bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of RNA Arbitrarily Primed PCR Probes Hybridized to Glass cDNA Microarrays: Application to the Analysis of Limited Samples
Authors: Grau Mònica , Solé Xavier , Obrador Antònia , Tarafa Gemma , Vendrell Elisenda , Valls Joan , Moreno Victor , Peinado Miquel A , Capellá Gabriel 
Published: December 2004

Abstract
Background: The applicability of microarray-based transcriptome massive analysis is often limited by the need for large amounts of high-quality RNA. RNA arbitrarily primed PCR (RAP-PCR) is an unbiased fingerprinting PCR technique that reduces both the amount of initial material needed and the complexity of the transcriptome. The aim of this study was to evaluate the feasibility of using hybridization of RAP-PCR products as transcriptome representations to analyze differential gene expression in a microarray platform.
Methods: RAP-PCR products obtained from samples with limited availability of biological material, such as experimental metastases, were hybridized to conventional cDNA microarrays. We performed replicates of self-self hybridizations of RAP-PCR products and mathematical modeling to assess reproducibility and sources of variation.
Results: Gene/slide interaction (47.3%) and the PCR reaction (33.8%) accounted for the majority of the variability. From these observations, we designed a protocol using two pools of three independent RAP-PCR reactions coming from two independent reverse transcription reactions hybridized in duplicate and evaluated them in the analyses of paired xenograft-metastases samples. Using this approach, we found that HER2 and MMP7 may be down-regulated during distal dissemination of colorectal tumors.
Conclusion: RAP-PCR glass array hybridization can be used for transcriptome analysis of small samples.
Modified Moments and Orthogonal Rational Functions
Authors: Van Deun J. , Bultheel A. 
Published: December 2004

AbstractIn a series of articles [9, 10, 11] about the numerical computation of orthogonal polynomials on a subset of the real line, Gautschi shows that computing orthogonal polynomials starting from the moments μk = ∫ xkdμ(x) of the measure is generally an ill‐conditioned problem. However, in [10] an alternative approach is presented, based on so‐called modified moments, which works better in certain situations. In this paper we generalize these results to the computation of orthogonal rational functions and provide a new modified moment algorithm, based on the connection between modified moments and interpolatory quadrature. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of polystyrene‐supported glucosamine resin and its adsorption properties for metal ions
Authors: Sun Changmei , Qu Rongjun , Wang Chunhua , Ji Chunnuan , Cheng Guoxiang 
Published: December 2004

AbstractA novel chelating resin polystyrene‐supported glucosamine was prepared by the reaction of chloromethylated polystyrene with glucosamine hydrochlorate, using anhydrous potassium carbonate as catalyst and dimethylformamide as solvent. Infrared spectra and elementary analysis were used to confirm its structure. The adsorption of the resin for Cu2+, Ni2+, Hg2+, Co2+, Cd2+, and Pb2+ was investigated, as well as various factors affecting the adsorption such as time, temperature, ion concentration, and pH. The results showed that the resin had good adsorption capacities for Cu2+, Ni2+, and Hg2+. The adsorption was controlled by liquid film diffusion and adsorption isothermal data could be well interpreted by the Freundlich equation. Values of adsorption activation energy and adsorption Gibbs free energy were calculated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 890–896, 2005
Organosoluble and light‐colored fluorinated polyimides based on 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane and aromatic dianhydrides
Authors: Yang Chin‐Ping , Chen Ruei‐Shin , Chen Kuei‐Hung 
Published: December 2004

