bluuebunny/crossref_metadata_2025 huggingface dataset:
Orthoesters versus 2‐O‐Acyl Glycosides as Glycosyl Donors: Theorectical and Experimental Studies
Authors: Fraser‐Reid Bert , Grimme Stefan , Piacenza Manuel , Mach Mateuz , Schlueter Urs
Published: October 2003

n‐Pentenyl orthoesters (NPOEs) undergo routine acid catalyzed rearrangement into 2‐O‐acyl n‐pentenyl glycosides (NPGs). The reactant and product can both function as glycosyl donors affording 1,2‐trans linked glycosides predominantly. However, both donors differ in their rates of reactions, the yields they produce, and the nature of their byproducts, indicating that the NPOE/NPG pair may not be reacting through the same intermediates. We have therefore applied quantum chemical calculations using DFT methods and MP second order perturbation theory to learn more about orthoesters and their 2‐O‐acyl glycosidic counterparts. The calculations show that in the case of a manno NPG and NPOE pair, each donor goes initially to a different cationic intermediate. Thus, the former goes to a high‐energy oxocarbenium ion before descending to a trioxolenium ion in which the charge is distributed over the pyrano ring oxygen, as well as the carbonyl and ether oxygen atoms of the putative C2 ester. On the other hand, ionization of the NPOE produces a dioxolenium ion lying slightly above the more stable trioxolenium counterpart. For the gluco pair, the NPG also goes to a very high‐energy oxocarbenium ion, which also descends to a trioxolenium ion. However, unlike the manno analogue, the gluco NPOE does not give a dioxolenium ion; indeed, the dioxolenium is not energetically distinguishable from the trioxolenium counterpart. The theoretical observations have been tested experimentally. Thus, it was found that with manno derivatives, the orthoester is a more reactive donor than the corresponding NPG donor, whereas, for gluco derivatives, there is no advantage to using one over the other, unless one resorts to carefully selected promoters.
Rigid, Conjugated, Fluoresceinated Thymidine Triphosphates: Syntheses and Polymerase Mediated Incorporation into DNA Analogues
Authors: Thoresen Lars H. , Jiao Guan‐Sheng , Haaland Wade C. , Metzker Michael L. , Burgess Kevin
Published: October 2003

Syntheses of a unique set of energy transfer dye labeled nucleoside triphosphates, compounds 1–3, are described. Attempts to prepare these compounds were only successful if the triphosphorylation reaction was performed before coupling the dye to the nucleobase, and not the other way around. Compounds were prepared as both the 2′‐deoxy (a) and 2′,3′‐dideoxy‐ (b) forms. They feature progressively longer rigid conjugated linkers connecting the nucleobase and the hydroxyxanthone moiety. UV spectra of the parent nucleosides 12–14 show that as the length of the linker increases so does the absorption of the donor in the 320–330 nm region, but with relatively little red‐shift of the maxima. Fluorescence spectra of the same compounds show that radiation in the 320–330 nm region results in predominant emission from the fluorescein. When the linker is irradiated at 320 nm, the only significant emission observed corresponds to the hydroxyxanthone part of the molecules at 520 nm; this corresponds to an effective Stokes' shift of 200 nm. As the absorption at 320–330 nm by the linker increases with length, so does the intensity of the fluorescein emission. A gel assay was used to gauge relative incorporation efficiencies of compounds 1–3, dTTP, ddTTP, and 6‐TAMRA‐ddTTP. Throughout, the thermostable polymerase TaqFS was used, as it is the one most widely applied in high throughput DNA sequencing. This assay showed that only compounds 3 were incorporated efficiently; these have the longest linkers. Of these, the 2′‐deoxy nucleoside 3 a was incorporated and did not prevent the polymerase from extending the chain further. The 2′,3′‐dideoxy nucleoside 3 b was incorporated only about 430 times less efficiently than ddTTP under the same conditions, and caused chain termination. The implications of these studies on modified sequencing protocols are discussed.
Bonding of Multiple Noble‐Gas Atoms to CUO in Solid Neon: CUO(Ng)n (Ng=Ar, Kr, Xe; n=1, 2, 3, 4) Complexes and the Singlet–Triplet Crossover Point
Authors: Liang Binyong , Andrews Lester , Li Jun , Bursten Bruce E.
Published: October 2003

