Abscisic acid (ABA) was purified from soybean (Glycine max [L.]) seed extract using a preparative high performance liquid chromatography (HPLC) procedure. The preparative procedure was rapid (70 minutes per sample), required no prior partitioning for purification and was quantitative as demonstrated with an internal standard of [2-(14)C]ABA, of which 98.9% was recovered.Following purification b...

The stationary and highly non-stationary resonant dynamics of the harmonically forced pendulum are described in the framework of a semi-inverse procedure combined with the Limiting Phase Trajectory concept. This procedure, implying only existence of slow time scale, permits to avoid any restriction on the oscillation amplitudes. The main results relating to the dynamical bifurcation thresholds ...

In this paper, we extend previous work on geographic random forwarding (GeRaF) by considering a more efficient paradigm whereby on/off cycles are exploited and every node can participate to packet relaying, as long as it wakes up during any handshake procedure. The protocol is fully distributed, as routing decisions are made hop by hop based on geographic metrics and using a joint channel acces...

We describe a "high-performance" liquid-chromatographic procedure for measuring 3-methoxy-4-hydroxymandelic acid (vanillylmandelic acid) in urine. The compound is quantitatively extracted from urine by use of an automated system, including an anion-exchange resin. After elution from the resin and concentration by air drying, the urine extract is chromatographed on an octyl silica column, with u...

In general, one cannot use algebraic or enumerative methods to optimize a quality-control (QC) procedure for detecting the total allowable analytical error with a stated probability with the minimum probability for false rejection. Genetic algorithms (GAs) offer an alternative, as they do not require knowledge of the objective function to be optimized and can search through large parameter spac...

The aim of this study was to evaluate two important aspects of patent applications of crystalline forms of drugs: (i) the physicochemical characterization of the crystalline forms; and (ii) the procedure for preparing crystals of the blockbuster drug clopidogrel. To this end, searches were conducted using online patent databases. The results showed that: (i) the majority of patent applications ...

This work describes an analytical procedure for vanadium determination in human hair slurries by electrothermal AAS using longitudinal heating (LHGA) and transversal heating (THGA) graphite furnace atomizers. The samples were powdered using cryogenic grinding and the hair slurries containing 0.2% (m/v) were prepared in three different media for determination of vanadium: 0.14molL(-1) HNO(3), 0....

A method for finding of the solutions of the state equations of descriptor fractional discrete-time linear systems with regular pencils and a procedure for computation of transition matrices of the system are proposed. On the basis of this procedure a computer algorithm which calculates the transition matrices and solution of the system is presented. The effectiveness of the proposed procedure ...

The procedure for experimental-analytical prediction of flexural strength is reviewed. It allows consideration of size effect phenomena with only minor modification of standard laboratory test procedure. Two possibilities are suggested: testing with one size only and testing with two sizes. The application of this procedure to real case, a massive concrete subway tunnel constructed recently in ...

A two-step procedure is described in which analytical disc gel electrophoresis in polyacrylamide is used to demonstrate oligoclonal bands of immunoglobulin G in cerebrospinal fluid. The principal advantage of the procedure is that unconcentrated samples of cerebrospinal fluid as small as 200 fiL can be assayed. The results obtained in samples from 100 patients with various neurologic diseases s...