scholarly journals Determination of Auxin-Dependent pH Changes in Coleoptile Cell Walls by a Null-Point Method

1993 ◽  
Vol 103 (2) ◽  
pp. 351-357 ◽  
Author(s):  
P. Schopfer
Keyword(s):  
Cell Walls ◽  
Null Point ◽  
Point Method ◽  
Ph Changes

An experimental evaluation of simplified procedures for determining the proton spin–lattice relaxation rates of natural products

1980 ◽  
Vol 58 (19) ◽  
pp. 2016-2023 ◽  
Author(s):  
Lawrence D. Colebrook ◽  
Laurance D. Hall
Keyword(s):  
Natural Products ◽  
Lattice Relaxation ◽  
Null Point ◽  
Proton Spin ◽  
Computational Method ◽  
Spin Lattice Relaxation ◽  
Relaxation Rates ◽  
Spin Lattice ◽  
Simplified Procedures

A general discussion is given of the determination of the proton spin–lattice relaxation rates of natural products, with particular emphasis on use of the null-point method which, for the systems studied here, gives identical results with those obtained via the conventional (and relatively time consuming) computational method.

scholarly journals Comparative pharmakognostical study of roots of Rosa Majalis Herrm. and Rosa Canina L.

2021 ◽  
pp. 71-78
Author(s):  
Tetiana Oproshanska ◽  
Olga Khvorost ◽  
Kateryna Skrebtsova ◽  
Konradas Vitkevicius
Keyword(s):  
Cell Walls ◽  
Raw Materials ◽  
Total Polyphenols ◽  
Diagnostic Features ◽  
Rosa Canina ◽  
Plant Raw Materials ◽  
Quantitative Content ◽  
Microscopic Features ◽  
Boundary Limits

The aim is to conduct a comparative pharmacognostical study of the series of roots of Rosa (R.) majalis Herrm. and Rosa (R.) canina L. with the establishment of diagnostic features of morphological and anatomical structure and boundary limits of numerical indicators of raw materials. Materials and methods. The fresh and dry raw materials were used to study the macroscopic microscopic features by microscope Delta optical BioLight 300 (Poland). Determination of total polyphenols was performed by spectrophotometry (on a spectrophotometer Optizen POP (Korea)) and HPLC (chromatograph an Agilent 1200 3 D LC System Technologies (USA)). Results. The morphological (nature of the surface (periderm) and fracture) and anatomical (color of cell walls and their cavities; location of the sclerenchyma; the presence of a crystalline coating of the sclerenchyma at the root of R. canina; of various elements of the remains of the tetraarchic conducting bundle in the center of the root) diagnostical features of roots of R. majalis and R. Canina were established. Comparing the numerical values of loss on drying (not more than 10 %), total ash (not more than 5 %), extractable matter (not less than 9 %) and the quantitative content of total polyphenols (not less than 4 %) it was determined that both types of raw materials according to these indicators are almost indistinguishable. Conclusions. Loss on drying, total ash, extractable matter and content of total polyphenols of the root of R. majalis and R. canina do not have significant differences, that is why the root of both plant species can be used as medicinal plant raw materials such as “Rose root”. The obtained data will be used in further research when creating methods of quality control of plant raw materials and phytomedicines

scholarly journals Evaluation of Inhomogeneous Resistive Layers by a Four Point Method

1981 ◽  
Vol 7 (4) ◽  
pp. 211-216
Author(s):  
György Fodor ◽  
Miklós Szilágyi ◽  
László Zombory
Keyword(s):  
Sheet Resistance ◽  
Point Method ◽  
Narrow Strip ◽  
Resistive Layer

This paper describes the determination of the sheet resistance of a narrow strip located in a homogeneous resistive layer of different resistivity. The application of the method for the evaluation of inhomogeneous layers used for thermoprinter head production is discussed.

Rapid determination of binding parameters of chitin binding domains using chitin-coated quartz crystal microbalance sensor chips

The Analyst ◽  
2018 ◽  
Vol 143 (21) ◽  
pp. 5255-5263 ◽  
Author(s):  
Stephan Vogt ◽  
Marco Kelkenberg ◽  
Tanja Nöll ◽  
Benedikt Steinhoff ◽  
Holger Schönherr ◽  
...  
Keyword(s):  
Cell Walls ◽  
Quartz Crystal ◽  
Fungal Infections ◽  
Rapid Determination ◽  
Binding Parameters ◽  
Fungal Cell ◽  
Binding Domains ◽  
Quartz Crystal Microbalance Sensor ◽  
Fungal Cell Walls

Chitin present in fungal cell walls has been considered as a diagnostic polymer for the detection of fungal infections.

Determination of transport constants of isolated Nitella cell walls

1968 ◽  
Vol 46 (4) ◽  
pp. 317-327 ◽  
Author(s):  
M. T. Tyree
Keyword(s):  
Activation Energy ◽  
Cell Wall ◽  
Diffusion Coefficient ◽  
Cell Walls ◽  
Transport Coefficients ◽  
Irreversible Thermodynamics ◽  
Kcal Mole ◽  
Limiting Value ◽  
Nitella Flexilis

Transport coefficients LPP, LPE, LEP, and LEE for electrokinetic equations according to irreversible thermodynamics, the Onsager coefficients, were measured for isolated Nitella flexilis cell walls in KCl solutions ranging from 10−4 to 100 normal. LPP and LPE (= LEP) were found to be independent of KCl concentration and equal to 1.4 × 10−6 cm3 sec−1 cm−2 (joule cm−3)−1 cm and 6 × 10−5 cm3 sec−1 cm−2 volt−1 cm respectively. LEE was a function of the salt concentration, reaching a limiting value of about 1.2 × 10−3 mho cm−1 in 10−4 N KCl. The activation energy for movement of KCl in cell walls was found to be 4.33 Kcal mole−1; the diffusion coefficient for KCl in cell walls was calculated by two methods to be 8 × 10−6 cm2 sec−1; and the concentration of the fixed ions in Nitella cell walls from the above data was estimated at greater than 0.04 equivalent per liter of cell wall. Electroosmosis in Nitella membranes is re-examined in the light of the measured transport coefficients and it is concluded that under proper conditions the cell wall of Nitella can contribute significantly (~20% or more) to the observed electroosmosis of living Nitella cells.

Determination of phenolic acids in plant cell walls by microwave digestion

1994 ◽  
Vol 64 (1) ◽  
pp. 63-65 ◽  
Author(s):  
Gordon J Provan ◽  
Lorraine Scobbie ◽  
Andrew Chesson
Keyword(s):  
Plant Cell ◽  
Phenolic Acids ◽  
Cell Walls ◽  
Microwave Digestion ◽  
Plant Cell Walls
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