bluuebunny/crossref_metadata_2025 huggingface dataset:
Curing and post‐curing luminescence in an epoxy resin
Authors: Gallot‐Lavallée O. , Teyssedre G. , Laurent C. , Robiani S. , Rowe S.
Published: February 2006

A spontaneous luminescence is reported when epoxy resin samples are heated in air. This phenomenon is very sensitive to the nature of the atmosphere. The same treatment in nitrogen leads to an extinction of the luminescence. The emission process is restored when samples are kept for a sufficient time in air. To better understand this phenomenon, we have investigated the luminescence of the elementary constituents of the epoxy (resin and hardener), when heated in air and nitrogen, as well as during resin‐curing in the same atmospheres. It appears that the emission process is linked with the presence of oxygen. Although the kinetics of the luminescence can differ, depending on the nature of the sample (cured resin, resin during curing, liquid components), the emission spectra are the same during resin‐curing and upon heating of the cured resin and hardener. The emission spectrum of the base resin is different. It is concluded that the light results from a chemiluminescence process during oxidation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1899–1904, 2006
Preparation, structure and properties of nitrile–butadiene rubber–organoclay nanocomposites by reactive mixing intercalation method
Authors: Liu Lan , Jia Demin , Luo Yuanfang , Guo Baochun
Published: February 2006

The nanocomposites of nitrile–butadiene rubber (NBR) and organo‐montmorillonite modified by hexadecyltrimethyl ammonium bromide (HMMT) were prepared by the reactive mixing intercalation method in the presence of the resorcinol and hexamethylenetetramine complex (RH). The structure of the NBR–RH–HMMT nanocomposites was characterized by XRD, TEM, FTIR, determination of crosslinking density, and so on. The results showed that the d‐spacing of HMMT increased substantially with RH addition and the layers of HMMT were dispersed in rubber matrix on a nanometer scale. The mechanical properties of the NBR–RH–HMMT nanocomposites were far superior to those of NBR–HMMT composites, and the glass transition temperature of NBR–RH–HMMT nanocomposite was higher than that of NBR. The reactive mixing intercalation method by introducing RH could enhance the interface combination between the rubber and the organoclay through the interactions of RH with NBR and modified clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1905–1913, 2006
Xylan/polyvinyl alcohol blend and its performance as hydrogel
Authors: Tanodekaew Siriporn , Channasanon Somruethai , Uppanan Paweena
Published: February 2006

Xylan was first modified with maleic anhydride (MA) to obtain xylan‐MA. The derivative was then blended with polyvinyl alcohol (PVA) to generate xylan‐MA/PVA hydrogel. Xylan‐MA was prepared by reacting xylan with MA under an acidic condition. A ring opening of MA occurred, yielding ester linkages between xylan and MA, as verified by 13C‐NMR and FTIR. The effects of reaction temperature and weight ratio of xylan to MA on esterification were examined. Thermal stability of modified xylan derivatives was compared with that of pure xylan using TGA. The blends of xylan‐MA with PVA became crosslinked gel after being heated at high temperature. The influences of MA and PVA contents on strength and swelling behaviors of the gels were investigated. The cytotoxicity of the gels was also evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1914–1918, 2006
Study on volume ratio and plasticizer screening of free coating membranes composed of ethyl cellulose and chitosan
Authors: He Wen , Du Yumin , Fan Lihong
Published: February 2006

The aim of this study was to optimize the formula of free blended coating membrane of ethyl cellulose (EC) and chitosan (CS), including their suitable ratio range and the best plasticizer used. The dry films were produced by a casting/solvent evaporation method, with different volume ratio of EC and CS solution plasticized by various plasticizers, respectively. The wet films were prepared by immersing dry films in pH 6.8 phosphate buffer saline (PBS) for 24 h. The promising ratio range of EC/CS was below 20/5 or 20/6 with various plasticizer, which was determined by comparing the viscosity of the blended solutions and the morphology of the blended films. The efficiency of plasticization was evaluated by measuring glass transition temperature (Tg). All the testing plasticizers have good compatibility with EC or CS and dibutyl phthalate (DBP) have the strongest efficiency inducing the lowest Tg (39.9°C) of the film. Mechanical properties were evaluated by the ratio of tensile strength (T) to elastic modulus (E). In the wet state, the films with DBP had the highest T/E value (1.2). The results of leaching of plasticizers also verified that DBP was the most stable plasticizer in the films. The release rates of tetramethylpyrazine phosphate (TMPP) through the pellets coated with the blended films of EC/CS (20 : 6 v/v) plasticized by various plasticizers showed that the more water‐soluble the plasticizer was, the more quickly TMPP dissolved from the coated pellets, which further indicated that the water‐insoluble plasticizers (such as DBP) could be more applicable to keep the sustained or controlled release property of the blended films in wet state. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1932–1939, 2006
Effect of silicon dioxide on crystallization and melting behavior of polypropylene
Authors: Chen Minjie , Tian Guohua , Zhang Yong , Wan Chaoying , Zhang Yinxi
Published: February 2006

