Adaptive Interpolation by Scaled Multiquadrics

We present an adaptive method to extract shape-preserving information from a univariate data sample. The behavior of the signal is obtained by interpolating at adaptively selected few data points by a linear combination of multiquadrics with variable scaling parameters. On the theoretical side, we give a sufficient condition for existence of the scaled multiquadric interpolant. On the practical side, we give various examples to show the applicability of the method.     

Synthesis of α-amino γ-butyrolactone derivatives by aziridination of α-ylidene γ-butyrolactones

The reactions of exocyclic α,β-unsaturated γ-lactones with NsONHCO₂Et and CaO produce N-(ethoxycarbonyl) spiroaziridino γ-lactones. By reaction with acetic acid these products give ring opening reaction and acetylated N-protected α-amino γ-butyrolactones are obtained. The ring opening reaction is quantitative and highly regioselective.     

Electric parameters of photosystem II particles — electric light scattering study

Electric light scattering and microelectrophoresis were applied to investigate the electric moments (permanent dipole moment and electric polarizability and electrophoretic mobility of envelope-free chloroplasts and photosystem II (PS II particles. The effect of the removal of the extrinsic polypeptides (18, 24 and 33 kDa) on the electric moments was also studied. A significant difference was observed between the orientation behaviour of chloroplasts and PS II preparations. The data indicate that the permanent and induced dipole moments contribute to the orientation of the PS II particles, whereas chloroplasts possess induced dipole moment only.

NaCl and Tris treatments of PS II preparations influence both the transverse permanent dipole moment and the electric polarizability of PS II particles. The increase in the electrophoretic mobility of PS II particles on removal of the extrinsic proteins corresponds to an increase in the electric polarizability value, demonstrating its interfacial nature.     

Kinetic nature of the thermal destabilization of LHCII macroaggregates

The main light-harvesting chl a/b pigment-protein complex of photosystem II (LHCII) in isolated state forms macroaggregates with different ultrastructure and lipid content [I. Simidjiev, V. Barzda, L. Mustardy, G. Garab, Anal. Biochem. 250 (1997) 169-175]. The thermodynamic stability of highly delipidated tightly bound LHCII macroaggregates is studied by differential scanning calorimetry and fluorescence spectroscopy. The calorimetric profile of LHCII is asymmetric, the denaturation transition is taking place at around 72 degrees C. A shoulder, which overlaps with the main denaturation transition, appears around 58 degrees C. The denaturation temperature strongly depends on the scanning rate indicating the kinetic nature of the thermal destabilization of LHCII macroaggregates. The fluorescence data prove that the thermal denaturation of LHCII is an irreversible and kinetically controlled process.     

The effect of implementation of the ISO 9000 on customer complaints; a 5-year follow-up study in a regional laboratory.

Although the importance of quality management in the medical laboratory has been emphasized, we are unaware of any interventional studies demonstrating benefits of implementation of recommendations of the International Standards Organization (ISO). In the following 5-year follow-up study, we implemented quality management as stipulated by the ISO, received a certificate of approval, and determined how the program affected customer complaints. From 1997 to 2001 there was only a slight decrease in the number of customer complaints, but a significant continuing downward trend in the proportion of justified complaints (chi-squared test, p<0.001). In fact in 2001 the proportion of justified complaints had decreased by nearly 80% (relative risk, 0.22; 95% confidence interval, 0.09–0.52)), to only 10.9% of the total complaints. We conclude that the use of the ISO 9000 along with good laboratory practice resulted in a significant decrease in the proportion of justified complaints.     

Size-based analysis of incinerator fly ash using gravitational SPLITT fractionation, sedimentation field-flow fractionation, and inductively coupled plasma-atomic emission spectroscopy

Fly ash has been regarded as hazardous because of its high adsorption of toxic organic and/or inorganic pollutants. Fly ash is also known to have broad distributions of different chemical and physical properties, such as size and density. In this study, fly ash emitted from a solid waste incinerator was pre-fractionated into six sub-populations by use of gravitational SPLITT fractionation (GSF). The GSF fractions were then analyzed by sedimentation field-flow fractionation (SdFFF) and ICP–AES. SdFFF analysis showed the fly ash has a broad size distribution ranging from a few nanometers up to about 50 µm. SdFFF results were confirmed by electron microscopy. Inductively coupled plasma–atomic emission spectroscopy (ICP–AES) analysis of the GSF fractions showed the fly-ash particles contain a variety of inorganic elements including Ca, Si, Mg, Fe, and Pb. The most abundant in fly ash was Ca, followed by Si then Mg. No correlations were found between trace element concentration and particle size.     

Addition reactions of ethoxycarbonylnitrene and ethoxycarbonylnitrenium ion to allylic ethers

Ethoxycarbonylnitrene (EtOCON) generated by α-elimination adds cleanly to allylic ethers giving substituted aziridines. Similar addition via nitrenium ion (EtOCONH⁺) gives derivatives of β-amino alcohols.     

Kinetic determination of trace levels of selenium(IV) and total selenium by Nile Blue A/hydrogen peroxide method

A kinetic method for the determination of selenium(IV) traces is proposed, based on its inhibitory action on the oxidation of Nile Blue A by hydrogen peroxide in phosphate buffer (pH 10.5). A linear dependence was established between the rate of the proposed indicator reaction and selenium concentration in the range 9.5 × 10^–2-1.58 ng cm^–3. The experimental conditions of maximal selenium effect were established. Selenium, determined by the tangent method, was determined at concentrations over the range 0.22–1.26 ng cm^–3, with relative standard deviations up to 4.5%. The reaction rate was followed spectrophotometrically. The effect of foreign ions on the accuracy of this method was also investigated. The method was applied to the determination of selenium in pharmaceutical preparations and wheat flour.     

Synthesis of β,β-branched β-amino ester derivatives through spiroaziridination of (α-trimethylsilanylmethyl)cyclohexylidene esters

The reaction of (α-trimethylsilanylmethyl)cyclohexylidene esters with NsONHCO₂Et and CaO produces the N-(ethoxycarbonyl)spiroaziridines which, after ring-opening, gives the corresponding β,β-disubstituted β-amino ester derivatives. The stereochemical outcome of the reaction is influenced by substituents on the cyclohexyl group.