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Short Overview (short + overview)
Selected AbstractsSleep-related memory consolidation in depression: an emerging field of researchDEPRESSION AND ANXIETY, Issue 12 2008Orla Patricia Hornung Ph.D. Abstract Sleep-related memory consolidation has received increasing attention in recent years. Because previous research has focused on healthy young adults, only very few studies have been conducted in patients with psychiatric disorders so far. The investigation of sleep-related memory consolidation in depression offers a wide range of future research opportunities and can therefore be regarded as an emerging field of research. This article gives a short overview of current knowledge of sleep-related memory consolidation in healthy young adults and builds a bridge to psychiatry and depression, where further research is urgently needed. Depression and Anxiety, 2008. © 2007 Wiley-Liss, Inc. [source] Separation of enantiomers with charged chiral selectors in CEELECTROPHORESIS, Issue S1 2009Bezhan Chankvetadze Abstract In this short overview the major developments in separation of enantiomers with charged chiral selectors are summarized in CE. The advantages of charged chiral selectors in comparison with their uncharged analogues are emphasized from the viewpoints of higher flexibility, higher and alternative separation selectivity, as well as alternative chiral recognition mechanism. [source] Derivatization of inorganic ions in capillary electrophoresisELECTROPHORESIS, Issue 12-13 2003Audrius PadarauskasArticle first published online: 8 JUL 200 Abstract This review gives a short overview of the main approaches to the derivatization of inorganic ions in capillary electrophoresis (CE) with emphasis on the most recent works. Various derivatization procedures and detection methods are discussed. A brief account of their advantages and limitations is given. More specific areas such as microchip CE, simultaneous separation of anions and cations, and speciation analysis are also briefly discussed. [source] Data analysis of environmental air pollutant monitoring systems in EuropeENVIRONMETRICS, Issue 6 2004Kristina Voigt Abstract Public access to information about the environment is being strengthened across Europe. The concept of public's right to information gives the basis for the access to environmental information. In this paper the quality of air pollutant monitoring systems in the 15 European member states is analyzed. For pragmatic reasons only the capitals are looked upon. Comprehensive data on environmental monitoring programs concerning air pollutants like ozone (O3), nitrogen dioxide (NO2), nitrogen oxide (NO), carbon dioxide (CO2) and carbon monoxide (CO), and sometimes suspended dust, benzene and other environmental chemicals are available on the free Internet. As different monitoring information systems exist in the European member states a comparison of these systems with their pros and cons is of great interest to the public. Environmental air pollutant monitoring systems in the capitals of the 15 EEC member countries (objects) are evaluated by applying 5 evaluation criteria for the differentiation of these systems. The scores run from 0,=,insufficient, 1,=,medium, to 2,=,excellent. Different data-analysis methods will be applied. As order theory is still not sufficiently presented in the scientific literature, a short overview about the so-called Hasse diagram technique and POSAC method is outlined. In several steps the data-matrix is analyzed coming to the conclusion that all methods (additionally PCA is used) identify one criterion as specifically important. Not unexpected, each method has its own advantage. The aim of this data-analysis is the evaluation of the publicly available air quality monitoring systems in Europe with their pros and cons. This might help the interested public to find and understand the information given on the Internet. Furthermore our evaluation approach might give some recommendations for an improvement of the air quality monitoring systems. Copyright © 2004 John Wiley & Sons, Ltd. [source] Erythropoiesis and red cell function in vertebrate embryosEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2005R. Baumann Abstract All vertebrate embryos produce a specific erythroid cell population , primitive erythrocytes , early in development. These cells are characterized by expression of the specific embryonic haemoglobins. Many aspects of primitive erythropoiesis and the physiological function of primitive red cells are still enigmatic. Nevertheless, recent years have seen intensive efforts to characterize in greater detail the molecular events underlying the initiation of erythropoiesis in vertebrate embryos. Several key genes have been identified that are necessary for primitive and the subsequent definitive erythropoiesis, which differs in several aspect from primitive erythropoiesis. This review gives in its first part a short overview dealing with comparative aspects of primitive and early definitive erythropoiesis in higher and lower vertebrates and in the