The crystallization and melting behavior of isotactic polypropylene (iPP) and polypropylene copolymer (co‐PP) containing silicon dioxide (SiO2) were investigated by differential scanning calorimeter (DSC). SiO2 had a heterogenous nucleating effect on iPP, leading to a moderate increase in the crystallization temperature and a decrease in the half crystallization time. However, SiO2 decreased the crystallization temperature and prolonged the half crystallization time of co‐PP. A modified Avrami theory was successfully used to well describe the early stages of nonisothermal crystallization of iPP, co‐PP, and their composites. SiO2 exhibited high nucleation activity for iPP, but showed little nucleation activity for co‐PP and even restrained nucleation. The iPP/SiO2 composite had higher activation energy of crystal growth than iPP, indicating the difficulty of crystal growth of the composite. The co‐PP/SiO2 composite had lower activation energy than co‐PP, indicating the ease of crystal growth of the composite. Crystallization rates of iPP, co‐PP, and their composites depended on the nucleation. Because of its high rate of nucleation, the iPP/SiO2 composite had higher crystallization rate than iPP. Because of its low rate of nucleation, the co‐PP/SiO2 composite had lower crystallization rate than co‐PP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1889–1898, 2006
A novel fiber‐coated strong base‐type anion exchanger with superfast kinetics. Removal and recovery of silver thiosulfate from aqueous solutions
Authors: Chanda Manas , Pillay S. Arumugom , Sarkar Amitava , Modak Jayant M.
Published: February 2006

A commercial acrylic fiber with 92% (w/w) acrylonitrile content was partially hydrolyzed converting a fraction of the nitrile (CN) groups to carboxylic acid (COOH) groups, to coat the fiber with polyethylenimine (PEI) resin, which was then crosslinked with glutaraldehyde and further quaternized with ethyl chloroacetate to produce a novel strong‐base anionic exchanger in the form of fiber. Designated as PAN(QPEI.XG)(Cl−), the fibrous sorbent was compared with a commercial bead‐form resin Amberlite IRA‐458(Cl−) in respect of sorption capacity, selectivity, and kinetics for removal of silver thiosulfate complexes from aqueous solutions. Though the saturation level of [Ag(S2O3)2]3− on PAN(QPEI.XG)(Cl−) is considerably less than that on IRA‐458(Cl−), the gel‐coated fibrous sorbent exhibits, as compared to the bead‐form sorbent, a significantly higher sorption selectivity for the silver thiosulfate complex in the presence of excess of other anions such as S2O32−, SO42−, and Cl−, and a remarkably faster rate of both sorption and stripping. The initial uptake of the sorbate by the fibrous sorbent is nearly instantaneous, reaching up to ∼80% of the saturation capacity within 10 s, as compared to only ∼12% on the bead‐form sorbent. The high initial rate of uptake fits a shell‐core kinetic model for sorption on fiber of cylindrical geometry. With 4M HCl, the stripping of the sorbed silver complex from the fibrous sorbent is clean and nearly instantaneous, while, in contrast, a much slower rate of stripping on the bead‐form sorbent leads to its fouling due to a slow decomposition of the silver thiosulfate complex in the acidic medium. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2604–2613, 2006
The relevance of immigration in the psychodynamic formulation of psychotherapy with immigrants
Authors: Halperin Silvia
Published: February 2006

The main goal of this article is to highlight the relevance of the immigration process in psychodynamic psychotherapy with immigrants. Conceived of as a general phenomenon, immigration challenges the stability of the individual's psychic structure and family organization and it has significant transgenerational implications. Its psychodynamics includes interrelated processes of mourning, discontinuity of identity and imbalance of self‐esteem. Clinically, in the psychodynamic formulation of the adult immigrant's unique experiences, behaviors and symptoms, immigration operates as a complex precipitating factor, and its three interrelated processes need to be contextualized in the patient's history, organization of identifications and defenses, central conflicts and system of beliefs and ideals. In order to capture the intersection of personal, familial and cultural meanings, the conceptual framework for the psychodynamic formulation of psychotherapy cases includes intrapsychic, interpersonal and cultural dimensions of psychic reality. The theoretical foundation of this article draws on the integration of relational psychoanalysis and social cognition. The outcome of the psychological process of immigration is considered to depend not only on the restructuring of dynamic aspects but also on non‐dynamic factors such as the immigrant's age, socioeconomic background, linguistic and cultural differences, forced or voluntary migration, and the possibility of revisiting the country of origin. Two psychotherapy case presentations illustrate the three interacting processes of the psychodynamics of immigration formulated in the context of each immigrant's history and personality from a psychodynamic framework that includes intrapsychic, interpersonal and cultural perspectives. Copyright © 2004 Whurr Publishers Ltd.
“I think of God, in order not to be aware”: defensive dissociation and the use of religious objects
Authors: LaMothe Ryan
Published: February 2006

This article explores the relation between defensive dissociation and the use of religious objects from three related directions. First, religious objects and their attributes provide an interpretative framework that generates, for the believer, an unassailable and thoroughly self‐consistent experience of agentic hate and hostility and a concomitant sense of worth, power, and efficacy, which together keep intolerable anxiety unformulated and thus outside of awareness. The unassailable religious object (e.g., crucifix or swastika) points to the collapse of potential space whereby doubt and ambiguity, which are necessary for the construction of new meaning, are eliminated. Second, I depict how unthinkable anxiety is dissociated, in part, through the formulation of omnipotent identifications and these identifications represent a collapse of potential space – a refusal to recognize likeness in difference and difference in likeness. Third, the collapse of potential space attends the breakdown of the dynamic tension between generating and submitting to experience. On the one hand, this collapse enables a compulsive, omnipotent construction of experience, a concomitant rigid subjectivity, and the foreclosure of new meaning. On the other hand, it leads to an intrapsychic, desymbolized space: an empty space from which subjectivity, meaning, and value are absent. The hidden presence of desymbolized space is indicated in the intentional construction of a depersonalized other and by the wish or plan to annihilate real and imagined others. Copyright © 2004 Whurr Publishers Ltd.
Rebirth at 40: photographs as transitional objects
Authors: Young Barbara
Published: February 2006