AbstractA novel fluorinated diamine monomer, 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane (2), was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride with 2,2‐bis(4‐hydroxyphenyl)propane in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides were synthesized from diamine 2 and various aromatic dianhydrides 3a–f via thermal imidization. These polymers had inherent viscosities ranging from 0.73 to 1.29 dL/g. Polyimides 5a–f were soluble in amide polar solvents and even in less polar solvents. These films had tensile strengths of 87–100 MPa, elongations to break of 8–29%, and initial moduli of 1.7–2.2 GPa. The glass transition temperatures (Tg) of 5a–f were in the range of 222–271°C, and the 10% weight loss temperatures (T10) of them were all above 493°C. Compared with polyimides 6 series based on 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane (BAPP) and polyimides 7 based on 2,2‐Bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane (6FBAPP), the 5 series showed better solubility and lower color intensity, dielectric constant, and lower moisture absorption. Their films had cutoff wavelengths between 363 and 404 nm,b* values ranging from 8 to 62, dielectric constants of 2.68–3.16 (1 MHz), and moisture absorptions in the range of 0.04–0.35 wt %. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 922–935, 2005
Biophysical properties of quadruple helices of modified human telomeric DNA
Authors: Petraccone Luigi , Erra Eva , Esposito Veronica , Randazzo Antonio , Galeone Aldo , Barone Guido , Giancola Concetta 
Published: December 2004

AbstractTelomeric DNA of a variety of vertebrates including humans contains the tandem repeat d(TTAGGG)n. The guanine rich strand can fold into four‐stranded G‐quadruplex structures, which have recently become attractive for biomedical research. Indeed, the aptamers based on the quadruplex motif may prove useful as tools aimed at binding and inhibiting particular proteins, catalyzing various biochemical reactions, or even serving as pharmaceutically active agents. The incorporation of modified bases into oligonucleotides can have profound effects on their folding and may produce useful changes in physical and biological properties of the resulting DNA fragments. In this work, the adenines of the human telomeric repeat oligonucleotide d(TAGGGT) and d(AGGGT) were substituted by 2′‐deoxy–8‐(propyn‐1‐yl)adenosine (A→APr) or by 8‐bromodeoxyadenosine (A→ABr). The biophysical properties of the resulting quadruplex structures were compared with the unmodified quadruplexes. NMR and CD spectra of the studied sequences were characteristic of parallel‐stranded, tetramolecular quadruplexes. The analysis of the equilibrium melting curves reveals that the modifications stabilize the quadruplex structure. The results are useful when considering the design of novel aptameric nucleic acids with diverse molecular recognition capabilities that would not be present using native RNA/DNA sequences. © 2004 Wiley Periodicals, Inc. Biopolymers, 2005
[Aladan3]TIPP: A fluorescent δ‐opioid antagonist with high δ‐receptor binding affinity and δ selectivity
Authors: Chen Heru , Chung Nga N. , Lemieux Carole , Zelent Bogumil , Vanderkooi Jane M. , Gryczynski Ignacy , Wilkes Brian C. , Schiller Peter W. 
Published: December 2004

AbstractFluorescent analogues of the potent and highly selective δ‐opioid antagonist TIPP (HTyrTicPhePheOH) and TIP (HTyrTicPheOH) containing the exceptionally environmentally sensitive fluorescent amino acid β‐(6′‐dimethylamino‐2′‐naphthoyl)alanine (Aladan [Ald]) in place of Phe3 were synthesized. The Ald3‐ and D‐Ald3 analogues of TIPP and TIP all retained δ‐opioid antagonist properties. The most potent analogue, [Ald3]TIPP, showed a Ke value of 2.03 nM in the mouse vas deferens assay and five times higher δ vs. μ selectivity (K/K = 7930) than the TIPP parent peptide in the opioid receptor binding assays. Theoretical conformational analyses of [Ald3]TIPP and [Ald3]TIP using molecular mechanics calculations resulted in a number of low‐energy conformers, including some showing various patterns of aromatic ring stacking and others with the Ald side chain and a carbonyl group (fluorescence quencher) in close proximity. These ensembles of low‐energy conformers are in agreement with the results of steady‐state fluorescence experiments (fluorescence emission maxima and quantum yields) and fluorescence decay measurements (fluorescence lifetime components), which indicated that the fluorophore was either engaged in intramolecular hydrophobic interactions or in proximity of a fluorescence quencher (e.g., a carbonyl group). These fluorescent TIP(P) δ‐opioid antagonists represent valuable pharmacological tools for various applications, including studies on membrane interactions, binding to receptors, cellular uptake and intracellular distribution, and tissue distribution. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2005
Child protection in the community: a community development approach
Authors: Wright Sarah 
Published: December 2004