second part we discuss the physiological function of primitive red cells based mainly on results from mammalian and avian embryos. [source] Enthalpy/Entropy Compensation in the Melting of Thermotropic Nitrogen-Containing Chelating Ligands and Their Lanthanide Complexes: Successes and Failures,,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2010Aude Escande Abstract In this short overview dedicated to the thermodynamics of liquid crystalline chelating nitrogen-containing ligands and their lanthanide complexes (i.e., lanthanidomesogens), we first go through the initial successes obtained with the introduction of the concept of enthalpy/entropy compensation for rationalizing and programming melting and clearing temperatures in thermotropic mesophases. In the second part, the failures encountered during our attempts for switching from a qualitative toward a quantitative interpretation of the melting processes in polycatenar lanthanidomesogens are discussed, together with the delicate correlations established between the thermodynamic parameters of intermolecular cohesion measured in noncoordinating solvents and those operating in pure mesophases. [source] Computational Methods for the Development of Polymeric BiomaterialsADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Aurora D. Costache This review focuses on polymeric biomaterials and provides a selective overview of the computational modeling approaches used to predict their properties and biological responses. Also, a short overview of existing databases and software packages for the biomaterials field is presented. The review summarizes the research in this area since the year 2000. [source] Metal/Ceramic Interface Properties and Their Effects on SOFC DevelopmentFUEL CELLS, Issue 6 2009F. Tietz Abstract Development of solid oxide fuel cells (SOFCs) involves multidisciplinary research, which needs input from many directions. As an example, this contribution describes the influence of basic metallurgical experiments on the selection or the modification of specific materials used in SOFCs. Wettability studies, although typically regarded as model experiments, give clear indications of the combinations of materials, which show better compatibility and might be more successfully integrated in SOFC designs, especially when metal/ceramic interfaces are involved. Various material combinations, i.e. anode cermets, glass/steel and ceramic/silver/steel compounds, are discussed in more detail showing the impact of fundamental studies on the SOFC development actually applied. This work gives a short overview on the basic aspects of selected material combinations. [source] Regional Climate Models for Hydrological Impact Studies at the Catchment Scale: A Review of Recent Modeling StrategiesGEOGRAPHY COMPASS (ELECTRONIC), Issue 7 2010Claudia Teutschbein This article reviews recent applications of regional climate model (RCM) output for hydrological impact studies. Traditionally, simulations of global climate models (GCMs) have been the basis of impact studies in hydrology. Progress in regional climate modeling has recently made the use of RCM data more attractive, although the application of RCM simulations is challenging due to often considerable biases. The main modeling strategies used in recent studies can be classified into (i) very simple constructed modeling chains with a single RCM (S-RCM approach) and (ii) highly complex and computing-power intensive model systems based on RCM ensembles (E-RCM approach). In the literature many examples for S-RCM can be found, while comprehensive E-RCM studies with consideration of several sources of uncertainties such as different greenhouse gas emission scenarios, GCMs, RCMs and hydrological models are less common. Based on a case study using control-run simulations of fourteen different RCMs for five Swedish catchments, the biases of and the variability between different RCMs are demonstrated. We provide a short overview of possible bias-correction methods and show that inter-RCM variability also has substantial consequences for hydrological impact studies in addition to other sources of uncertainties in the modeling chain. We propose that due to model bias and inter-model variability, the S-RCM approach is not advised and ensembles of RCM simulations (E-RCM) should be used. The application of bias-correction methods is recommended, although one should also be aware that the need for bias corrections adds significantly to uncertainties in modeling climate change impacts. [source] Recent Developments in Synthetic Chemistry, Chiral Separations, and Applications of Tröger's Base AnaloguesHELVETICA CHIMICA ACTA, Issue 3 2009Sergey Sergeyev Abstract Tröger's base is a well-known chiral molecule with a few unusual structural features. The chemistry of Tröger's base analogues has been greatly developed over the last 20 years, and numerous interesting applications in supramolecular chemistry and in molecular recognition have emerged. This Review gives a short overview of the chemistry of Tröger's base and its analogues, with particular focus on recent achievements