This article discusses how a restricted man who had lived a False Self all his life was able to educate the analyst in providing a holding environment so that he could learn to speak in his own voice, take over the control of his automatic bladder and bowel function, and gradually “own” himself for the first time. The analyst – who is also a photographer – explores the manner in which her photographs served as transitional objects to this patient and played a part in supplying the transitional space necessary for him to complete his emotional growth. The analyst expands on the interrelationship of her two careers and the important role her creativity has played in her own life. Copyright © 2004 Whurr Publishers Ltd.
The anatomy of nostalgia: from pathology to normality
Authors: Nikelly Arthur G.
Published: February 2006

This analysis traces the genesis, evolution, and function of the hitherto abandoned illness category of nostalgia and demonstrates how compelling environmental imperatives can generate a nosological construct (diagnosis) whose etiology changes according to prevailing living conditions. I show that, to a large extent, the physical symptoms of nostalgia are a function of abrupt changes in social structures and that the explanation for the nostalgic experience is influenced by cultural values and by the prevailing medical and social attitudes in various chronological periods. Nostalgia is a culturally devised label that controls and treats deviant behavior but fades when environmental circumstances restabilize. Although no longer a valid category, nostalgia helps therapists understand how to deal with homesickness, separation, and loss, and facilitates insight and coping among immigrants, sojourners, and culturally alienated persons. Copyright © 2004 Whurr Publishers Ltd.
Integrating attachment theory and neuroscience in couple therapy
Authors: Goldstein Sondra , Thau Susan
Published: February 2006

The authors integrate findings from neurophysiology, affect regulation and attachment research, and apply them to treating couples. They observe that adult styles of relating to primary attachment figures parallel the attachment styles identified in infant–caregiver relationships. They work with couples on maintaining a state of attunement, providing a secure base, recognizing non‐verbal signals of unconscious associations, and processing the emotionally charged interactions that frequently occur in the relationship. They give a clinical example that shows how an understanding of attachment styles and internal working models of relationships provides a perspective in couple therapy for dealing with the underlying needs and longings of intimate relationships. Copyright © 2004 Whurr Publishers Ltd.
Holding on and letting go: developmental anxieties in couples after the birth of a child
Authors: Berg Jenny , Jools Penny
Published: February 2006

The authors propose a theoretical sequence for the psychological development of couples from narcissistic, autistic‐contiguous and paranoid‐schizoid levels to depressive position functioning. The authors illustrate their observations with vignettes from couple therapy with a husband and wife who are dealing with the impact of a third on their fragile relationship, initially in the form of their baby, subsequently his lover and lastly the couple therapist. They show how dealing with resistance and transference enables the couple to give up a shared manic defence, grieve together and move along the developmental levels to achieve a more satisfying reality. Copyright © 2004 Whurr Publishers Ltd.
The splitting function of the dyad versus the containing function of the couple: a case of combined concurrent couple and individual therapy
Authors: Varela Yolanda De
Published: February 2006

The author describes the destructive effect of two individuals' dyadic internal object relationships on their marriage. In a combined, concurrent couple and individual therapy, she recognizes the prevalence of need‐gratifying primitive dyads and sees the destructive effect that they have on the couple's hopes for intimate relating. The therapist becomes the object of desire to which the preference for dyadic relating attaches, interprets that this reliance on dyadic functioning with each other as parent substitutes stems from lost loves of childhood, and works through with the partners until they are functioning as a mature couple of equals capable of holding, containment, interpretation of conflict and personal integration. Copyright © 2004 Whurr Publishers Ltd.
Extending fairbairn and Sutherland's socio‐intrapsychic model to assessment and treatment of a stepfamily
Authors: Bagnini Carl
Published: February 2006

The author describes an unusual adaptation of object relations family therapy tailored to the requirements of symptomatic adult children, their long‐divorced parents and their stepfamilies. He worked with the children on understanding their disturbed relationship as an identification with the pre‐divorce parental couple. He brought the divorced couple together for sessions to rework their break‐up and repair trauma to their children. He had sessions with the current stepfamily members. The design of the treatment called for moving gradually and thoroughly, back and forth, from past to present, interpersonal to intrapsychic, individual to group, and family to stepfamily. Copyright © 2004 Whurr Publishers Ltd.
Play and very young children in object relations family therapy
Authors: Scharff Jill Savege
Published: February 2006

The author encourages family therapists to include young children in their family therapy sessions so that they can achieve whole family understanding. For adult family therapists who want to learn how to include children, and individual child therapists who want to work with groups, the author presents a brief theory of play as well as an overview of object relations theory and its application to the family as a group. She provides many illustrations of the effective use of play as a mode of communication in family therapy with babies, latency‐age children and adolescents, and concludes that play and fun support learning and growth of children and their families. Copyright © 2004 Whurr Publishers Ltd.
Sephardic and Ashkenazi Jews in Israel: the reflection of social history in therapeutic processes
Authors: Strenger Carlo
Published: February 2006

