Patterning molecularly thin films of polymers—new methods for photolithographic structuring of surfaces

Three novel photolithographic processes for patterning of molecularly thin polymer films are described. The polymer monolayers are prepared by immobilization of initiator molecules to surfaces of solid substrates followed by thermally or photochemically activated radical chain polymerization. Thus polymer chains which are covalently linked to the surfaces of the substrates are obtained. The films can be patterned using appropriate masks and deep or near UV irradiation before, during or after polymer formation. The procedures described in this paper allow the chemical tailoring of surfaces with high spatial resolution. Step-and-repeat procedures, which take advantage of the covalent linking of the polymers to the surfaces, permit the preparation of multifunctional polymer patterns.     

The 2nd international conference on phase transfer catalysis “phase-transfer catalysis — new ideas and methods”

Information Congresses, Conferences, Symposia, Meetings, and Seminars held with the Participation of the Russian Academy of Sciences

The 2nd international conference on phase transfer catalysis phase-transfer catalysis — new ideas and methods     

A new methodology for the development of numerical methods for the numerical solution of the Schr?dinger equation

In the present paper we introduce a new methodology for the construction of numerical methods for the approximate solution of the one-dimensional Schr?dinger equation. The new methodology is based on the requirement of vanishing the phase-lag and its derivatives. The efficiency of the new methodology is proved via error analysis and numerical applications.     

A new algorithm of two-electron repulsion integral calculations: a combination of Pople–Hehre and McMurchie–Davidson methods

A new algorithm of two-electron repulsion integral (ERI) calculations has been developed. In this algorithm, Cartesian axes are rotated to make several coordinate components zero or constant using the Pople–Hehre algorithm, and ERIs are evaluated at the rotated coordinate by the McMurchie–Davidson algorithm. The new algorithm applicable to (ss|ss) to (dd|dd) ERIs is implemented in the quantum chemistry program GAMESS. Test calculations show that the new algorithm reduces the computational times by 10–40%, as compared with the Pople–Hehre and the Rys quadrature algorithms.     

“COMPLEX” Reduction of multimetal iron and nickel ores as a basis for new methods for their chemical treatment

Russian Chemical Bulletin -     

BEDT–TTF charge-transfer salts: new structures,new functionalities

In the continuing search for new physical properties and combinations of properties in molecular materials, novel phenomena and structures are identified in three categories of TTF and BEDT–TTF (bis-ethylenedithiotetrathiafulvalene) charge-transfer salts with inorganic complex anions. When the anion is a 3d complex containing NCS^– and an aromatic donor, long range π–d ferrimagnetic order is established by donor-anion π–π overlap; when the anion is a tris-oxalato-metallate(III) complex, both normal state and superconducting behaviour are dramatically influenced by changing guest molecules in the lattice, while incorporating columns of crown ether and H₃O⁺/H₂O leads to metallic conductors that simultaneously transport protons. To cite this article: P. Day, C. R. Chimie 6 (2003).     

A new family of two stage symmetric two-step methods with vanished phase-lag and its derivatives for the numerical integration of the Schrödinger equation

A family of two stage low computational cost symmetric two-step methods with vanished phase-lag and its derivatives is developed in this paper. More specifically we produce:

• a two-stage symmetric two-step eighth algebraic order method which has the phase-lag and its first, second and third derivatives vanished and
• a two-stage symmetric two-step sixth algebraic order method, which is P-stable and has the phase-lag and its first and second derivatives vanished.

The local truncation error, the interval of periodicity and the effect of the vanishing of the phase-lag and its derivatives on the efficiency of the obtained method are also studied in this paper.

     

Microfluidic methods for cell separation and subsequent analysis

Cell is the most basic unit of the morphological structure and life activity of an organism. Learning the composition, structure and function of cells, exploring the life activities of cells and studying the interaction between cells are of great significance for human cognition and control of the life activities of organisms. Therefore, rapid, convenient, inexpensive, high-precision and reliable methods of cell separation and analysis are being developed to obtain accurate information for the s...     

New spectroscopic methods for environmental measurement and monitoring

The ability to monitor a broad range of chemical species in the atmosphere, geosphere, and hydrosphere is a key technology for addressing global environmental issues. This report surveys several high sensitivity spectroscopic techniques for this purpose, including Frequency-Modulation-Enhanced Remote Sensing, In-traCavity Laser Absorption Spectroscopy, Cavity RingDown Spectroscopy, and Raman Spectroscopy.     

Rifamycin antibiotics—new compounds and synthetic methods. Part 3: Study of the reaction of 3-formylrifamycin SV with primary amines and ketones

In the third stage of our study concerning the search for new antibacterial rifamycin antibiotics, the reactions of 3-formylrifamycin SV (1) with a range of primary alkylamines and ketones of general structure R₁–CH₂–CO–R₂ (R₁H or alkyl and R₂alkyl or aryl) has been investigated. A new synthetic method for the preparation of a new group of rifamycin derivatives with an α,β-unsaturated imine substituent at C-3 has been developed.These compounds showed a tendency to reversibly isomerise in organic solvents and, in the presence of water, to rapidly hydrolyse. The structures of four isolated microcrystalline compounds 2, 3, 4, 5 and a reaction's mechanism have been proposed on the basis of mass spectrometry results as well as (1D) and (2D) ¹H and ¹³C NMR analysis. The new synthetic route reported herein is a promising pathway to new reactive rifamycins displaying broader capabilities than the plain 3-formylrifamycin SV.     

