bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving self-defense in plants. Martial arts for vegetables
Authors: Moyna Patrick , Heinzen Horacio 
Published: October 2007

Abstract
From the dawn of agriculture there has been an ever-intensifying human effort to improve yields by having crops with enhanced biological similarity (i.e., characteristics of product, maturation time, height, color, etc.). The ultimate stage is to plant a crop where all individuals behave in exactly the same way, being clones of each other. This very intensive approach leads to loss of intrapopulation biodiversity and to unstable systems, prone to disastrous losses should anything go wrong.
Biological evolutionary success is usually derived from high adaptability to ever-changing external conditions. Highly specialized plants (such as certain orchids) or animals survive by correctly performing a high-wire act of enormous risk. External disbalances have catastrophic results on these species. Nature excels and corrects imbalances increased biodiversity within natural populations. Given this situation, we should study the defensive systems used by plants and improve on those natural systems.
Selectivity in analytical chemistry (IUPAC Recommendations 2001)
Authors: Vessman Jörgen , Stefan Raluca I. , van Staden Jacobus F. , Danzer Klaus , Lindner Wolfgang , Burns Duncan Thorburn , Fajgelj Aleš , Müller Helmut 
Published: October 2007

Abstract
The correct use of the term "selectivity" and its clear distinction from the term "specificity" are discussed. A definition of selectivity is given, and it is recommended that the use of this term be promoted and that the use of the term "specificity" be discouraged.
Molecular recognition at kappa opioid receptors
Authors: Portoghese Philip S. 
Published: October 2007

Abstract
Structure­activity relationships are rarely straightforward, and often are more complicated than they appear. For this reason, the use of site-directed mutagenesis as a complementary tool to analyze structure­activity relationships has been invaluable. Here, we illustrate how site-directed mutagenesis has led to greater insight into the molecular basis for molecular recognition of norbinaltorphimine and to the design of novel kappa antagonists. Given the paucity of high-resolution crystal structures for membrane-bound receptors, the use of a coordinated "two-dimensional" paradigm that involves molecular modification of both the ligand and the receptor, affords a useful approach to the study of molecular recognition. This paradigm has led to the design of highly potent and selective kappa opioid receptor antagonists that are derivatives of the delta opioid receptor antagonist, naltrindole.
Semicarbazide-sensitive amine oxidase. Its physiological significance
Authors: Magyar K. , Mészáros Z. , Mátyus P. 
Published: October 2007

Abstract
Although the existence of plasma- and tissue-bound semicarbazide-sensitive amine oxidases (SSAOs) has been recognized earlier, the physiological relevance of the enzyme still remains uncertain. Recent data suggest that elevated serum SSAO activity might cause endothelial injury. Formation of cytotoxic metabolites (e.g., formaldehyde) and increased oxidative stress might lead to initiation or progression of atherosclerosis. Significant positive correlation was found between serum SSAO activity and severity of atherosclerosis, and diabetic macrovascular complications. Effective and selective inhibitors of human SSAO might exert cytoprotective effect on endothelial cells. Compounds, having similar structure to mexiletine, were synthesized and studied relating to SSAO activity. The reference substrate was MDL-72974A. Unfortunately, our new compounds did not reach the potency of the reference substance using human serum samples. In conclusion, we suppose that vascular and soluble SSAO enzymes might have different inhibitor sensitivity. Further studies are required to determine whether the soluble or vascular isoform of SSAO will be the main therapeutic target in the future.
Chemical development of the vasopressin receptor 2 antagonist SR-121463
Authors: Hermecz István , Sánta-Csutor Andrea , Gönczi Csaba , Héja Gergely , Csikós Éva , Simon Kálmán , Smelkó-Esek Ágota , Podányi Benjámin 
Published: October 2007