An extended case study of an analytic treatment examines the difficulty of identity formation for Sephardic Jews in Israel, on the background of negative stereotypization of this group by the Ashkenazi Elites during the first decades of Israel's existence. Zionism was based on the idea that a New Jew needed to be created, as the Old Diaspora Jew was seen as weak, dejected, and self‐deprecating. The hypothesis is advanced that the Old Jew remains a split‐off part of Israeli identity, which is experienced as threatening, and that psychic wounds often found in Sephardic Jews in Israel reflect the projection of disavowed aspects of the Old Jew by Ashkenazim onto Sephardim. The case example shows how this wider social reality influences transference–countertransference interactions in analytic treatment. The patient's transference love and the therapist's complex countertransference reaction are analyzed not only as individual issues but as reflecting Israeli history and its present social and political reality. Copyright © 2004 Whurr Publishers Ltd.
Third‐wave public health? Compassion, community, and end‐of‐life care
Authors: Kellehear Allan
Published: February 2006

Clinical approaches to end‐of‐life care often extend their practise into community care, but frequently that practise has been under‐recognized and under‐theorized. A seamless practise connection with community approaches to end‐of‐life care is crucial to a total healthcare response to death and loss. One‐on‐one practises find their greatest therapeutic and aftercare support in a complementary community approach to that care. What public health models might we adapt to assist the psychological professions to support a community response to death and loss? This article reviews recent World Health Organization (WHO) work in community development, in particular the “Healthy Cities” projects. From this review, a “Compassionate Cities” framework is suggested as one fruitful way forward to address issues of prevention, health promotion, and aftercare in a holistic approach to end‐of‐life care. Copyright © 2004 Whurr Publishers Ltd.
The complexity of individuation
Authors: Semetsky Inna
Published: February 2006

This paper addresses the problematics of individuation in Deleuze and Guattari's philosophy. The concept of fold – the inside of the outside – is analyzed in terms of the relations between thought and unthought constituting the process of thinking in affects. It is suggested that thinking of this sort, called by Deleuze the supreme act of philosophy, may be considered tending towards Jungian and post‐Jungian depth psychology. The unconscious of thought is described by the archetypal dynamics of forces acting in the space of the Outside, that this paper posits as the field of collective unconscious. Analogous to Deleuzian virtual tendencies, Jungian archetypes subsist in potentia only and, as a multiplicity of relations between forces, can be expressed through cartographic microanalysis. In accord with Deleuze's method of transcendental empiricism, the unconscious, immanent, microperceptions are reterritorialized by means of mapping the archetypal field. Copyright © 2004 Whurr Publishers Ltd.
The crisis in the church: dealing with the many faces of cultural hysteria
Authors: Levine Stephen B. , Risen Candace B.
Published: February 2006

The ideas in this paper were originally presented in 2002, to three Catholic audiences, at the height of the media storm about the handling of pedophilic priests by the Church. The speakers had taken part in the evaluation of more than 100 professionals who had crossed sexual boundaries, including 30 priests. Seven clinical perspectives on the cultural hysteria are offered to stimulate the thinking of mental health professionals:

Priests are only human beings.

Most sexually inappropriate priests are not pedophiles.

The media's use of “pedophilia” is different from psychiatry's use of the term.

Catholicism is expected to offer redemption.

Bishops have a public relations conundrum.

More rigor and balance are necessary when evaluating the effects of priest abuse on victims.

Homosexuality is not the root of the problem.

Copyright © 2004 Whurr Publishers Ltd.
Vorspannung ohne Verbund und Flachdecken aus Stahlfaserbeton. Bericht aus der Praxis – Neubau der Realschule Kösching, Landkreis Eichstätt
Authors: Grad Johann , Grad Thomas , Kaßner Uwe
Published: February 2006

Dieser Werkbericht ist eine Fortsetzung der Veröffentlichung der Autoren in der Zeitschrift “Beton‐ und Stahlbetonbau”, Heft 4, 2004. Er zeigt neue Entwicklungen im Stahlbetonbau auf. Themen sind unter anderem die vorgespannte Stahlfaserdecke sowie ein Kostenvergleich mit herkömmlichen Ausführungen unter Wettbewerbsbedingungen.

Zwischenzeitlich erschienen in mehreren Fachzeitschriften Veröffentlichungen über das Thema “Vorspannungen ohne Verbund”, die sich überwiegend mit theoretischen Aspekten befaßten. Dieser Bericht möchte diese Veröffentlichungen mit Erfahrungen aus der Praxis ergänzen.
Flachdecken aus Stahlfaserbeton
Authors: Gossla Ulrich
Published: February 2006

Stahlfaserbeton ist ein bewährtes Material für elastisch gebettete Platten von Industrieböden. Seit einigen Jahren werden Industrieböden aus Stahlfaserbeton mit zusätzlicher Bewehrung als frei tragende Platten auf Pfählen ausgeführt. Ihr Tragverhalten unter Gebrauchslasten ähnelt dem einer Flachdecke. In jüngster Zeit können mit leicht verdichtbaren Betonen höhere Fasergehalte sicher verarbeitet werden.

Im Großversuch konnte gezeigt werden, daß Deckenplatten aus Stahlfaserbeton mit 100 kg/m3 Stahlfasergehalt mit den traditionellen Stahlbeton‐Flachdecken hinsichtlich Belastbarkeit und Wirtschaftlichkeit konkurrieren können. Dieser Aufsatz beschreibt die Entwicklung von frei tragenden Platten aus Stahlfaserbeton auf Basis der durchgeführten Bauteilversuche. Für die Bemessung in den Grenzzuständen der Tragfähigkeit werden Rechenansätze auf Basis der Bruchlinientheorie vorgestellt. Kriterien zur Gewährleistung der Gebrauchstauglichkeit werden gegeben.
Beton unter hohen Temperaturen – eine Frage der Tunnelsicherheit
Authors: Bergmeister Konrad
Published: February 2006