Laser‐ablated U atoms co‐deposited with CO in excess neon produce the novel CUO molecule, which forms distinct Ng complexes (Ng=Ar, Kr, Xe) with the heavier noble gases. The CUO(Ng) complexes are identified through CO isotopic and Ng reagent substitution and comparison to results of DFT frequency calculations. The U–C and U–O stretching frequencies of CUO(Ng) complexes are slightly red‐shifted from neon matrix 1Σ+ CUO values, which indicates a 1A′ ground state for the CUO(Ng) complexes. The CUO(Ng)2 complexes in excess neon are likewise singlet molecules. However, the CUO(Ng)3 and CUO(Ng)4 complexes exhibit very different stretching frequencies and isotopic behaviors that are similar to those of CUO(Ar)n in a pure argon matrix, which has a 3A″ ground state based on DFT vibrational frequency calculations. This work suggests a coordination sphere model in which CUO in solid neon is initially solvated by four or more Ne atoms. Up to four heavier Ng atoms successively displace the Ne atoms leading ultimately to CUO(Ng)4 complexes. The major changes in the CUO stretching frequencies from CUO(Ng)2 to CUO(Ng)3 provides evidence for the crossover from a singlet ground state to a triplet ground state.
Reaction of Alkyn‐1‐yl(diorganyl)silanes with 1‐Boraadamantane: Si‐H‐B Bridges Confirmed by the Molecular Structure in the Solid State and in Solution
Authors: Wrackmeyer Bernd , Milius Wolfgang , Tok Oleg L.
Published: October 2003

1‐Boraadamantane 1 was treated with alkyn‐1‐ylsilanes 2 containing one or two SiH functions. Under mild conditions, the reaction gave 4‐methylene‐3‐borahomoadamantane derivatives 4 quantitatively and selectively by 1,1‐organoboration. An electron deficient Si‐H‐B bridge was present in the product. The analogous reaction of 1 with an alkyn‐1‐yl‐disilane 3 gave the corresponding alkene derivative 5, however, without the Si‐H‐B bridge. Evidence for the Si‐H‐B bridge in 4 was given by IR data, an extensive set of NMR spectroscopical data (1H, 11B, 13C, 29Si NMR) including various unusual isotope effects on chemical shifts and coupling constants, as well as from the molecular structure of one example, 4 e, in the solid state. The precursor of 4 e, alkyne 2 e, Ph2Si(H)CCSi(H)Ph2, was also studied by X‐ray analysis.
Synthesis and Characterization of New Biphenolate and Binaphtholate Rare‐Earth‐Metal Amido Complexes: Catalysts for Asymmetric Olefin Hydroamination/Cyclization
Authors: Gribkov Denis V. , Hultzsch Kai C. , Hampel Frank
Published: October 2003

Monomeric diolate amido yttrium complexes [Y{diolate}{N(SiHMe2)2}(thf)2] can be prepared in good yield by treating [Y{N(SiHMe2)2}3(thf)2] with either 3,3′‐di‐tert‐butyl‐5,5′,6,6′‐tetramethyl‐1,1′‐biphenyl‐2,2′‐diol (H2(Biphen)), 3,3′‐bis(2,4,6‐triisopropylphenyl)‐2,2′‐dihydroxy‐1,1′‐dinaphthyl (H2(Trip2BINO)) or 3,3′‐bis(2,6‐diisopropylphenyl)‐2,2′‐dihydroxy‐1,1′‐dinaphthyl (H2(Dip2BINO)) in racemic and enantiopure form. The racemic complex [Y(biphen){N(SiHMe2)2}(thf)2] dimerizes upon heating to give the heterochiral complex (R,S)‐[Y(biphen){N(SiHMe2)2}(thf)]2. The corresponding dimeric heterochiral lanthanum complex was the sole product in the reaction of H2(Biphen) with [La{N(SiHMe2)2}3(thf)2]. Single‐crystal X‐ray diffraction of both dimeric complexes revealed that the two Ln(biphen){N(SiHMe2)2}(thf) fragments are connected through bridging phenolate groups of the biphenolate ligands. The two different phenolate groups undergo an intramolecular exchange process in solution leading to their equivalence on the NMR timescale. All complexes were active catalysts for the hydroamination/cyclization of aminoalkynes and aminoalkenes at elevated temperature, with [Y((R)‐dip2bino){N(SiHMe2)2}(thf)2] being the most active one giving enantioselectivities of up to 57 % ee. Kinetic resolution of 2‐aminohex‐5‐ene proceeded with this catalyst with 6.4:1 trans selectivity to give 2,5‐dimethylpyrrolidine with a krel of 2.6.
Molecular Energy and Electron Transfer Assemblies Made of Self‐Organized Lipid‐Porphyrin Bilayer Vesicles
Authors: Komatsu Teruyuki , Moritake Miho , Tsuchida Eishun
Published: October 2003