Can the usual validation standard series for quantitative methods,ISO 5725, be also applied for qualitative methods?

Repeatability standard deviation, laboratory standard deviation, and reproducibility standard deviation for quantitative methods according to ISO 5725 series were recently proposed to estimate the precision of qualitative measurements, giving a presence/absence response. In this paper, it is shown that for qualitative methods, the reproducibility standard deviation across laboratories does not reflect the performance of the method as suggested. It is demonstrated that the benefit of the respective laboratory standard deviation is very limited. Alternative performance measures are introduced which are based on another approach also directly linked to ISO 5725. Thereby, meaningful information about the precision of qualitative test methods can be achieved.     

Silicone surfactants—new developments

Silicone surfactants—copolymers of silicone and polyethers—are useful for applications in which their high surface activity and silicone character provide performance advantages. They have recently been shown to enhance the efficiency of microemulsions. Systematic studies of their phase behavior continues to expand our knowledge of the self-assembly of large molecules. They are beginning to be used to prepare nanostructured materials. The unusual wetting properties of the trisiloxane surfactants has been much discussed, leading to a better understanding of the roles of diffusion, surfactant aggregation, and Marangoni effects in surfactant enhanced spreading.     

Nanobioanalytical luminescence: Förster-type energy transfer methods

Förster resonance energy transfer-based analytical techniques represent a unique tool for bioanalysis because they allow one to detect protein–protein interactions and conformational changes of biomolecules at the nanometer scale, both “in vitro” and “in vivo” in cells, tissues and organisms. These techniques are applied in diverse fields, from the detection and quantification of ligands able to bind to proteins or receptors to the development of RET-based whole-cell biosensors, microscope imaging techniques and “in vivo” whole-body imaging for the monitoring of physiological and pathological processes. However, their quantitative performances need further improvements and, even though RET measurement principles and procedures have been continuously improved, in some cases only qualitative or semiquantitative information can be obtained. In this review we report recent applications of RET-based analytical techniques and discuss their advantages and limitations.

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Figure RET-based techniques allow analysis of protein–protein interactions and conformational changes of biomolecules at the nanometer scale

     

A new embedded 5(3) pair of modified Runge–Kutta–Nyström methods for the numerical solution of the Schrödinger equation

A new embedded 5(3) pair of modified Runge–Kutta–Nyström methods for the numerical solution of the Schrödinger equation is developed in this paper. The asymptotic expressions of the principal local truncation errors for large energies are obtained. We apply the new fifth-order method to the resonance problem, and apply the new embedded 5(3) pair to elastic scattering phase-shift problem. The numerical results show good numerical performance of the new embedded pair and the fifth-order method.     

Analysis of pure copper – a comparison of analytical methods

The reliability and performance of various analytical methods for the determination of 22 trace elements in pure copper is compared and discussed. The work was performed in the framework of an interlaboratory comparison for the preparation of four pure copper reference materials with graded element mass fractions of Ag, Al, As, Bi, Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, Zn, and Zr. Special analytical results (ET-AAS, ICP-MS) obtained by the authors were described in more detail and were compared to the certified values. Special regard was paid to the influence of the copper matrix on performance and sensitivity of each analytical method and to the dissolution procedure of copper matrix and interferences from insoluble residues. For a generalized evaluation of the figures of merit for each applied elemental analytical method results from several independent laboratories were included in the discussion. Correspondence: Britta Lange, Department of Analytical Chemistry, Reference Materials, Federal Institute for Materials Research and Testing (BAM), Richard-Willstaetter-Str. 11, D-12489 Berlin, Germany     

How accurate are electronic structure methods for actinoid chemistry?

The CASPT2, CCSD, and CCSD(T) levels of wave function theory and seven density functionals were tested against experiment for predicting the ionization potentials and bond dissociation energies of actinoid monoxides and dioxides with their cations. The goal is to guide future work by enabling the choice of an appropriate method when performing calculations on actinoid-containing systems. We found that four density functionals, namely MPW3LYP, B3LYP, M05, and M06, and three levels of wave function theory, namely CASPT2, CCSD, and CCSD(T), give similar mean unsigned errors for actinoid?Coxygen bond energies and for ionization potentials of actinoid oxides and their cations.     

Confidence in testing services – new expectations, new rules, new challenges. 5th Eurolab Symposium offered important information and stimulating discussions

The 5th Eurolab Symposium on 4th and 5th October in Edinburgh was the highlight event of Eurolab in 2000, Eurolab’s 10th anniversary year. Under the title: ”Confidence in Testing Services – new expectations, new rules, new challenges” it reflected recent changes and developments in the laboratory scene and focussed on new tasks and challenges. The most essential changes for laboratories are connected with the new standard ISO/IEC 17025 ”General requirements for the competence of testing and calibration laboratories”. Keywords in this respect are uncertainty of measurement and traceability to SI units, requirements on personnel, proficiency testing, customer orientation, and management systems.