Die Sicherheit in den Tunnels wird einerseits durch das Verhalten der Benützer und andererseits durch die Konstruktion und Ausstattung bestimmt. Neben der Modellierung des Verhaltens und der Anwendung von Sicherheitstheorien in Tunnel gilt es, organisatorische und erzieherische Maßnahmen in der Planungs‐, Ausführungs‐ und Betriebsphase zu setzen. Durch die extreme Hitzeentwicklung können die Einbauten und das Tunneltragwerk beschädigt werden. Dabei kann es zu Betonabplatzungen (spalling) und zum Ablösen von Betonstücken bzw. Verankerungen kommen. In diesem Beitrag werden unterschiedliche Spritzbetone ‐experimentell unter hohen Temperaturen untersucht. Dabei zeigt sich, daß die Dichte und die Porenverteilung sowie die Zugkapazität der Betonformulierung von ausschlaggebender Bedeutung sind.
Synthesis and characterization of new biodegradable hyaluronan alkyl derivatives
Authors: Mlčochová Petra , Bystrický Slavomír , Steiner Bohumil , Machová Eva , Koóš Miroslav , Velebný Vladimír , Krčmář Martin
Published: February 2006

Several new biocompatible and degradable materials were prepared by chemical modification of sodium hyaluronate. The method of activation of hyaluronate by cyanogen bromide was used and subsequent reaction with nucleophile led to the formation of carbamate. This modification of hydroxyl groups of glycosaminoglycans preserves the carboxyl groups and retains properties of polyelectrolyte. This method affords derivatives easily and the reaction condition correlates with degree of substitution. The experimental results show the effect of reaction conditions (reaction time, ratio of reactants) and effect of substitution on biodegradability. The obtained materials were characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 74–79, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
The Ether Lipid Inositol‐C2‐PAF is a Potent Inhibitor of Cell Proliferation in HaCaT Cells
Authors: Fischer Annette , Müller Dieter , Zimmermann‐Kordmann Martin , Kleuser Burkhard , Mickeleit Michael , Laabs Stephan , Löwe Werner , Cantagrel Frédéric , Reutter Werner , Danker Kerstin
Published: February 2006

The search for specific anticancer drugs that do not interfere with DNA synthesis or influence the cytoskeleton has led to the development of modified phospholipids with antiproliferative properties. These compounds cause remodeling of the structure and function of plasma membranes. Recently, we described novel compounds, the glycosidated phospholipids, that surprisingly inhibit cell proliferation. These compounds contain α‐D‐glucose in the sn‐2 position of the glycerol backbone of phosphatidylcholine (PC) and platelet‐activating factor (PAF), which gives rise to 2‐glucophosphatidylcholine (Glc‐PC) and 1‐O‐octadecyl‐2‐O‐α‐d‐glucopyranosyl‐sn‐2‐glycero‐3‐phosphatidylcholine (Glc‐PAF), respectively. Glc‐PC and Glc‐PAF inhibit the growth of HaCaT cells at nontoxic concentrations. Here we report the introduction of myo‐inositol, in place of α‐D‐glucose, in the sn‐2 position of the glycerol backbone; this leads to two diastereomeric 1‐O‐octadecyl‐2‐O‐(2‐(myo‐inositolyl)‐ethyl)‐sn‐glycero‐3‐(R/S)‐phosphatidylcholines (Ino‐C2‐PAF). The inositol‐containing PAF enhances the antiproliferative capacity (IC50=1.8 μM) and reduces the cytotoxicity relative to Glc‐PAF (LC50=15 μM). Through biological assays, we showed that, in HaCaT cells, Ino‐C2‐PAF causes upregulation of the keratinocyte‐specific differentiation marker involucrin, increases the activity of the differentiation marker transglutaminase, and induces apoptosis at nontoxic concentrations. Ino‐C2‐PAF therefore seems to be a promising candidate for development as an antiproliferative drug for the treatment of hyperproliferative diseases of the skin.
Broad Substrate Specificity of Ketoreductases Derived from Modular Polyketide Synthases
Authors: Bali Shilpa , O'Hare Helen M. , Weissman Kira J.
Published: February 2006

Recombinant ketoreductase (KR) domains derived from antibiotic‐producing modular polyketide synthases (PKSs) have been examined as potential catalysts for the enantioselective reduction of non‐polyketide substrates. KR domains from two modular PKSs show significant activity toward alternative substrates, particularly those that incorporate cyclohexyl moieties. Through site‐directed mutagenesis of the amino acid motifs previously implicated in stereocontrol by KRs, we have identified mutants with improved activity toward such compounds. These results suggest that PKS KRs could potentially be used as biotransformation catalysts for the production of chiral alcohols.
Hybrid Peptide Hairpins Containing α‐ and ω‐Amino Acids: Conformational Analysis of Decapeptides with Unsubstituted β‐, γ‐, and δ‐Residues at Positions 3 and 8
Authors: Roy Rituparna S. , Gopi Hosahudya N. , Raghothama Srinivasarao , Karle Isabella L. , Balaram Padmanabhan
Published: February 2006