Novel molecular energy and electron transfer assemblies in vesicular form, which are made of self‐organized amphiphilic porphyrins bearing phospholipid‐like substituents (lipid‐porphyrins), have been photochemically characterized. Tetraphenylporphyrin (TPP) derivatives with four dialkylphosphocholine groups [free‐base (1 a), Zn2+ complex (1 b), and Fe3+ complex (1 c)] are spontaneously associated in water to form spherical unilamellar vesicles with a diameter of 100–150 nm. Exciton calculations based on the bilayered sheet model of 1 b, which has a porphyrin packing similar to that seen in the triclinic unit cell of the Zn2+TPP crystals, reproduced the Soret band bathochromic shift appearing in the aqueous solution of 1 b well. The UV/Vis absorption spectrum of the 1 a/1 b hybrid vesicles (molar ratio: 1/1) showed no electronic interaction between the two porphyrin chromophores in the ground state, but efficient intermolecular singlet–singlet energy transfer took place from the excited 1 b donors to the 1 a acceptor within the vesicle. Near‐field scanning optical microspectroscopy of the 1 a/1 b vesicles on a graphite surface also showed only free‐base porphyrin fluorescence. The efficiency of the energy transfer was 0.81 and the rate constant was 3.1×109 s−1. On the other hand, protoporphyrin IX bearing two alkylphosphocholine propionates (2) was incorporated into the 1 a or 1 c bilayer vesicles (ca. 100 nm ϕ, molar ratio: 1 a/2 or 1 c/2=10). The UV/Vis absorption spectrum showed that 2 was successfully anchored into the fluid alkylene region of the membrane without stacking. Photoirradiation (λex: 390 nm) of the 1 c/2 vesicles in the presence of triethanolamine led a vectorial electron transfer from the outer aqueous phase to the membrane center, which allowed reduction of the ferric ion of the Fe3+TPP platform.
The First Structural Characterisation of a Group 2 Metal Alkylperoxide Complex: Comments on the Cleavage of Dioxygen by Magnesium Alkyl Complexes
Authors: Bailey Philip J. , Coxall Robert A. , Dick Caroline M. , Fabre Sylvie , Henderson Louise C. , Herber Christian , Liddle Stephen T. , Loroño‐González Daniel , Parkin Andrew , Parsons Simon
Published: October 2003

A new high‐yield synthesis of [(PhCH2)2Mg(thf)2] and [{(PhCH2)CH3Mg(thf)}2] via benzylpotassium has allowed a simple entry into benzylmagnesium coordination chemistry. The syntheses and X‐ray crystal structures of both [(η2‐Me2NCH2CH2NMe2)Mg(CH2Ph)2] and [η2‐HC{C(CH3)NAr′}2Mg(CH2Ph)(thf)] (Ar′=2,6‐diisopropylphenyl) are reported. The latter β‐diketiminate complex reacts with dioxygen to provide a 1:2 mixture of dimeric benzylperoxo and benzyloxo complexes. The benzylperoxo complex [{η2‐HC{C(CH3)NAr′}2Mg(μ‐η2:η1‐OOCH2Ph)}2] is the first example of a structurally characterised Group 2 metal–alkylperoxo complex and contains the benzylperoxo ligands in an unusual μ‐η2:η1‐coordination mode, linking the two five‐coordinate magnesium centres. The OO separation in the benzylperoxo ligands is 1.44(2) Å. Reaction of the benzylperoxo/benzyloxo complex mixture with further [η2‐HC{C(CH3)NAr′}2Mg(CH2Ph)(thf)] results in complete conversion of the benzylperoxo species into the benzyloxo complex. This reaction, therefore, establishes the cleavage of dioxygen by this system as a two‐step process that involves initial oxygen insertion into the MgCH2Ph bond followed by OO/MgC σ‐bond metathesis of the resulting benzylperoxo ligand with a second MgCH2Ph bond. The formation of a 1:2 mixture of the benzylperoxo and benzyloxo species indicates that the rate of the insertion is faster than that of the metathesis, and this is shown to be consistent with a radical mechanism for the insertion process.
Complementary Nucleobase Interaction Enhances Peptide–Peptide Recognition and Self‐Replicating Catalysis
Authors: Matsumura Sachiko , Takahashi Tsuyoshi , Ueno Akihiko , Mihara Hisakazu
Published: October 2003