AbstractThis article describes the development of a community work project which aims to address issues relating to the safety of children within their communities. The project's work is underpinned by an ecological theory of child abuse and embraces a community development approach. The approach aims to engage local communities in deﬁning issues relevant to them and in identifying strategies for addressing these issues. The project has engaged in a mixture of direct service delivery, inﬂuencing and networking activities and ‘community capacity building’ activities. As the project has developed, the remit of its work has become increasingly deﬁned by local people. Market research was undertaken to promote an understanding of the things that children and parents felt affected children's safety locally. A community conference was organized to promote awareness about the issues that were identiﬁed and to engage local policy‐makers and professionals in discussing potential solutions with community members. A youth forum has been established to enable young people to inﬂuence local decision‐making about issues that affect their safety and well‐being within the community. The community development approach is seen as being effective in helping young people to inﬂuence their environment and in reducing vulnerability through promoting self‐esteem. Copyright © 2004 John Wiley & Sons, Ltd.
Odor and (Bio)diversity: Single Enantiomers of Chiral Fragrant Substances
Authors: Abate Agnese , Brenna Elisabetta , Fuganti Claudio , Gatti Francesco G. , Serra Stefano 
Published: December 2004

AbstractOur sense of smell is enantioselective. This review reports interesting examples of single stereoisomers of natural and synthetic odorants, prepared via bioorganic routes, that support this statement. This article is the summary of a talk given at the Flavours & Fragrances 2004 conference in Manchester at the MCC/UMIST, 12–14 May, 2004.
A Novel Approach to Prezizaane Sesquiterpenes
Authors: Goeke Andreas , Mertl Daniel , Brunner Gerhard 
Published: December 2004

AbstractPrezizaane sesquiterpenes are an olfactorily interesting class of tricyclic natural products, which occur in some precious perfumery raw materials. These compounds are biosynthetically derived from farnesyl pyrophosphate via cyclization, but some questions regarding the stereoselectivity of this process have not yet been answered. We discuss a novel and concise access to the tricyclic framework of these sesquiterpenes, as exemplified by the synthesis of (±)‐5‐epi‐sesquithuriferone (5‐epi‐4).
The effect of glutamine supplementation on the function of neutrophils from exercised rats
Authors: Lagranha Claudia Jacques , Martins de Lima Thais , Senna Sueli Moreno , Doi Sonia Quatelli , Curi Rui , Pithon‐Curi Tania Cristina 
Published: December 2004