The effects of inserting unsubstituted ω‐amino acids into the strand segments of model β‐hairpin peptides was investigated by using four synthetic decapeptides, Boc‐Leu‐Val‐Xxx‐Val‐D‐Pro‐Gly‐Leu‐Xxx‐Val‐Val‐OMe: peptide 1 (Xxx=Gly), peptide 2 (Xxx=βGly=βhGly=homoglycine, β‐glycine), peptide 3 (Xxx=γAbu=γ‐aminobutyric acid), peptide 4 (Xxx=δAva=δ‐aminovaleric acid). 1H NMR studies (500 MHz, methanol) reveal several critical cross‐strand NOEs, providing evidence for β‐hairpin conformations in peptides 2–4. In peptide 3, the NMR results support the formation of the nucleating turn, however, evidence for cross‐strand registry is not detected. Single‐crystal X‐ray diffraction studies of peptide 3 reveal a β‐hairpin conformation for both molecules in the crystallographic asymmetric unit, stabilized by four cross‐strand hydrogen bonds, with the γAbu residues accommodated within the strands. The D‐Pro‐Gly segment in both molecules (A,B) adopts a type II′ β‐turn conformation. The circular dichroism spectrum for peptide 3 is characterized by a negative CD band at 229 nm, whereas for peptides 2 and 4, the negative band is centered at 225 nm, suggesting a correlation between the orientation of the amide units in the strand segments and the observed CD pattern.
Preparation and Structure of Novel Hexaazaisowurtzitane Cages
Authors: Herve Grégoire , Jacob Guy , Gallo Roger
Published: February 2006

Hexaazaisowurtzitane or cage molecules have attracted attention concerning their synthesis because hexanitrohexaazaisowurtzitane (HNIW or CL20) is presently the most powerful energetic compound. The synthesis of hexaazaisowurtzitanes was considered to be limited solely to the condensation of certain benzylamines with glyoxal. Here, we present the synthesis and characterization of seven novel non‐benzylic hexaazaisowurtzitanes, such as hexapropargylhexaazaisowurtzitane. The substituents on the six nitrogen atoms are different to those of the benzyl or substituted benzyl groups to which previous syntheses were limited. X‐ray structures are given for the hexapropargyl and hexa‐2‐thienylmethylene derivatives. Steric strains limit the synthesis with α‐substituted benzyl and allyl derivatives. The reaction mechanism and the role of the intermediate diimines are discussed. Some of the novel hexaazaisowurtzitanes are potential precursors of hexanitrohexaazaisowurtzitane.
Mechanism of Hydrolysis and Aminolysis of Homocysteine Thiolactone
Authors: Garel Jonathan , Tawfik Dan S.
Published: February 2006

Homocysteine thiolactone (tHcy) is deemed a risk factor for cardiovascular diseases and strokes, presumably because it acylates the side chain of protein lysine residues (“N‐homocysteinylation”), thereby causing protein damage and autoimmune responses. We analysed the kinetics of hydrolysis and aminolysis of tHcy and two related thiolactones (γ‐thiobutyrolactone and N‐trimethyl‐tHcy), and we have thereby described the first detailed mechanism of thiolactone aminolysis. As opposed to the previously studied (thio and oxo)esters and (oxo)lactones, aminolysis of thiolactones was found to be first order with respect to amine concentration. Anchimeric assistance by the α‐amino group of tHcy (through general acid/base catalysis) could not be detected, and the Brønsted plot (nucleophilicity versus pKa) for aminolysis yielded a slope (βnuc) value of 0.66. These data support a mechanism of aminolysis where the rate‐determining step is the formation of a zwitterionic tetrahedral intermediate. The βnuc value and steric factors dictate a regime whereby, at physiological pH values (pH 7.4), maximal reactivity of tHcy is exhibited with primary amine groups with a pKa value of 7.7; this allows the reactivity of various protein amino groups towards N‐homocysteinylation to be predicted.
Phosphoramidite Ligands in Iridium‐Catalyzed Allylic Substitution
Authors: Polet Damien , Alexakis Alexandre , Tissot‐Croset Karine , Corminboeuf Clémence , Ditrich Klaus
Published: February 2006

A new phosphoramidite ligand was used in the iridium‐catalyzed allylic substitution reaction. This permitted high regio‐ and enantioselectivities on a wide variety of substrates and nucleophiles. Because of the stereospecificity of the reaction obtained by using branched substrates, a kinetic resolution reaction was attempted. The origin of the impressive efficiency of this ligand in terms of kinetics was explored in detail, as was the role of the substituent in the ortho‐position of the amine moiety.
Structural and Magnetic Studies of the Tris(cyclopentadienyl)manganese(II) “Paddle‐Wheel” Anions [Cp3−n(MeCp)nMn]− (n=0–3, MeCp=C5H4CH3, Cp=C5H5)
Authors: Alvarez Carmen Soria , Bashall Alan , McInnes Eric J. L. , Layfield Richard A. , Mole Richard A. , McPartlin Mary , Rawson Jeremy M. , Wood Paul T. , Wright Dominic S.
Published: February 2006

The ion‐contact complexes [{(η5‐Cp)2Mn(η2:η5‐Cp)K}3]⋅0.5 THF (1⋅0.5 THF) and [{(η2‐Cp)2(η2;η5‐MeCp)MnK(thf)}]⋅2 THF (2⋅2 THF) and ion‐separated complexes [Mg(thf)6][(η2‐Cp)3Mn]2 (3), [Mg(thf)6][(η2‐Cp)(η2‐MeCp)2Mn)]2⋅0.5 THF (4⋅0.5 THF), [Mg(thf)6][(η2‐MeCp)3Mn)]2⋅0.5 THF (5⋅0.5 THF) and [Li([12]crown‐4)]5[(η‐Cp)3Mn]5 (6) (Cp=C5H5, CpMe=C5H4CH3), have been prepared and structurally characterised. The effects of varying the Cp and CpMe ligands in complexes 1–5 have been probed by variable‐temperature magnetic susceptibility measurements and EPR spectroscopic studies.
Synthesis of Fullerodendrons with an Ammonium Unit at the Focal Point and Their Cooperative Self‐Assembly on a Fluorescent Ditopic Crown Ether Receptor
Authors: Nierengarten Jean‐François , Hahn Uwe , Trabolsi Ali , Herschbach Haiko , Cardinali François , Elhabiri Mourad , Leize Emmanuelle , Van Dorsselaer Alain , Albrecht‐Gary Anne‐Marie
Published: February 2006