The availability of the complementary interaction of nucleobases for influencing the formation of peptide architectures was explored. Nucleobases were incorporated as additional recognition elements in coiled‐coil peptides by employing nucleobase amino acids (NBAs), which are artificialL‐α‐aminoγ‐nucleobase‐butyric acids. The effect of the base‐pair interaction on intermolecular recognition between peptides was evaluated through a self‐replication reaction. The self‐replication reactions of the peptides with complementary base pairs such as thymine–adenine or guanine–cytosine at theg–g′ heptad positions were accelerated in comparison with those of the peptides with mismatched base pairs or without nucleobases. However, thymine–adenine pairs at thee–e′ positions did not enhance the self‐replication. In the presence of a denaturant, the enhancement effects of complementary base pairs on the reaction disappeared. Thermal denaturation studies showed that the thymine–adenine pairs contributed to stabilization of the coiled‐coil structure and that the pairs at theg–g′ positions were more effective than those at thee–e′ positions. The peptide–peptide interaction was reinforced by complementary nucleobase interactions appropriately arranged in the peptide structure; these led to acceleration of the self‐replication reactions.
Wasser, Wäsche, Umwelt: Alles sauber?
Authors: Glathe Stefanie , Schermer Detlef
Published: October 2003

Die zeit‐ und kräfteraubende große Wäsche am Fluss hat sich heute in Waschmaschinen mit Mikrochip‐Prozessoren zu einem hochtechnisierten Vorgang entwickelt. Trotzdem sind die beteiligten Faktoren Zeit, Chemie, Mechanik und Temperatur dieselben geblieben, allein ihre Gewichtung hat sich verschoben. Die Optimierung der Wirksamkeit der Waschmittel und des Waschprozesses muss möglichen Gewässer‐ und anderen Umweltbelastungen gegenübergestellt werden. Der Artikel beleuchtet Lösungsansätze für die Balance zwischen Produktleistung und Ökologie des Waschens am Beispiel der wichtigsten Waschmittelinhaltsstoffe.
Apoptose als Therapie
Authors: Feil Sylvia
Published: October 2003

Wird eine Pigment bildende Zelle durch einen Sonnenbrand geschädigt, kann sich daraus über eine Spanne von mehreren Jahrzehnten ein Tumor entwickeln. Dabei entzieht sich das Melanom — der schwarze Hautkrebs — sehr nachhaltig der Immunabwehr, deren wichtiges Werkzeug die Apoptose ist. Hier wollen Dermatologen und Molekularbiologen von der Freien Universität Berlin ansetzen.
Roaming times of multi‐wireless systems for software defined radio
Authors: Wei YingRao , Elhakeem A. K.
Published: October 2003

In this paper, we evaluate the roaming time performance for a reconfigurable multi‐mode mobile station (MS) that experiences possible transition from one kind of wireless system standard to another. In future software defined radio systems (SDR) (IEEE Commun Mag 2000; 138–143, IEE 1998; 1–6, IEEE 1999; 1212–1216, IEEE Commun Mag 1995; 33), reconfigurability of the MS is achieved by downloading the system configuration software code over the wireless channel. For evaluation of the roaming times, a generalized state diagram of the multi‐mode MS is presented. We focus on evaluating the times for sensing the universal pilot channel, classic base station pilot channel, association and connection establishment signaling are included. We investigate the effects of packet successful transmission probability over the wireless channel. We also consider the effects of the system resource blocking probability, MS resource blocking probability, and signaling bit rate over the universal base station channel for different cases and design scenarios. Such evaluations are important for prior design of SDR mobile terminal and universal base station in global roaming situations. We include some analysis results from many obtained. These show the feasibility of wireless software download, and switching between different wireless standard as the mobile station roams. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of resequencing in downloads
Authors: Nebat Yoav , Sidi Moshe
Published: October 2003