Abstract
A facile convergent total synthesis of the selective, potent, and orally active V2 non-peptide antagonist, SR-121463, was developed by modification of the discovery route. One of the late intermediates, the sulfonyl chloride 1, was synthesized from 3-hydroxybenzoic acid (19) by regioselective sulfonation, O-methylation and amidation in four steps. Another late intermediate, indolin-2-one 2, was prepared from p-phenetidine (8) through the indolin-2-one 16, where the cyclohexanone moiety of 27 was introduced into the active 3-methylene group of 16 by sequential transformation using methyl acrylate and KOtBu. After formation of the cyclic ketal moiety of 13, its ring-opening was achieved by using NaBH4 in the presence of CCl3COOH. The morpholino group in 2 was introduced in accordance with the discovery approach, starting from the 2-hydroxyethoxy derivative 14 through the tosyloxy derivative 15 with morpholine in a one-pot reaction. In this way, the indolin-2-one 2 was synthesized from 8 in six steps. Finally, acylation of the indolin-2-one 2 was achieved with the sulfonyl chloride 1 in the presence of KOtBu in dimethyl sulfoxide (DMSO) at room temperature. This synthetic route proved to be applicable for the large-scale synthesis of SR-121463.
NMR spectroscopy in drug design
Authors: Heller Markus , Kessler Horst 
Published: October 2007

Abstract
The process of preclinical drug discovery consists of two steps: finding of initial hits (binding ligands to a medicinal relevant target, usually a protein) and lead optimization. Nuclear magnetic resonance spectroscopy is a powerful tool that can provide valuable information to every step of drug development. NMR is commonly used for characterizing the structure and molecular dynamics of target or ligand molecules. During the structure-based lead optimization, NMR provides insight into the structural and dynamical properties of the target-ligand complex. Recently, the use of NMR in the lead finding process by screening technologies has been shown. For the latter use, new techniques have also been developed. Those techniques, in combination with high throughput, have lead to an efficient screening of libraries composed of small molecules. In this article, the role of NMR during the discovery of a drug candidate is described.
New chemical structures of hypolipidemic and antiplatelet activity
Authors: Chilmonczyk Z. , Siluk D. , Kaliszan R. , Łozowicka B. , Popławski J. , Filipek S. 
Published: October 2007

Abstract
Elevated lipid level is supposed to be one of the main risk factors of atherosclerosis and subsequent cardiovascular disease (and is connected to mortality). Therefore, lipid lowering is one of the major targets in cardiovascular disease treatment and prevention. Also, blood platelets play a pivotal role in the development of atherosclerosis and fatal thrombus formation in the course of coronary heart disease. Therefore, there is a great necessity to acquire drugs inhibiting platelet aggregation and clot generation. The present paper reviews new chemical structures in development for the treatment and prevention of hyperlipidemia, atherosclerosis, and subsequent cardiovascular disease. The authors' recent results are also reported regarding synthesis of a new group of a-asarone analogs. These compounds were identified as an original class of agents exhibiting hypolipidemic and antiplatelet (mice, rats) activities. Although the mechanism of the compounds' pharmacological activity has not been identified, quantum-mechanical calculations allowed structural requirements to be described that correspond to the activity (a hypothetical pseudoreceptor structure). Since it is known that asarone and its derivatives may exhibit genotoxicity, calculations were carried out to identify derivatives of possibly low genotoxic activity.
Opioid and sigma receptor studies. New developments in the design of selective sigma ligands
Authors: Ronsisvalle Giuseppe , Marrazzo Agostino , Prezzavento Orazio , Cagnotto Alfredo , Mennini Tiziana , Parenti Carmela , Scoto Giovanna M. 
Published: October 2007

Abstract
New racemic and chiral methyl 2-{[4-(4-chlorophenyl)-4-hydroxypiperi-din-1-yl]methyl}-1-phenylcyclopropanecarboxylate derivatives were synthesized in order to obtain sigma ligands with increased affinity and selectivity compared to (+)-MPCB and haloperidol. The cis-(±)-7 racemic mixture showed a better binding affinity and selectivity than the (±)-8 trans isomers. Between the two cis enantiomers, (+)-7, with configuration (1R,2S), showed a very high affinity and the best selectivity for s1. All compounds synthesized (7­9) showed a reduced or negligible affinity for opioid and dopaminergic D1 and D2 receptors. Nociceptive in vivo test confirms that (+)-7 (namely MR200), such as non-selective antagonist haloperidol, increased the analgesic effect induced by the k opioid selective ligand U50,488H and reversed the inhibiting effect of (+)-pentazocine on analgesia.
Generic source-based nomenclature for polymers(IUPAC Recommendations 2001)
Authors: Maréchal E. , Wilks E. S. 
Published: October 2007