Dendritic branches with 1, 2, or 4 peripheral fullerene subunits and an ammonium function at the focal point have been prepared. Their ability to form self‐assembled dendritic structures with oligophenylenevinylene receptors bearing one or two crown ether moieties has been evidenced by ES‐MS studies for the first time. These supramolecular complexes are multicomponent photoactive devices in which the emission of the central receptor is dramatically quenched by the fullerene units. This new property resulting from the association of the different molecular subunits allowed detailed investigations of the self‐assembly process by means of fluorescence titrations. The binding studies have revealed positive cooperative effects for the assembly of the fullerodendrimers with the ditopic receptor. Interestingly, the stability of the supramolecular 2:1 structures increases as the size of the dendritic unit increases. This positive dendritic effect has been explained by the larger number of possible intramolecular fullerene–fullerene interactions between the two dendritic guests when the number of fullerene subunits is increased.
Self‐Assembled Structures with Liquid‐Crystalline Order in Aqueous Solution by Patterning Poly(phenylene ethynylene)s
Authors: Kim Taehyung , Arnt Lachelle , Atkins Edward , Tew Gregory N.
Published: February 2006

Facially amphiphilic (FA) phenylene ethynylene (PE) polymers that self‐assemble in aqueous solution were studied by small‐angle X‐ray diffraction (SAXD) and found to self‐assemble into bilayers with a fully extended backbone. The resulting bilayers have long‐range liquid‐crystalline order. This self‐assembly is programmed into the molecule by placing polar and nonpolar groups at precise locations so that they segregate onto opposite sides of the molecular structure. The absence of FA patterning generated an amorphous sample confirming the importance of this programmed amphiphilicity in the self‐assembly process. Facially amphiphilic patterning represents a new design criterion for supramolecular chemistry, illustrated here in the observation of molecular ordering into bilayers reminiscent of self‐assembled structures commonly found in biology, including amphiphilic β‐sheet polypeptides and phospholipid bilayers.
Supramolecular Switches Based on the Guanine–Cytosine (GC) Watson–Crick Pair: Effect of Neutral and Ionic Substituents
Authors: Fonseca Guerra Célia , van der Wijst Tushar , Bickelhaupt F. Matthias
Published: February 2006

We have theoretically analyzed Watson–Crick guanine–cytosine (GC) base pairs in which purine‐C8 and/or pyrimidine‐C6 positions carry a substituent X = NH−, NH2, NH3+(N series), O−, OH, or OH2+(O series), using the generalized gradient approximation (GGA) of density functional theory at the BP86/TZ2P level. The purpose is to study the effects on structure and hydrogen‐bond strength if X= H is substituted by an anionic, neutral, or cationic substituent. We found that replacing X = H by a neutral substituent has relatively small effects. Introducing a charged substituent, on the other hand, led to substantial and characteristic changes in hydrogen‐bond lengths, strengths, and hydrogen‐bonding mechanism. In general, introducing an anionic substituent reduces the hydrogen‐bond‐donating and increases the hydrogen‐bond‐accepting capabilities of a DNA base, and vice versa for a cationic substituent. Thus, along both the N and O series of substituents, the geometric shape and bond strength of our DNA base pair can be chemically switched between three states, thus yielding a chemically controlled supramolecular switch. Interestingly, the orbital‐interaction component in some of these hydrogen bonds was found to contribute to more than 49 % of the attractive interactions and is thus virtually equal in magnitude to the electrostatic component, which provides the other (somewhat less than) 51 % of the attraction.
The Interplay of Inverted Redox Potentials and Aromaticity in the Oxidized States of New π‐Electron Donors: 9‐(1,3‐Dithiol‐2‐ylidene)fluorene and 9‐(1,3‐Dithiol‐2‐ylidene)thioxanthene Derivatives
Authors: Amriou Samia , Wang Changsheng , Batsanov Andrei S. , Bryce Martin R. , Perepichka Dmitrii F. , Ortí Enrique , Viruela Rafael , Vidal‐Gancedo José , Rovira Concepció
Published: February 2006

Derivatives of 9‐(1,3‐dithiol‐2‐ylidene)fluorene (9) and 9‐(1,3‐dithiol‐2‐ylidene)thioxanthene (10) have been synthesised using Horner–Wadsworth–Emmons reactions of (1,3‐dithiol‐2‐yl)phosphonate reagents with fluorenone and thioxanthen‐9‐one. X‐ray crystallography, solution electrochemistry, optical spectroscopy, spectroelectrochemistry and simultaneous electrochemistry and electron paramagnetic resonance (SEEPR), combined with theoretical calculations performed at the B3P86/6‐31G** level, elucidate the interplay of the electronic and structural properties in these molecules. These compounds are strong two‐electron donors, and the oxidation potentials depend on the electronic structure of the oxidised state. Two, single‐electron oxidations (${E{{{\rm ox}\hfill \atop 1\hfill}}}$<${E{{{\rm ox}\hfill \atop 2\hfill}}}$) were observed for 9‐(1,3‐dithiol‐2‐ylidene)fluorene systems (9). In contrast, derivatives of 9‐(1,3‐dithiol‐2‐ylidene)thioxanthene (10) display the unusual phenomenon of inverted potentials (${E{{{\rm ox}\hfill \atop 1\hfill}}}$>${E{{{\rm ox}\hfill \atop 2\hfill}}}$) resulting in a single, two‐electron oxidation process. The latter is due to the aromatic structure of the thioxanthenium cation (formed on the loss of a second electron), which stabilises the dication state (102+) compared with the radical cation. This contrasts with the nonaromatic structure of the fluorenium cation of system 9. The two‐electron oxidation wave in the thioxanthene derivatives is split into two separate one‐electron waves in the corresponding sulfoxide and sulfone derivatives 27–29 owing to destabilisation of the dication state.
Shape and Spin State in Four‐Coordinate Transition‐Metal Complexes: The Case of the d6 Configuration
Authors: Cirera Jordi , Ruiz Eliseo , Alvarez Santiago
Published: February 2006

