ORIGINAL_ARTICLE
A NEW METHOD FOR THE QUANTIFICATION
OF 1 -(MALONYLAMINO)CYCLOPROPANE- 1 -
CARBOXYLIC ACID IN WATER-STRESSED
PLANT TISSUES
Since the discovery of MACC as a major metabolite of both endogenous and
exogenously applied ACC, it has become evident that the formation of MACC from
ACC can act to regulate ethylene production in certain tissues. Hence, it was
suggested that MACC could serve as an indicator of water-stress history in plant
tissues. The accurate quantification of MACC in plant tissues is essential for the
understanding of the role of MACC in the regulation of ethylene biosynthesis.
Hoffman and co-workers described a method for the measurement of MACC in
which it was hydrolysed by HC1 to ACC, which was then assayed by chemical
oxidation to form ethylene. To date, no other method has been developed for
quantifying MACC. Attempts have been made by others to raise monoclonal
antibodies to MACC so that an irnrnunoassay could be developed in order to gain a
deeper understanding of stress-induced ethylene production. However, to date, no
further publications have been forthcoming. Here, quantification methods for MACC
, employing GC-MS are described. This method is compared with widely-used
indirect assay for MACC, which is based upon hydrolysis of MACC to ACC and
conversion of ACC by hypochlorite reagent to ethylene which is subsequently
quantified by gas chromatography
https://jsciences.ut.ac.ir/article_31307_f70e6afb3bc2378ef63c87ffe425b968.pdf
1999-12-01
ORIGINAL_ARTICLE
COBALT PHTHALOCYANINE MODIFIED
CARBON PASTE ELECTRODE AS A
POTENTIOMETRIC SENSOR FOR
DETERMINATION OF ASCORBIC ACID
A carbon Paste electrode modified with cobalt (II) phthalocyanine (CoPC) was
used as a sensitive potentiometric sensor for determination of ascorbic acid in
aqueous solutions. The potential response of the electrode is a linear function of
ascorbic acid concentration over the range 5 10 to 10 M (?1- 1800 µg ML ) with a Nernstian slope of 56 mV at pH 7. The limit of detection was 0.2 µg ml ascorbic acid. The modified electrode was used to determine ascorbic acid in vitamin
preparations. The recovery was 97-98% for the vitamin added to the preparations with
a relative standard deviation of less than 5%.
https://jsciences.ut.ac.ir/article_31308_1e8d8e6507c5fba634d254648e5b3a72.pdf
1999-12-01
ORIGINAL_ARTICLE
COMPARATIVE STUDIES OF
SOLVATOCHROMISM BEHAVIOUR OF
COPPER(I1) AND NICKEL(I1) SCHIFF BASE
COMPLEXES
A series of Schiff Bases of Ni(II) and Cu(II) using acetylacetone (acac),
salicylaldehyde (sal), ethylenediamine (en), and o-phenylendiarnine (dabe) were
prepared and characterized. The electronic spectra of some copper chelates in various
organic solvents depend strongly on the solvent used and the d-d band of Cu(II) shifts
to red with the increase of the Donor Number (DN) of solvent. The color changes from
blue to green are observed. The mechanism for solvatochromism is discussed in terms
of conformational changes and solvent coordination. Among the nickel complexes,
Ni (saloph) is brownish red in chloroform and green in pyridine, probably due to the
coordination of two pyridine molecules
https://jsciences.ut.ac.ir/article_31309_2538d141a69a158645d94157d0eecd23.pdf
1999-12-01
ORIGINAL_ARTICLE
ALKALOIDS OF PAPAVERACEAE (XIX)[l].
ALKALOIDS OF GLA UCIUM PA UCILOB UM
POPULATION GOLESTANFO REST
The Glauciumpaucilobum Freyn population of the Golestan forest contained three
major alkaloids; protopine (0.5%), ?-allocryptopine (0.2%), corydine (0.1 %), and six
minor alkaloids; N-rnethyllind carpine (0.006), bulboca 'nine (0.04%), 4-hydroxy
bulbocapnine (0.001%), Ismorycline (0.04%), arosine (0%02%) and corydine-?-Noxide (0.003%). N-methyllindcrapine, 4-hydroxybulbocapnine and corydine-?-Noxide were detected for the first time in Glaucium paucilobum Freyn. The
stereochemistry at the N-oxide center wasdetermined by was difference measurehent
https://jsciences.ut.ac.ir/article_31310_bcf1d4f72e07e09263df1ae1edb3887a.pdf
1999-12-01
ORIGINAL_ARTICLE
CALCULATION OF OSMOTIC PRESSURE USING
A CLOSED SYSTEM MODEL
In this work we have used a closed system model to derive an analytical equation
for the osmotic pressure of two component electrolyte and non-electrolyte solutions.