Recent studies indicate that out‐of‐order arrival of data packets during downloads of resources is not pathological network behaviour (ACM/IEEE Trans. Networking 1999; 7(6):789). Though this situation is most intuitive when packets of the same resource arrive in parallel from several sources, it turns out that this phenomenon may also occur in the single source scenario. Knowledge regarding the expected reordering needed is important both for being able to decide on the size of the resequencing buffer needed, and to estimate the burstiness in arrival of data to the application. In this study we present a method to calculate the resequencing buffer occupancy probabilities for the single source scenario, and a study of the resequencing buffer occupancy for the two source scenario, where arrival from each of the sources is in order. Copyright © 2003 John Wiley & Sons, Ltd.
An adaptive quality of service channel borrowing algorithm for cellular networks
Authors: Habib Ibrahim , Sherif Mahmoud , Naghshineh Mahmoud , Kermani Parviz
Published: October 2003

A multimedia call consists of three main sub‐streams (i.e. video, audio and data) each with its own distinct quality of service (QoS) requirements (e.g. packet loss rate, delay tolerance, and jitter). These requirements constitute a specific fixed QoS level. In contrast to static approaches, we propose an adaptive QoS platform in which each sub‐stream declares a preset range of acceptable QoS levels (e.g. maximum, acceptable, minimum) instead of just a single level. This range of QoS levels is pre‐defined in a user‐defined profile (UDP). In this paper, we propose a channel borrowing algorithm based on such adaptive QoS platform. In our proposed algorithm, an acceptor cell that has used all its channels can borrow from any neighbouring (donor) cell as long as this donor cell has some channels available after satisfying a minimum QoS (minQ) level defined in the UDP. A donor cell that is assigning QoS levels (to calls under its coverage) higher than the minQ levels will declare those channels as available for borrowing by other acceptor cells. The criteria for choosing the free channel include not only the number of free channels, but also the QoS levels in the donor cell. The criteria are also extended to include the effect of channel locking on the number of free channels, and the QoS levels on the locked cells. The algorithm is not triggered unless it does not cause any call dropping in either the donor cell, or the cells affected by call blocking. In the meantime, the call blocking rate is significantly decreased while the offered load increases. Copyright © 2003 John Wiley & Sons, Ltd.
(Alkyl)(monocyclopentadienyl)niobium and ‐tantalum Complexes in Insertion Processes
Authors: Gómez Manuel
Published: October 2003

Alkyl high‐valent early transition metal compounds are important organometallic species, particularly because their reactions with unsaturated molecules, such as carbon monoxide and organic isocyanides, are relevant to several industrial stoichiometric and catalytic processes. Recently, we have reported several studies concerning (alkyl)(monocyclopentadienyl) derivatives of group‐5 metals, including both synthetic aspects and chemical behaviour in insertion reactions. This Microreview is an account of this work, covering syntheses, structure, spectroscopic, and reactivity details that have been reported by us together with the most significant contributions from other authors. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
PdII, ZnII and AgI Complexes of Tetrakis(N‐7‐azaindolyl)benzene: Variation of Bonding Modes, Extended Structures and Luminescence
Authors: Song Datong , Wang Suning
Published: October 2003

PdII, AgI and ZnII complexes of tetrakis(7‐azaindolyl)benzene (ttab), [(PdCl2)2(ttab)] (1), [(ZnCl2)2(ttab)] (2), [Ag(NO3)]2(ttab) (3a) and [Ag(NO3)(DMSO)]2(ttab) (3b) were synthesized and fully characterized by NMR spectroscopy, single‐crystal X‐ray diffraction and elemental analyses. The ttab ligand in these complexes displays two different bonding modes. In the PdII and ZnII complexes, the ttab ligand chelates to the metal center via two ortho 7‐azaindolyl groups (the ortho mode). In contrast, in the AgI complex, it chelates to the AgI ion via two meta 7‐azaindolyl groups (the meta mode). In the solid state, molecules of 1 and 2 form grid‐like extended structures that host solvent molecules such as DMSO and CH2Cl2. Compound 3a appears to be a coordination polymer and can be converted into compound 3b when dissolved in DMSO. A hydrogen bonded complex [Zn(O2CCF3)2(H2O)2](ttab) (4), which displays an unusual hydrogen bonded helical chain structure in the solid state, was also characterized. Except for compound 1, these new compounds all emit blue light when irradiated by UV radiation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Room‐Temperature Route to Bismuth Nanotube Arrays
Authors: Yang Baojun , Li Cun , Hu Hanmei , Yang Xiaogang , Li Qiaowei , Qian Yitai
Published: October 2003