AbstractIn a recent publication, we showed the protective effect of glutamine on neutrophil apoptosis induced by acute exercise. The purpose of the present study was to examine the effect of a single bout of intensive exercise on rat neutrophil function and the possible effect of glutamine supplementation. An aqueous solution of glutamine was given by gavage (1 g per kg b.w.), 1 h before the exercise session. The exercise was carried out on a treadmill for 1 h at 85% VO2máx.. Neutrophils were obtained by intraperitoneal lavage with PBS. The following parameters were evaluated: phagocytosis capacity, production of nitric oxide and reactive oxygen metabolites, expression of iNOS, and expression of NADPH‐oxidase components (p22phox, p47phoxand gp91phox). One hour of exercise at 85% VO2max.induced no change in the phagocytosis capacity and reactive oxygen species production but decreased nitric oxide production. When rats received oral glutamine supplementation, the phagocytosis capacity was significantly increased, the decrease in nitric oxide production induced by exercise was abolished and production of reactive oxygen species was raised. Glutamine supplementation presents a significant effect on neutrophil function including changes induced by exercise. Copyright © 2004 John Wiley & Sons, Ltd.
Crystal Field and Magnetic Ordering in the Haldane‐Chain Compound Er2BaNiO5 as Studied by Optical Spectroscopy.
Authors: Popova M. N. , Klimin S. A. , Chukalina E. P. , Levitin R. Z. , Mill B. V. , Malkin B. Z. , Antic‐Fidancev E. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Syntheses and Structures of Ln10Ni9+xIn20 (Ln: Tb, Dy) and YbNiIn2.
Authors: Zaremba Vasyl I. , Muts Ihor R. , Rodewald Ute Ch. , Hlukhyy Viktor , Poettgen Rainer 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Regio‐ and Stereoselective Transfer of p‐Toluenesulfonamido Group from Sulfur to Carbon: Preparation of Amino Alcohol Derivatives from Allyl Alcohols.
Authors: Raghavan Sadagopan , Kumar Ch. Naveen , Tony K. A. , Reddy S. Ramakrishna , Kumar K. Ravi 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Convenient and Highly Efficient Method for the Protection of Aldehydes Using Very Low Loading Hydrous Ruthenium(III) Trichloride as Catalyst.
Authors: Qi Jian‐Ying , Ji Jian‐Xin , Yueng Chi‐Hung , Kwong Hoi‐Lun , Chan Albert S. C. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Hypoglycemic Activities of 3‐(Phthalimidomethyl)‐4‐substituted‐cinnamoyl Salicylanilides.
Authors: Sahu S. K. , Mishra S. K. , Mahapatra S. P. , Bhatta D. , Panda C. S. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Studies on Novel Synthetic Methodologies. Part 51. Hypervalent Iodine‐Mediated Interaction of Aldoximes with Activated Alkenes Including Baylis—Hillman Adducts: A New and Efficient Method for the Preparation of Nitrile Oxides from Aldoximes.
Authors: Das Biswanath , Holla Harish , Mahender Gurram , Banerjee Joydeep , Reddy Majjigapu Ravinder 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
3‐(Difluoro‐λ3‐iodanyl)‐4‐methylfurazan: The First Representative of (Difluoro‐λ3‐iodanyl)azoles
Authors: Sheremetev A. B. , Dmitriev D. E. , Konkina S. M. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis and Evaluation of 4‐(1‐Aminoalkyl)‐N‐(4‐pyridyl)cyclohexanecarboxamides as Rho Kinase Inhibitors and Neurite Outgrowth Promoters.
Authors: Gingras Karine , Avedissian Hovsep , Thouin Eryk , Boulanger Veronique , Essagian Charles , McKerracher Lisa , Lubell William D. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Regioisomerism in the Ritter Reaction. Part 1. Synthesis of 3,3,5,6,7‐, 3,3,6,7,8‐, 3,3,5,7,8‐, and 3,3,5,6,8‐Pentamethyl‐3,4‐dihydroisoquinolines from 1,2,3‐ and 1,2,4‐Trimethylbenzenes.
Authors: Shklyaev Yu. V. , Ismagilov R. R. , Rozhkova Yu. S. , Fatykhov A. A. , Abdrakhmanov I. B. , Tolstikov A. G. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Versatile Approach for the Synthesis of 1‐Methyl‐4H[1,2,4]triazolo[4,3‐a][1,4]benzodiazepine N5‐Oxide.
Authors: Gupta Anjul , Sirohi Reenu , Shastri Sudha , Kishore D. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Novel Approach for the Synthesis of 5‐Methoxycarbonyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one‐N 4‐oxides from N‐Chloroacetylisatins.
Authors: Sirohi Reenu , Singh Anjul , Shastri Sudha , Kishore D. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Pyrrolo[2,1‐c][1,4]benzodiazepine—Anthraquinone Conjugates. Synthesis, DNA Binding and Cytotoxicity.
Authors: Kamal Ahmed , Ramu R. , Khanna G. B. Ramesh , Saxena Ajit Kumar , Shanmugavel M. , Pandita Renu Moti 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Azomethine Ylides Derived from Dichlorocarbene and O‐Acylsalicylaldehyde Anils in the Synthesis of 2,5‐Epoxy‐2,3,4,5‐tetrahydro‐1,4‐benzoxazepin‐2‐ones and 2‐Aminoethanols.
Authors: Voznyi I. V. , Novikov M. S. , Khlebnikov A. F. , Kostikov R. R. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Two New Cucurbitacin Glucosides, Opercurins A (I) and B (II), from the Brazilian Folk Medicine “Buchinha” (Luffa operculata)
Authors: Kawahara Nobuo , Kurata Atsuyo , Hakamatsuka Takashi , Sekita Setsuko , Satake Motoyoshi 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Isolation, Crystal and Solution Structure Determination, and Biosynthesis of Tubulysins — Powerful Inhibitors of Tubulin Polymerization from Myxobacteria
Authors: Steinmetz Heinrich , Glaser Nicole , Herdtweck Eberhardt , Sasse Florenz , Reichenbach Hans , Hoefle Gerhard 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 3‐Tetra‐O‐benzoyl‐β‐D‐glucopyranosylimino‐4‐phenyl‐5‐arylimino‐1,2, 4‐dithiazolidines.
Authors: Dhonde M. G. , Deshmukh S. P. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Asymmetric Synthesis of the Stereoisomers of 11,12,15(S)‐Trihydroxyeicosa‐5(Z),8(Z),13(E)‐trienoic Acid, a Potent Endothelium‐Derived Vasodilator.
Authors: Falck J. R. , Barma Deb K. , Mohapatra Suchismita , Bandyopadhyay A. , Reddy Komandla Malla , Qi Jianjun , Campbell William B. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Three 5H‐Indeno[1,2‐c]pyridazin‐5‐one Derivatives, Potent Type‐B Monoamine Oxidase Inhibitors.
Authors: Frederick Raphael , Norberg Bernadette , Durant Francois , Ooms Frederic , Wouters Johan 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Chemical Behavior of Dubnium in HF
Authors: Tsukada K. , Haba H. , Asai M. , Toyoshima A. , Akiyama K. , Nishinaka I. , Hashimoto K. , Ichikawa S. , Nagame Y. , Yasuda K. , et al. et al. 
Published: December 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Brennstoffzellen—moderne elektrochemische Stromquellen
Authors: Euler Karl Joachim 
Published: December 2004