In order to do so, we have used an equation of state, known as the dense system
equation of state (DSEOS), for the model system. Based on the model, a new
definition is given for the osmotic pressure of a closed system. Good agreement
between the calculated and experimental osmotic pressure is obtained. Using the
results obtained for the osmotic pressure along with some exact thermodynamic
arguments, we have calculated the solvent activity for some electrolyte and nonelectrolyte
solutions. The calculated activities are found to be in good agreement with
the experiment, in such a way that for the NaCl solutions the deviations for the
calculated activities are less than 0.02% for solutions up to six molal
https://jsciences.ut.ac.ir/article_31311_8803f8c2cca315e4d52fafe6b1955043.pdf
1999-12-01
ORIGINAL_ARTICLE
ELECTRON PARAMAGNETIC RESONANCE
(EPR) SPECTROSCOPY AND GEOCHEMISTRY IN
TIN EXPLORATION AT RENISON, TASMANIA
AUSTRALIA
Rock powder of dolomite samples from the Renison mine area of Tasmania,
Australia were analyzed by electron paramagnentic resonance spectroscopy (EPR),
Atomic Absorption and Mass Spectrometer to identify alteration related to
mineralisation. The least-altered dolomite samples, which are not effected by circulation
of diagenetic and hydrothermal fluids are characterised by low Mn and Fe and heavier
oxygen isotope values. In contrast, the altered samples are characterised by high Fe
and Mn and light oxygen isotope values. Significant differences in EPR intensity exist
between the unaltered and altered dolomite samples. The highly altered samples close
to the nlineralised area are characterised by strong EPR intensities of Mn sextets
observed at magnetic flux density sweeps over 326.3 2500 mT and 326.3 1000
mT, which correspond to the higher Mn and Fe and lighter oxygen isotope values. In
contrast, in the least-altered dolomites, away from the mineralised area, the EPR
intensity and Mn and Fe concentrations are low and oxygen isotope values are more
enriched
https://jsciences.ut.ac.ir/article_31312_a64bffcb5d8ecedc4968396d9df73b97.pdf
1999-12-01
ORIGINAL_ARTICLE
THE EXISTENCE AND UNIQUENESS OF THE
SOLUTION OF THE SPECTRAL PROBLEM II
FOLLOING OUR PREVIOS PROJECT [1], WE ARE GOING TO PROVE THE EXISTENCE AND UNIQUENESS OF THE SOLUTION OF THE SPECTRAL PROBLEM IN THIS PROJECT.FIRST,WE HAVE PROVEN THE UNIQUENESS OF THE SOLUTION THEN TO PROVE THE EXISTRNCE WE CONSTENSS OF THE ADJOINT PROBLEM CORRESPONDING TO THIS SPECTRAL PROBLEM NEXT THE UNIQUESS OF THE ADJOINT PROBLEM IS THE EXISTENCE OF THE MAIN PROBLEM AS DISCUSSED BY[2] AND [3] WE HAVE DETERMINED THE EXISTENCE OF THE SPECTRAL PROBLEM THE PAPER WILL CONCLUDE WITH THREE UNISOLVED PROBLEMS
https://jsciences.ut.ac.ir/article_31313_c59ed3b4cd144868e64322eb98646c7c.pdf
1999-12-01
ORIGINAL_ARTICLE
A FILTERED B-SPLINE MODEL OF SCANNED
DIGITAL IMAGES
We present an approach for modeling and filtering digitally scanned images. The
digital contour of an image is segmented to identify the linear segments, the nonlinear segments and critical corners. The nonlinear segments are modeled by B-splines. To remove the contour noise, we propose a weighted least q m s model to account for both the fitness of the splines as well as their approximate curvatures. The solutions of the least squares models provide the control vertices of the splines. We show the effectiveness of our approach with several representations constructed from various scanned images
https://jsciences.ut.ac.ir/article_31314_529eba2742cae92f1b11774540aa811f.pdf
1999-12-01
ORIGINAL_ARTICLE
ESTIMATION OF SCALE PARAMETER UNDER A
REFLECTED GAMMA LOSS FUNCTION
In this paper, the estimation of a scale parameter t under a new and bounded loss
function, based on a reflection of the gamma density function, is discussed. The best
scale-invariant estimator of tis obtained and the admissibility of all linear functions
of the sufficient statistic, for estimating t in the absence of a nuisance parameter, is
investigated
https://jsciences.ut.ac.ir/article_31315_ed4fdcc02626ac6d200a6265856bbb22.pdf
1999-12-01
ORIGINAL_ARTICLE
THE ROLE OF QUARK POLARIZATION IN
HEAVY QUARK FRAGMENTATION
We calculate the exact fragmentation functions for c and b quark fragmentation
taking into account the spin orientation of the initial heavy quark in the form of
analytical and rather simple expressions. Our calculations show that spin orientation
may have an important effect on the fragmentation spectrum. This effect is more
striking in the cases of c ?D, D*; c? ? , ? , and ?B , B *.
https://jsciences.ut.ac.ir/article_31316_0f32a00b58f3d8db5c637346fd2645f6.pdf
1999-12-01