A room‐temperature aqueous‐chemical route has been developed to synthesize a high proportion (above 80%) of bamboo‐raft‐like bismuth nanotube arrays using bismuth chloride and metallic zinc powder as reagents. The prepared Bi nanotubes have uniform diameters of approximately 3−5 nm and lengths from several hundred nanometers to several micrometers. HRTEM observations show that the axial direction of the prepared nanotubes is along the normal direction of the (012) lattice planes of the rhombohedral bismuth. The possible formation mechanism is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Oxosulfido Complexes of Platinum — (Ph3P)2Pt(S2O) and (Ph3P)4Pt2(μ‐S)(μ‐SO) — Their Formation and Properties
Authors: Ishii Akihiko , Murata Masami , Oshida Hideaki , Matsumoto Kimiyo , Nakayama Juzo
Published: October 2003

The platinum S2O complex [(Ph3P)2Pt(S2O)] (10) was obtained by S2O transfer reactions from tetrathiolane 2‐oxide (8), tetrathiolane 2,3‐dioxide (5), and pentathiane 3‐oxide (6) to [(C2H4)Pt(PPh3)2] (4). The S2O complex 10 further reacts with 4 to give a novel binuclear platinum complex 16, which is found to be a source of several platinum SnOm complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
2D Chiral Uranyl(VI) Coordination Polymers with Second‐Harmonic Generation Response and Ferroelectric Properties
Authors: Xie Yong‐Rong , Zhao Hong , Wang Xi‐Sen , Qu Zhi‐Rong , Xiong Ren‐Gen , Xue Xiang , Xue Ziling , You Xiao‐Zeng
Published: October 2003

The in situ hydrothermal reactions of UO2(NO3)2 with 1‐oxo‐4‐cyanopyridine (ocpy) and ethyl (S)‐lactate (e‐la) afforded two unprecedented chiral 2D neutral luminescent square grids, uranyl‐bis(1‐oxo‐4‐pyridylcarboxylate) UO2(opyca)2 (1) and homochiral uranyl‐bis[(S)‐lactate] (2). Their solid‐state structures, preliminary optical and photoluminescent properties are reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The outcomes of psychotherapy with adolescents: A practitioner‐friendly research review
Authors: Roberts Michael C. , Lazicki‐Puddy Tammy A. , Puddy Richard W. , Johnson Rebecca J.
Published: October 2003

This article summarizes the outcome findings of psychotherapy with adolescents through an examination of the research literature. In this problem‐focused review of the research literature, we consider adolescent treatment of anxiety disorders, depression, eating disorders, disruptive behavior disorders, multiple problems of adolescence, and health risk behaviors. The evidence base for the effectiveness of various psychotherapies for adolescents is mixed. Psychotherapy in general has been a ripe field in which unsupported approaches have grown, and this is certainly true for psychotherapeutic interventions with adolescents. Nonetheless, there is a growing body of evidence to support various types of interventions as effective for different presenting problems. Researchers and clinicians need to recognize the complexity of the diverse characteristics of adolescents, including variations of culture, race, ethnicity, gender, class, physical disability, family definitions and constellation, and sexual orientation. These require sensitivity, responsiveness, and competence by the therapist, but clinical research has not fully examined these considerations. © 2003 Wiley Periodicals, Inc. J Clin Psychol/In Session.
Transforming psychotherapy in order to succeed with adolescent boys: Male‐friendly practices
Authors: Kiselica Mark S.
Published: October 2003

The purpose of this article is to describe a “male‐friendly” therapeutic process with troubled adolescent boys. A male‐friendly process is one in which the therapist employs a wide variety of strategies and activities that are likely to appeal to male youth and that facilitate the establishment and maintenance of rapport. The nuances of practicing a male‐friendly approach are highlighted and then applied in a case study of psychotherapy with a depressed adolescent boy. The implications of this approach for redefining professional conceptions about boundaries in the client–therapist relationship and reexamining inaccurate stereotypes about the emotional lives of boys are discussed. © 2003 Wiley Periodicals, Inc. J Clin Psychol/In Session.
Zinc partitions insulin‐like growth factors (IGFs) from soluble IGF binding protein (IGFBP)‐5 to the cell surface receptors of BC3H‐1 muscle cells
Authors: McCusker Robert H. , Novakofski Jan
Published: October 2003