Abstract
The commission has already published two documents on the source-based names of linear copolymers and nonlinear polymers; however, in some cases this nomenclature leads to ambiguous names. The present document proposes a generic source-based nomenclature that solves these problems and yields clearer source-based names. A generic source-based name comprises two parts:

polymer class (generic) name followed by a colon

2) the actual or hypothetical monomer name(s), always parenthesized in the case of a copolymer

The formula, the structure-based name, the source-based name, and the generic source-based name of the polymer are given for each example in the document. In some cases, only generic source-based give unambiguous names, for example, when a polymer has more than one name or when it is obtained through a series of intermediate structures. The rules concern mostly polymers with one or more types of functional group or heterocyclic system in the main chain, but to some extent they are also applicable to polymers with side-groups, carbon-chain polymers such as vinyl or diene polymers, spiro and cyclic polymers, and networks.
Prepared by a Working Group consisting of R. E. Bareiss (Germany), R. B. Fox (USA), K. Hatada (Japan), K. Horie (UK), A. D. Jenkins (UK), J. Kahovec (Czech Republic), P. Kubisa (Poland), E. Maréchal (France), I. Meisel (Germany), W. V. Metanomski (USA), I. Mita (Japan), R. F. T. Stepto (UK), and E. S. Wilks (USA)
Quantum chemical B3LYP/cc-pvqz computation of ground-state structures and properties of small molecules with atoms of Z ≤ 18 (hydrogen to argon)(IUPAC Technical Report)
Authors: Janoschek Rudolf 
Published: October 2007

Abstract
Since density functional theory (DFT) achieved a remarkable break-through in computational chemistry, the important general question "How reliable are quantum chemical calculations for spectroscopic properties?" should be answered anew. In this project, the most successful density functionals, namely the Becke B3LYP functionals, and the correlation-consistent polarized valence quadruple zeta basis sets (cc-pvqz) are applied to small molecules. In particular, the complete set of experimentally known diatomic molecules formed by the atoms H to Ar (these are 214 species) is uniformly calculated, and calculated spectroscopic properties are compared with experimental ones. Computationally demanding molecules, such as open-shell systems, anions, or noble gas compounds, are included in this study. Investigated spectroscopic properties are spectroscopic ground state, equilibrium internuclear distance, harmonic vibrational wavenumber, anharmonicity, vibrational absolute absorption intensity, electric dipole moment, ionization potential, and dissociation energy. The same computational method has also been applied to the ground-state geometries of 56 polyatomic molecules up to the size of benzene. Special sections are dedicated to nuclear magnetic resonance (NMR) chemical shifts and isotropic hyperfine coupling constants. Each set of systems for a chosen property is statistically analyzed, and the above important question "How reliable...?" is mathematically answered by the mean absolute deviation between calculated and experimental data, as well as by the worst agreement. In addition to presentation of numerous quantum chemically calculated spectroscopic properties, a corresponding updated list of references for experimentally determined properties is presented.
Evolution and revolution in instrumentation for plasma-source mass spectrometry
Authors: Hieftje Gary M. , Barnes James H. , Grøn Ole A. , Leach Andrew M. , McClenathan Denise M. , Ray Steven J. , Solyom David A. , Wetzel William C. , Denton M. Bonner , Koppenaal David W. 
Published: October 2007