in synthesis, enantiomer separations, and applications. [source] Numerical simulation of gaseous fuel injection: A new methodology for multi-dimensional modellingINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 6 2010Luca Andreassi Abstract The use of natural gas (instead of liquid or solid fuels) is nowadays drawing an increasing interest in many applications (gas turbines, boilers, internal combustion engines), because of the greater attention to environmental issues. To facilitate the development of these applications, computer models are being developed to simulate gaseous injection, air entrainment and the ensuing combustion. This paper introduces a new method for modelling the injection process of gaseous fuels that aims to hold down grid requirements in order to allow the simulation also of other phenomena, like combustion or valve and piston motion, in reciprocating internal combustion engines. After a short overview of existing models, the transient jet model and the evaluation of inflow conditions are described in detail. Then a basic study of the grid effects on the jet evolution is presented. The model is updated and validated by comparing numerical results with available experimental data for two different operating conditions: a subsonic and a supersonic under-expanded case. The model demonstrates to be fast enough to be used in a multi-dimensional code and accurate enough to follow the real gas jet evolution. Copyright © 2009 John Wiley & Sons, Ltd. [source] Hemoprotein time-resolved X-ray crystallographyIUBMB LIFE, Issue 3 2008Mario Milani Abstract In the last decade the role of structural dynamics in controlling protein function was actively investigated using new and advanced experimental approaches. In particular, time resolved crystallography, despite some practical difficulties, is being used extensively to complement the study of protein structure-function relationships with information on the dynamics, based on experimental evidence. Here we present a short overview of the results obtained on dynamical properties of myoglobin and homologous hemoproteins, where the photosensitive heme-Fe,ligand bond has allowed transient intermediates to be studied by different flash photolysis methods coupled to Laue X-ray diffraction, thus highlighting some of the dynamical events that characterize diffusion of a diatomic ligand to/from the heme in model hemoproteins. © 2008 IUBMB IUBMB Life, 60(3): 154,158, 2008 [source] Could a common biochemical mechanism underlie addictions?JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 1 2000C. Betz The subject of ,drug addiction' is multifaceted and many aspects of it (even some of the definitions) are controversial. Collateral medical problems include the spread of HIV and hepatitis C virus secondary to i.v. drug abuse and effects on prenatal brain development ( 1). Progress in the understanding of the causes of addictions and its treatment has been impeded by the lack of a unifying biochemical theory. However, recent evidence suggests that some common mechanism might underlie addictions to otherwise apparently unrelated drugs. A major hypothesis has emerged suggesting that the neurotransmitter dopamine (DA) might play a central role in the molecular mechanisms of at least some addictions. If so, it would represent an important target for discovery of effective pharmacotherapy and revolutionize the pharmacist's role in treating addictions. This short overview outlines the status of the theory of a common biochemical mechanism of drug addiction. [source] The Heckman Correction for Sample Selection and Its CritiqueJOURNAL OF ECONOMIC SURVEYS, Issue 1 2000Patrick Puhani This paper gives a short overview of Monte Carlo studies on the usefulness of Heckman's (1976, 1979) two-step estimator for estimating selection models. Such models occur frequently in empirical work, especially in microeconometrics when estimating wage equations or consumer expenditures. It is shown that exploratory work to check for collinearity problems is strongly recommended before deciding on which estimator to apply. In the absence of collinearity problems, the full-information maximum likelihood estimator is preferable to the limited-information two-step method of Heckman, although the latter also gives reasonable results. If, however, collinearity problems prevail, subsample OLS (or the Two-Part Model) is the most robust amongst the simple-to-calculate estimators. [source] Raman spectroscopy in art and archaeologyJOURNAL OF RAMAN SPECTROSCOPY, Issue 10 2006Ludovic Bellot-Gurlet Abstract This paper gives a short overview of the Special Issue on Raman Spectroscopy in Art and Archaeology, with the papers collected after the ,3rd International Conference on the Application of Raman Spectroscopy in Art and Archaeology' held at the University Pierre et Marie Curie-Paris 6, Paris, France, from 31 August to 3 September, 2005. The contributions present an extended view of the work in the field, from technical developments and special analytical procedures to various applications. Copyright © 2006 John Wiley & Sons, Ltd. [source] Determination of adsorption isotherms by means of HPLC: Adsorption mechanism elucidation and separation optimizationJOURNAL OF SEPARATION SCIENCE, JSS, Issue 5-6 2009Nicola Marchetti Abstract The purpose of this review is to illustrate the most important techniques for isotherm determination by means of HPLC. Starting on the traditional Frontal Analysis approach, Frontal Analysis by Characteristic Point, Elution by Characteristic Point, Perturbation Method in its different applications will be considered to conclude with the most recent Inverse Method approach. Since many of these techniques are based on the fundamentals of nonlinear chromatography, a short overview of the theory of nonlinear chromatography is presented. Emphasis is given to the most recent applications of these techniques for pharmaceutical applications, characterization of binding mechanisms, bioaffinity studies, molecular and chiral recognition processes. [source] Regulation of cholangiocyte proliferationLIVER INTERNATIONAL, Issue 2 2001Gene LeSage Abstract: Intrahepatic bile duct epithelial cells (i.e., cholangiocytes) are the target cells of chronic cholestatic liver diseases (i.e., cholangiopathies), which makes these cells of great interest to clinical hepatologists. This review will focus on "typical" cholangiocyte proliferation, whereas "atypical" (extension of cholangiocyte proliferation into parenchyma), and premalignant "oval" cell proliferation are reviewed elsewhere. The bile duct ligated (BDL) rat model, where most of the known mechanisms of cholangiocyte proliferation have been illustrated, was the first and remains the prototype animal model for "typical" cholangiocyte proliferation. Following a short overview of cholangiocyte functions, we briefly discuss the: (i) in vivo models [i.e., BDL (Fig. 1 and 4), chronic ,-naphthylisothiocyanate (ANIT) or bile acid feeding (Fig. 2), acute carbon tetrachloride (CCl4) feeding and partial hepatectomy; and (ii) in vitro experimental tools [e.g., purified cholangiocytes and isolated intrahepatic bile duct units (IBDU)] that are key to the understanding of the mechanisms of "typical" cholangiocyte growth. In the second part of the review, we discuss a number of potential factors or conditions [e.g., gastrointestinal hormones, nerves, estrogens, blood supply, and growth factors] as well as the intracellular mechanisms [e.g., adenosine 3,,5,-monophosphate (cAMP), and protein kinase C (PKC)] that may regulate "typical" cholangiocyte hyperplasia. Figure 1. Measurement of the number of intrahepatic bile ducts by histochemistry for ,-GT[a specific cholangiocyte marker (1, 3, 27)] in liver sections from normal rats [left] and rats that (immediately following bile duct ligation (BDL)) were infused by osmotic minipumps with 0.2% bovine serum albumin (BSA, control) [middle] or gastrin (2.5 nmol/kg/h) in 0.2% BSA [right] for 1 week. Following BDL [middle], there was a marked increase in the number of ducts as compared to normal rats [left]. Chronic gastrin infusion [right] markedly decreased the number of intrahepatic bile ducts as compared to BSA-treated BDL rats [middle]. Orig. magn., ×125. Reproduced with permission from reference (17). Figure 4. In situ immunohistochemistry for CK-19 [a cholangiocyte-specific marker (3)] in frozen liver sections n=6) from BDL [a] and BDL+vagotomy [b] rats. Note that vagotomy induced a marked decrease in the number of ducts as compared with BDL control rats. Orig. magn., ×125. Reproduced with permission from reference (11). Figure 2. In situ immunohistochemistry for cellular nuclear antigen (PCNA) in liver sections from normal rats [left] and normal rats fed 1% TC [middle] or 1% TLC [right] for 1 week. Chronic feeding of TC [middle] and TLC [right] induced a significant increase in the number of PCNA-positive cholangiocytes as compared with liver sections from normal rats [left]. Reproduced with permission from reference (7). [source] Microstrip antennas for cellular and wireless communication systemsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2002obodzian Abstract The Letter describes problems related to use of microstrip antennas in cellular and wireless telecommunications systems. Because of the unique properties, microstrip technology is nowadays often used to manufacture small internal antennas for portable terminals as well as antenna arrays for base stations. It also seems to be a very promising technology for multisystem antennas, for which there is an ever-growing demand. The Letter also presents a short overview of currently available solutions and ones under development by the authors, along with some key problems related to their design. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 380,384, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10468 [source] Progress in SWNT based, SAW driven charge pumpsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2006Viktor Siegle Abstract The work presented gives a short overview of existing implementations for single electron pumps. A proposal by Talyanskii et al. [Phys. Rev. Lett. 87, 276802 (2001)] for a single walled carbon nanotube (SWNT) based device is discussed. SWNT is suggested to function as one-dimensional channel for electrons, which are driven by the surface acoustic wave (SAW). The SAW is created on the surface of a piezoelectric by lithographically defined structures. This work addresses the details in manufacturing such a device. This work investigates the possibilities of growing SWNTs by chemical vapor deposition (CVD) on the surface of LiNbO3, which is known for its excellent piezoelectric properties. The results of this study are reported together with the progress in fabrication of such a device. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Positron and positronium scatteringPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2007H. R. J. Walters Abstract A short overview of coupled-(pseudo)state methods and results for positron and positronium scattering by atomic targets is presented. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Application of Laser-Assisted Microdissection for Gene Expression Analysis of Mammalian Germ CellsANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2010R. Kenngott With 1 figure and 2 tables Summary Laser-assisted microdissection (LAM) is an important method to provide new significant insights into many embryological processes. To understand these processes, it is important to obtain specific populations of cells from complex tissue in an efficient and precise manner and to combine with many different molecular biological methods. During the last few years, the sophistication of the techniques of LAM has increased significantly and made the procedure easy to use. New micro-extraction protocols for DNA, RNA and proteins now allow broad downstream applications in the fields of genomics, transcriptomics and proteomics. In this review, we give a short overview of the application of LAM in combination with quantitative qPCR for the analysis of gene expression in mammalian germ cells. [source] Learner and information characteristics in the design of powerful learning environmentsAPPLIED COGNITIVE PSYCHOLOGY, Issue 3 2006Fred Paas This themed issue aims to present some current directions in cognitive load research. The contributions to this issue represent a compilation of symposia contributions to the 11th European Conference for Research on Learning and Instruction (EARLI), 2005, in Nicosia, Cyprus. These cognitive load symposia were focused on empirical and theoretical perspectives on designing powerful learning environments by aligning learner characteristics, information characteristics, or both with the knowledge structures underlying the cognitive architecture. This article provides an introduction to cognitive load theory and the instructional design consequences of these characteristics, and a short overview of the contributions to this issue. Copyright © 2006 John Wiley & Sons, Ltd. [source] Are potential natural vegetation maps a meaningful alternative to neutral landscape models?APPLIED VEGETATION SCIENCE, Issue 2 2002Carlo Ricotta Abstract. In this paper, we present a short overview of neutral landscape models traditionally adopted in the landscape ecological literature to differentiate landscape patterns that are the result of simple random processes from patterns that are generated from more complex ecological processes. Then, we present another family of models based on Tuxen' s definition of potential natural vegetation that play an important role, especially in Europe, for landscape planning and management. While neutral landscape models by their very nature do not take into account vegetation dynamics, nor abiotic constraints to vegetation distribution, the concept of potential natural vegetation includes the effects of vegetation dynamics in a spatially explicit manner. Therefore, we believe that distribution maps of potential natural vegetation may represent an ecological meaningful alternative to neutral landscape models for evaluating the effects of landscape structure on ecological processes. [source] EST Adaptive optics performance estimationsASTRONOMISCHE NACHRICHTEN, Issue 6 2010T. Berkefeld Abstract We give a short overview of the Adaptive Optics (AO) and Multi-conjugate Adaptive Optics (MCAO) system of the planned 4 m European Solar Telescope (EST). The optimization process of the AO / MCAO parameters is shown, including the parameters and layout of the Shack-Hartmann wavefront sensor setup and the DMs. We show the expected performance of the AO and MCAO system (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Translating pathology in multiple sclerosis: the combination of postmortem imaging, histopathology and clinical findingsACTA NEUROLOGICA SCANDINAVICA, Issue 6 2009A. Seewann Background,,, Studies combining postmortem magnetic resonance imaging (MRI) and histopathology have provided important insights into the abnormalities reflected by MRI. Materials and methods,,, A short overview of these studies applied to multiple sclerosis (MS) is provided in this review, and the Amsterdam postmortem imaging protocol is specifically highlighted. Conclusion,,, Postmortem