Generalized polyhedral interconversion coordinates are defined within the framework of Avnir's continuous shape measures. The application of such interconversion coordinates to the study of the potential energy surfaces that define the stereochemical choice in four‐coordinate transition metal complexes with different spin states is presented, and the correlation between potential energy curves and distribution of experimental structures along the tetrahedron to square interconversion path is shown for the case of the d6 transition‐metal complexes.
Cover Picture: A Competitive Molecular Recognition Study: Syntheses and Analysis of Supramolecular Assemblies of 3,5‐Dihydroxybenzoic Acid and Its Bromo Derivative with Some N‐Donor Compounds (Chem. Eur. J. 6/2006)
Authors: Varughese Sunil , Pedireddi Venkateswara Rao
Published: February 2006

Synthesis of molecular architectures through molecular recognition, with the proper choice of appropriate functional groups, demonstrates the elegancy of noncovalent synthesis to yield molecular ladders, rosettes, tubular structures, and so forth. In this context, 3,5‐dihydroxybenzoic acid and its bromo derivative have been found to yield molecular ladders upon co‐crystallization with some N‐donor compounds. More details of these fascinating supramolecular assemblies are described by V. R. Pedireddi and S. Varughese on page 1597 ff.
Reverse Hydrogen Spillover in Supported Subnanosize Clusters of the Metals of Groups 8 to 11. A Computational Model Study.
Authors: Vayssilov Georgi N. , Roesch Notker
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ab initio Studies of Structure and Magnetic Structure in YCo3H2.
Authors: Cui X. Y. , Liu J. , Morrison I. , Ross D. K.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Theoretical Modeling of Hydrogen Storage Materials: Prediction of Structure, Chemical Bond Character, and High‐Pressure Behavior
Authors: Vajeeston P. , Ravindran P. , Kjekshus A. , Fjellvaag H.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Crystal Structures, Raman Spectroscopy, and Magnetic Properties of Ba7.5Al13Si29 and Eu0.27Ba7.22Al13Si29.
Authors: Condron Cathie L. , Porter Rhiannon , Guo Ting , Kauzlarich Susan M.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ca6Cu2Sn7: Novel 3D Open Framework with Unusual Sn4 Tetramers.
Authors: Sun Zhong‐Ming , Xia Sheng‐Qing , Huang Yi‐Zhi , Wu Li‐Ming , Mao Jiang‐Gao
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Luminescent Lanthanide Selenites and Tellurites Decorated by MoO4 Tetrahedra or MoO6 Octahedra: Nd2MoSe2O10, Gd2MoSe3O12, La2MoTe3O12, and Nd2MoTe3O12.
Authors: Shen Yue‐Ling , Jiang Hai‐Long , Xu Jian , Mao Jiang‐Gao , Cheah Kok Wai
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Characterization and ab initio XRPD Structure Determination of a Novel Silicate with Vierer Single Chains: The Crystal Structure of NaYSi2O6.
Authors: Toebbens Daniel M. , Kahlenberg Volker , Kaindl Reinhard
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structural and Magnetic Properties of the Solid Solution (0 ≤ x ≤ 1) YMn1‐x (Cu3/4Mo1/4)xO3.
Authors: Malo Sylvie , Maignan Antoine , Marinel Sylvain , Hervieu Maryvonne , Poeppelmeier Kenneth R. , Raveau Bernard
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Polar Open‐Framework Structure, Optical Properties, and Electron Paramagnetic Resonance of the Mixed‐Metal Uranyl Phosphate Cs2 [UO2(VO2)2(PO4)2] ×0.59H2O.
Authors: Shvareva Tatiana Y. , Beitz James V. , Duin Evert C. , Albrecht‐Schmitt Thomas E.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
High‐Temperature Polymorphism in Metastable BiMnO3.
Authors: Montanari Erica , Calestani Gianluca , Migliori Andrea , Dapiaggi Monica , Bolzoni Fulvio , Cabassi Riccardo , Gilioli Edmondo
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
First Structural Characterization of a Protactinium(V) Single Oxo Bond in Aqueous Media.
Authors: Le Naour Claire , Trubert Didier , Di Giandomenico Maria V. , Fillaux Clara , Den Auwer Christophe , Moisy Philippe , Hennig Christoph
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Supported Superparamagnetic Pd/Co Alloy Nanoparticles Prepared from a Silica/Cyanogel Co‐Gel.
Authors: Vondrova Martina , Klimczuk Tomasz , Miller V. L. , Kirby Brent W. , Yao Nan , Cava R. J. , Bocarsly Andrew B.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.