Abstract
Plasma-source mass spectrometry, usually in the form of inductively coupled plasma mass spectrometry (ICP-MS), has matured into a widely accepted method for ultra-trace multielemental analysis. However, the method exhibits shortcomings. For example, it does not provide adequate precision for isotope ratio measurements if many isotopes are to be determined. Moreover, isobaric overlaps (spectral interferences) can be very troublesome in some situations. Similarly, matrix interferences can adversely affect many determinations. Yet, it is in the area of high-speed transient measurements that ICP-MS perhaps suffers its greatest weakness. When sampling devices such as flow injection, laser ablation, electrothermal vaporization, or chromatography are employed, the user must choose between broad elemental or isotopic coverage and signal-to-noise ratio (S/N). In turn, compromised S/N means lower precision or poorer detection limits. Here, new instrumentation aimed at overcoming these limitations will be described. One system, based on a time-of-flight mass spectrometer, provides excellent detection limits, resolving power better than commercial quadrupole mass filters, precision of at least 0.02% rsd in a ratioing mode, and extraordinarily high speed for use with transient sampling devices. The second instrument is based on a sector-field mass spectrometer but, unlike other such units, is equipped with a focal-plane array detector. So equipped, the system can detect a broad mass range at once.
Exploring new opportunities with sum-frequency nonlinear optical spectroscopy
Authors: Shen Y. R. 
Published: October 2007

Abstract
Over the last decade, infrared-visible sum-frequency generation has been developed into a powerful vibrational spectroscopic technique, especially for surface studies. We give here a brief review of the technique and a few recent applications of the technique to liquid and polymer surfaces. We also describe how the technique has found unique applications in our studies of surface melting of ice, ferroelectric ice films, and molecular chirality in chiral liquids. Doubly resonant sum-frequency generation as surface-specific two-dimensional spectroscopy is discussed.
Subtle order in settling suspensions
Authors: Ackerson B. J. , Lei X. L. , Tong P. 
Published: October 2007

Abstract
A dilute suspension of uniform, non-Brownian spheres settles slowly in a viscous solvent. The initially well-mixed system showing Poisson or random occupancy statistics evolves to a system having reduced number fluctuations, but otherwise appearing random. The reduced number fluctuations are consistent with recent measurements of velocity fluctuations in settling suspensions. These experimental results test the assumptions leading to the theoretical predictions by Calflisch and Luke that the velocity fluctuations increase without limit with increasing sample dimension. The theoretical prediction assumes Poisson occupation statistics contrary to our observations.
Charge-stabilized colloidal suspensions. Phase behavior and effects of confinement
Authors: Klein R. , von Grünberg H. H. 
Published: October 2007

Abstract
The Poisson­Boltzmann (PB) equation is used to investigate effective colloid-interface interactions and the phase behavior of charge-stabilized colloidal suspensions. When a colloidal particle, immersed in an electrolyte, approaches an interface, which may be neutral (such as air) or charged (like electrodes, glass, etc.), image charge effects plus the deformation of the colloidal ion atmosphere by the interface lead to an effective interaction which can be attractive or repulsive, depending on the surface charge density and the dielectric constants of the interface and the electrolyte. Two cases are considered: i) a spherical particle near a like-charged interface, and ii) a rod-like particle in the vicinity of an oppositely charged interface. The latter serves as a model for the adsorption of (anionic) DNA on a cationic membrane, and it is shown that the effective attraction, induced by the release of counterions on approach of the DNA to the membrane, makes up an essential contribution to the total DNA-membrane effective interaction. To understand the phase behavior of charge-stabilized colloidal suspensions, we study a PB cell model of a bulk suspension and investigate how the PB equation can best be linearized. It is found that the previously predicted gas­liquid phase coexistence results when the PB equation is linearized about the Donnan potential. No indication of such a spinodal instability could, however, be found, when the free energy is evaluated using the numerical solution of the full PB equation. This suggests that the predicted gas­liquid phase coexistence is an artifact of the linearization.
Guidelines for the representation of pulse sequences for solution-state nuclear magnetic resonance spectrometry (IUPAC Recommendations 2001)
Authors: Davies Antony N. , Lambert Jörg , Lancashire Robert J. , Lampen Peter , Conover Woody , Frey Michael , Grzonka Michael , Williams Evan , Meinhart Douglas 
Published: October 2007