MRI and histopathology correlation studies have enabled a direct translation of basic pathology in MS to the clinical setting, and have simultaneously served as a biological validation of new MRI techniques. [source] Early cortical lens opacities: a short overviewACTA OPHTHALMOLOGICA, Issue 6 2009Gijs F.J.M. Vrensen Abstract. Cataract is still the dominant cause of blindness worldwide. Cortical cataract is the most prevalent of the age-related changes in the human lenses that require surgical intervention to restore vision. The absence of adequate cataract surgery in most developing countries is the main cause of the high prevalence of cataract blindness worldwide. Lens ageing is accompanied by dramatic increases in stiffness, light scattering and coloration of the lens nucleus. These changes start to become manifest as early as the fourth or fifth decade of life and lead to nuclear cataract in old age. In the same period the equatorial deep lens cortex starts to show small opaque shades, which eventually grow out to segmental and annular opacities. These opaque shades are filled with small vesicles and contain abnormal amounts of cross-linked proteins, cholesterol and phospholipids. They are bordered by membranes that are rich in square arrays, have ,degenerate' gap junctions and have few intramembranous particles. It has been shown that the opaque shades represent cohorts of locally affected fibres segregated from unaffected neighbouring fibres by ,non-leaky' membranes. This segregation is an effective mechanism delaying the outgrowth of these opacities to cuneiform cataracts entering the pupillary space and thus leading to blinding cortical cataracts. Although cataract formation is mostly considered to be a multi-factorial disease, oxidative stress might be one of the leading causes for both nuclear and cortical cataract. In cortical cataracts shear stress between cortex and nucleus during accommodation may also play a significant role. [source] Structure Formation Principles and Reactivity of Organolithium CompoundsCHEMISTRY - A EUROPEAN JOURNAL, Issue 14 2009Viktoria Abstract Organolithium chemistry! An overview of the structure formation principles and the strong structure,reactivity relationship of lithium organics is given. By means of the commonly used lithium bases the deaggregation of the oligomeric parent structures to small adducts is presented (see examples) and compared to the related chemistry of lithiosilanes. The structure,reactivity relationship is an important feature of organolithium compounds. The knowledge of the structure of reactive species is crucial for the elucidation of reaction mechanisms and the understanding of observed selectivities. This concept article gives an overview over the structural principles of lithium organics and their Lewis base coordinated complexes in the solid state. The transition from the oligomeric parent structures to smaller adducts, such as dimers and monomers, as well as special degrees of aggregation is presented. Besides the commonly used alkyllithium compounds, a short overview over the structural principles of the higher homologous silyllithium compounds is given. Moreover, the structure,reactivity relationship is depicted by means of the reactivity of the Lewis bases towards intramolecular decomposition reactions with the organolithium compound. Selected examples confirm the importance of structure elucidation for the understanding of mechanistic pathways and selectivities. [source] Pyrimidine as Constituent of Natural Biologically Active CompoundsCHEMISTRY & BIODIVERSITY, Issue 1 2005Irene This review describes the various manifestations of the pyrimidine system (alkylated, glycosylated, benzo-annelated.). These comprise pyrimidine nucleosides as well as alkaloids and antibiotics , some of them have been discovered and isolated from natural sources already long time ago, others have been reported very recently. A short overview on pyrimidine syntheses (prebiotic synthesis, biosynthesis, and metabolism) is given. The biological activities of most of the pyrimidine analogs are briefly described, and, in some cases, syntheses are formulated. [source] Determination of absolute configuration,An overview related to this Special IssueCHIRALITY, Issue 5 2008Stig Allenmark Abstract Rapid progress in asymmetric synthesis stimulated a further development of methods and techniques for the determination of absolute configuration of chiral molecules. In recent years the direct methods, i.e. X-ray diffraction analysis, circular dichroism (vibrational and electronic), Raman optical activity, optical rotation measurements, as well as indirect methods for relative configuration assignment with the use of NMR spectroscopy or enzymatic transformations, are receiving increasing attention not only by specialists in the field but also by synthetic and structural chemists alike. This paper provides a short overview of the methods currently used, as well as references to contributions collected in this Thematic Issue of Chirality. Chirality, 2008. © 2008 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||