, we examined the availability of N to grain sorghum from organic and inorganic N sources. The treatments were 15N-labeled clover residues, wheat residues, and fertilizer placed on a sandy clay loam and loamy sand soil surface for an 8-week period. Soil aggregates formed under each soil texture were measured after 8 weeks for each treatment. Significantly greater 15N was taken up and recovered by grain sorghum in sandy clay loam pots compared with loamy sand pots. Greater 15N recovery was consistently observed with the inorganic source than the organic sources regardless of soil texture or time. Microbial biomass C and N were significantly greater for sandy clay loam soil compared with the loamy sand. Microbial biomass 15N was also significantly greater in the sandy clay loam treatment compared to the loamy sand. The fertilizer treatment initially had the greatest pool of microbial biomass 15N but decreased with time. The crop residue treatments generally had less microbial biomass 15N with time. The crop residues and soil texture had a significant effect on the water-stable aggregates formed after 8 weeks of treatments. Significantly greater water-stable aggregates were formed in the sandy clay loam than the loamy sand. Approximately 20% greater water-stable aggregates were formed under the crop residue treatments compared to the fertilizer only treatment. Soil texture seemed to be one of the most important factors affecting the availability of N from organic or inorganic N sources in these soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334903
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Nitrogen availability to grain sorghum from organic and inorganic sources on sandy and clayey soil surfaces in a greenhouse pot study (1996)
    Springer
    Biology and fertility of soils 21 (1996), S. 271-276 
    Details
    ISSN: 1432-0789
    Keywords: 15N transformations ; Crop residues ; Soil texture ; Soil aggregation ; Microbial pool ; Microbial biomass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In a greenhouse pot study, we examined the availability of N to grain sorghum from organic and inorganic N sources. The treatments were15N-labeled clover residues, wheat residues, and fertilizer placed on a sandy clay loam and loamy sand soil surface for an 8-week period. Soil aggregates formed under each soil texture were measured after 8 weeks for each treatment. Significantly greater 15N was taken up and recovered by grain sorghum in sandy clay loam pots compared with loamy sand pots. Greater 15N recovery was consistently observed with the inorganic source than the organic sources regardless of soil texture or time. Microbial biomass C and N were significantly greater for sandy clay loam soil compared with the loamy sand. Microbial biomass 15N was also significantly greater in the sandy clay loam treatment compared to the loamy sand. The fertilizer treatment initially had the greatest pool of microbial biomass 15N but decreased with time. The crop residue treatments generally had less microbial biomass 15N with time. The crop residues and soil texture had a significant effect on the water-stable aggregates formed after 8 weeks of treatments. Significantly greater water-stable aggregates were formed in the sandy clay loam than the loamy sand. Approximately 20% greater water-stable aggregates were formed under the crop residue treatments compared to the fertilizer only treatment. Soil texture seemed to be one of the most important factors affecting the availability of N from organic or inorganic N sources in these soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334903
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    High speed molecular weight distribution (1975)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 15 (1975), S. 831-833 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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 is now possible to do molecular weight distribution of polymeric material almost as fast as you can put them in solution. μSYRAGEL® has opened a new era in the determination of molecular weight distribution of polymers. With operational efficiencies of 800 plates/min., one can obtain a molecular weight distribution in 15 mins. Combining three of the newest advances in liquid chromatography - solvent delivery, septumless injection, and μSYRAGEL - now makes it possible to use molecular weight distribution as a quality control tool in polymerization and fabrication. The reproducibility of the molecular weight distribution is now good enough that overlays can be done from the raw data. The chromatograms can be used right off the recorder. The reproducibility of the weight average and number average molecular weight is 2-3 percent.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760151203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Hydrodynamic properties of polyelectrolytes. Part II. Poly-4-vinylpyridine (1956)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 21 (1956), S. 473-482 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The hydrodynamic properties of fractionated samples of poly-4-vinylpyridine have been studied. The intrinsic viscosities and the Huggins' constant (k′) have been obtained. The effect of shear on the viscosity disappears at high dilution. The sedimentation constants (S0) have been measured, and the streaming birefringence has been investigated at various concentrations and shear gradients. The Peterlin theory for concentrated solutions is in good agreement with the results for the orientation angle, but is not so well in accord with the magnitude of the birefringence. The partial specific volume is low (0.685). Molecular weights have been calculated for the fractions, and it is concluded that the shape of the molecules in solution approximates to that of a stiff coil.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1956.120219911
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The sedimentation and diffusion of sodium polymethacrylate and polymethacrylic acid (1954)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 12 (1954), S. 209-219 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The sedimentation constants and diffusion coefficients of sodium polymethacrylate and of polymethacrylic acid have been determined at various concentrations of polymer and of added electrolyte and the nature of the charge effects is considered. A ratio y = (molarity of added electrolyte)/(grundmolarity of polymer) is used to obtain S20 at y = ∞ when the polyelectrolyte is assumed to be uncharged. The variation of the effective radius with y is considered not to be due to asymmetry but to the open network nature of the polyelectrolyte coil.The sedimentation constant of unionized polymethacrylic acid is determined and also the variation of sedimentation constant with degree of ionization.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1954.120120117
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Hydrodynamic properties of polyelectrolytes. Part I. Poly-4-vinyl-N-n-butylpyridinium bromide (1956)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 21 (1956), S. 463-472 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The viscosity, streaming birefringence, and sedimentation of a sample of poly-4-vinyl-N-n-butylpyridinium bromide have been measured in aqueous and in sodium chloride solutions. The theory of Peterlin for concentrated solutions has been found to be in agreement with the results. Values of the molecular weight have been calculated by different methods and a value of 9 × 105 has been chosen.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1956.120219910
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Solution viscosity and molecular weight of polystyrene prepared by aluminium chloride catalysis (1952)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 9 (1952), S. 286-288 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1952.120090312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The kinetics of the renaturation of deoxyribonucleic acid denatured in the presence of copper (II) ions (1972)
    New York : Wiley-Blackwell
    Biopolymers 11 (1972), S. 1661-1684 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: DNA which has been heat denatured in the presence of Cu++ ions can be completely and rapidly renatured by increasing the ionic strength of the solution above a critical value. A kinetic study of this renaturation recation was carried out by following the associated UV absorbance change and also by following the change in free Cu++ ion concentration by means of a specific Cu++ ion activity electrode. The data obtained could be fitted to first-order kinetics for a considerable extent of the reaction and the rate constant was found to increase with temperature and ionic strength, but to decrease markedly as the bulk viscosity of the solution was increased. At temperatures greater than 5°C the reaction rate depended on the time elapsing between denaturation and the commencement of the renaturation reaction. As there was good agreement between the rate constants obtained by following the decrease in hyperchromism and by following the increase in free Cu++ ion concentration, it is concluded that under the conditions employed, the rate of renaturation is determined by the rate of release of Cu++ ions from the denatured DNA-Cu++ complex.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1972.360110812
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Interaction of proflavine and 9-aminoacridine with DNA at temperatures below and above the melting temperature (1971)
    New York : Wiley-Blackwell
    Biopolymers 10 (1971), S. 399-410 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The influence of temperature on the binding of 9-aminoacridine and of proflavine to E. coli DNA in 10-3M NaCl solution has been determined by a spectrophotometric technique. The inadequacy of the expression normally used for the determination of the extent of binding is discussed with reference to measurements at temperatures above which dissociation of the double helix occurs. A method of determining the relative extents of binding to native and denatured DNA at elevated temperatures is described.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360100214
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...