Abstract
In drawing up the specifications for a standard for multidimensional nuclear magnetic resonance spectroscopy (NMR) it became clear that the spectroscopic data content needed to be qualified by experimental condition information especially pertaining to the pulse sequences used to obtain the free induced decays or spectra. Failure to include this information not only severely inhibits the ability of subsequent data handling packages to work with the experimental data, but also makes interpretation of the final results virtually impossible.
This paper has been produced in collaboration with the NMR spectrometer manufacturers in an attempt to get agreement on a definitive list of the most frequently used pulse sequence programs. The list includes entries where common agreement has been reached as to the acronym to name the experiment and the key instrument independent parameters needed to report concisely.
It is not intended to restrict in any way the freedom of manufacturers or users to develop new and novel experimental pulse sequences, but should aid reporting of experimental data where the more common sequences are in use.
JCAMP-DX. A standard format for the exchange of ion mobility spectrometry data (IUPAC Recommendations 2001)
Authors: Baumbach Jörg Ingo , Davies Antony N. , Lampen Peter , Schmidt Hartwig 
Published: October 2007

Abstract
The relatively young field of ion mobility spectrometry has now advanced to the stage where the need to reliably exchange the spectroscopic data obtained worldwide by this technique has become extremely urgent. To assist in the validation of the various new spectrometer designs and to assist in inter-comparisons between different laboratories reference data collections are being established for which an internationally recognized electronic data exchange format is essential.
To make the data exchange between users and system administration possible, it is important to define a file format specially made for the requirements of ion mobility spectrometry. The format should be computer readable and flexible enough for extensive comments to be included. In this document, we define a data exchange format, agreed on by a working group of the International Society for Ion Mobility Spectrometry at Hilton Head Island, USA (1998) and Buxton, UK (1999).
This definition of this format is based on the IUPAC JCAMP-DX protocols, which were developed for the exchange of infrared spectra [1] and extended to chemical structures [2], nuclear magnetic resonance data [3], and mass spectra [4]. This standard of the Joint Committee on Atomic and Molecular Physical Data is of a flexible design. The International Union of Pure and Applied Chemistry have taken over the support and development of these standards and recently brought out an extension to cover year 2000 compatible date strings and good laboratory practice [5]. The aim of this paper is to adapt JCAMP-DX to the special requirements of ion mobility spectra [6].
NMR nomenclature. Nuclear spin properties and conventions for chemical shifts(IUPAC Recommendations 2001)
Authors: Harris Robin K. , Becker Edwin D. , Cabral de Menezes Sonia M. , Goodfellow Robin , Granger Pierre 
Published: October 2007

Abstract
A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1H resonance of tetramethylsilane (TMS). The unified scale is designed to provide a precise ratio, Ξ, of the resonance frequency of a given nuclide to that of the primary reference, the 1H resonance of TMS in dilute solution (volume fraction, φ < 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples, and values of Ξ for secondary references on the unified scale are listed, many of which are the results of new measurements.
Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, δ, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic-angle spinning. In all, nine new recommendations relating to chemical shifts are made.
Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with nonzero quantum numbers. The information given includes quantum numbers, isotopic abundances, magnetic moments, magnetogyric ratios and receptivities, together with quadrupole moments and line-width factors where appropriate.
Photocatalytic transformation of organic compounds in the presence of inorganic ions
Authors: Calza Paola , Pelizzetti Ezio 
Published: October 2007

Abstract
The influence of halide ions on the photocatalytic process on titanium dioxide has been investigated carefully. Chloride and bromide ions, acting as hole scavengers, generate active radical species (e.g., ·Cl and ·Br) that participate in reactions with the organic compounds and the transient intermediates. Chloride and bromide ions have shown to deeply inhibit the degradation rate of chloroform and tetrachloromethane and to modify both the qualitative and quantitative distribution of their intermediates formed during the degradation process. In the presence of bromide, CBrCl3 is detected as intermediate during CCl4 degradation, while in the presence of chloride, formation of CCl4 is observed in the CHCl3 degradation. Fluoride ions, differently from the other halides, cannot be oxidized by the valence hole and may be used as a diagnostic tool in mechanistic studies. The influence of fluoride on phenol has been investigated, and, by choosing appropriate experimental conditions, it was possible to evaluate the role of the different active species in the photocatalytic process.