AbstractAuch Automobile haben so etwas wie einen Stoffwechsel. Ihre Ausscheidungsprodukte riechen nicht besonders gut, und zum Teil sind sie auch giftig. Die Kohlenmonoxid‐Konzentration der Großstadtluft an belebten Plätzen und zur Hauptverkehrszeit erreicht bereits heute beachtliche Werte. Damit man nicht eines Tages mit der Gasmaske durch unsere Straßen wird gehen müssen, sucht man allenthalben nach Wegen, Fahrzeuge ohne derart störende Begleiterscheinungen zu bauen; so entwickelt z. B. die Automobilindustrie Vorrichtungen zur Abgasentgiftung. Ein anderer Versuch ist die Rückkehr zum fast ausgestorbenen Elektro‐Auto mit neuen, leistungsfähigen Stromquellen: Brennstoffzellen. Wie sie funktionieren und wozu man sie sonst noch brauchen kann, schildert dieser Bericht. (Photo Müller/Sz‐Archiv)
Physikalische Methoden in der Chemie: Massenspektrometrie II
Authors: Lehmann Wolf Dieter , Schulten Hans‐Rolf 
Published: December 2004

AbstractDie Felddesorptions‐Methode erweitert den Bereich der anorganischen und organischen Verbindungen, die der massenspektrometrischen Analyse zugänglich sind, weil ein Verdampfungsprozeß der Probe entfällt und der schonende Ionisierungsprozeß relativ stabile Ionen erzeugt. Diese Erweiterung erstreckt sich sowohl auf Verbindungen geringer oder extrem geringer Flüchtigkeit (Salze) als auch auf Verbindungen mit hohem Molekulargewicht (> 1000). Die Methode wird aussichtsreich bei analytischen Problemen angewendet, bei denen andere massenspektrometrische Techniken versagen und bei denen nur Probenmengen zwischen 10−6 und 10−9g zur Verfügung stehen.
Das Portrait: Franz Ritter von Kobell (1803–1882)
Authors: Krätz Otto 
Published: December 2004

AbstractFranz von Kobell 1857, im 54. Lebensjahr, mit Manuskriptblatt und Lodenjoppe. Diese Portraitaufnahme wurde ebenso wie die Poccis und Steinheils (Seite 157) von Franz Hanfstaengl angefertigt. Die Photos sind dem „Album der Zeitgenossen, Photos von 1853 bis 1863”︁ (hrsg. von Ch. Diener und G. Fulton‐Smith) entnommen.
Metallcluster. Studienobjekte der Metallbildung
Authors: Schmid Günter 
Published: December 2004

AbstractEtwa drei Viertel aller Elemente sind Metalle. Sie begegnen uns einerseits in einer fast unübersehbaren Fülle von Komplexen, in denen sie geladen oder neutral, aber überwiegend einzeln von einer geeigneten Ligandhülle umgeben vorliegen. Auf der anderen Seite kennen wir recht gut den metallischen Zustand, also jene Ansammlung von praktisch unendlich vielen Metallatomen, die im Zusammenwirken die sogenannten metallischen Eigenschaften, wie die elektrische und die Wärmeleitfähigkeit, das magnetische Verhalten, die Duktilität u.a., erzeugen. Was aber liegt dazwischen?Gibt es einen kontinuierlichen Übergang vom einfachen ein‐ oder zweikernigen Komplex zum kompakten Metall? Die ersten Schritte auf dem Weg zur Klärung dieser Frage sind gemacht! Man kennt heute vielkernige, aber noch molekulare Komplexe, die über 500 Metallatome enthalten. Wo fängt der metallische Zustand an? Wie viele Atome sind notwendig, um metallische Eigenschaften zu erzeugen? Niemand kann diese fundamentalen Fragen zur Zeit zuverlässig beantworten. Sicher wird das, was wir metallischen Zustand nennen, nicht plötzlich bei Erreichen einer bestimmten Zahl von Metallatomen auftauchen. Vielmehr wird sich diese Eigenschaft allmählich und temperaturabhängig einstellen. Trotzdem bleibt die faszinierende Frage nach der ungefähren Zahl von Atomen, die zur Erzeugung der kleinsten Metallpartikel nötig ist.Ansammlungen von einigen wenigen bis zu hunderten von Atomen bezeichnet man als Cluster, wobei es an Bemühungen, diese recht pauschale Definition zu verfeinern, nicht gefehlt hat [1]. Irgendwann sprechen wir dann von Mikrokristalliten, wenn die Partikel ohne großen Aufwand sichtbar gemacht werden können, z. B. in einem guten Lichtmikroskop oder mit Hilfe eines einfachen Elektronenmikroskops. In diesen Bereich gehören z. B. auch die Metallkolloide. Physiker und Chemiker haben sich in den vergangenen 20 Jahren viele Methoden einfallen lassen, um Metallcluster zu erzeugen. Dabei unterscheidet man zwischen den sogenannten „nackten”︁, d. h. ligandfreien Clustern und Clustern, die durch eine Ligandhülle geschützt sind (chemisch stabilisierte Cluster). Nackte und ligandstabilisierte Metallcluster werden jedoch nicht nur untersucht, um die für den metallischen Zustand erforderliche Zahl von Atomen zu ermitteln, sondern auch aus vielen anderen Gründen. So liefert das Studium der Clusterstrukturen Einblick in den Entstehungsprozeß von Metallkristalliten, von Metallclustern erhofft man sich neuartige Materialeigenschaften, der Chemiker erwartet Aufschlüsse über elementare Vorgänge bei der homogenen und heterogenen Katalyse. Gründe genug also, um sich weltweit mit dem Phänomen der Clusterbildung zu beschäftigen.