Zinc (Zn2+) is a multifunctional micronutrient. The list of functions for this micronutrient expanded with the recent discovery that Zn2+ retains insulin‐like growth factors binding proteins (IGFBPs) on the surface of cultured cells, lowers the affinity of cell‐associated IGFBPs, and increases the affinity of the cell surface insulin‐like growth factor (IGF)‐type 1 receptor (IGF‐1R). However, currently there is no information concerning the effect of Zn2+ on soluble IGFBPs. In the current study, the soluble IGFBP‐5 secreted by BC3H‐1 cells is shown to bind approximately 50% more [125I]‐IGF‐II than [125I]‐IGF‐I at pH 7.4. Zn2+ is shown to depress the binding of both IGF‐I and IGF‐II to soluble secreted IGFBP‐5; [125I]‐IGF‐I binding is affected more so than [125I]‐IGF‐II binding. Zn2+ acts by lowering the affinity (Ka) of IGFBP‐5 for the IGFs. Scatchard plots are non‐linear indicating the presence of high and low affinity binding sites; Zn2+ affects only binding to the high affinity site. In contrast, Zn2+ increases the affinity by which either [125I]‐IGF‐I or [125I]‐R3‐IGF‐I binds to the IGF‐1R, but depresses [125I]‐IGF‐II binding to the IGF‐type 2 receptor (IGF‐2R) on BC3H‐1 cells. By depressing the association of the IGFs with soluble IGFBPs, Zn2+ is shown to repartition either [125I]‐IGF‐I or [125I]‐IGF‐II from soluble IGFBP‐5 onto cell surface IGF receptors. Zn2+ was active at physiological doses depressing IGF binding to IGFBP‐5 and the IGF‐2R at 15–20 μM. Hence, a novel mechanism is further characterized by which the trace micronutrient Zn2+ could regulate IGF activity. J. Cell. Physiol. 197: 388–399, 2003© 2003 Wiley‐Liss, Inc.
Grb10 adapter protein as regulator of insulin‐like growth factor receptor signaling
Authors: Morrione Andrea
Published: October 2003

Grb10 is a member of a superfamily of adapter proteins that includes Grb10, 7, 14, and a protein of Caenorhabditis elegans called Mig10. Grb10 proteins are binding partners for several trans‐membrane tyrosine‐kinase receptors, including the insulin‐like growth factor receptor (IGF‐IR) and the insulin receptor (IR). Many recent reports have suggested a very important role of Grb10 in regulating IGF‐IR signaling. In this review, we will focus on the role of Grb10 in IGF‐I‐induced mitogenesis and we will discuss the recent findings that show the involvement of Grb10 in the regulation of ligand‐induced ubiquitination, internalization, and stability of the IGF‐IR. J. Cell. Physiol. 197: 307–311, 2003© 2003 Wiley‐Liss, Inc.
How to overcome (and exploit) tumor hypoxia for targeted gene therapy
Authors: Greco Olga , Marples Brian , Joiner Michael C. , Scott Simon D.
Published: October 2003

Tumor hypoxia has long been recognized as a critical issue in oncology. Resistance of hypoxic areas has been shown to affect treatment outcome after radiation, chemotherapy, and surgery in a number of tumor sites. Two main strategies to overcome tumor hypoxia are to increase the delivery of oxygen (or oxygen‐mimetic drugs), and exploiting this unique environmental condition of solid tumors for targeted therapy. The first strategy includes hyperbaric oxygen breathing, the administration of carbogen and nicotinamide, and the delivery of chemical radiosensitizers. In contrast, bioreductive drugs and hypoxia‐targeted suicide gene therapy aim at activating cytotoxic agents at the tumor site, while sparing normal tissue from damage. The cellular machinery responds to hypoxia by activating the expression of genes involved in angiogenesis, anaerobic metabolism, vascular permeability, and inflammation. In most cases, transcription is initiated by the binding of the transcription factor hypoxia‐inducible factor (HIF) to hypoxia responsive elements (HREs). Hypoxia‐targeting for gene therapy has been achieved by utilizing promoters containing HREs, to induce selective and efficient transgene activation at the tumor site. Hypoxia‐targeted delivery and prodrug activation may add additional levels of selectivity to the treatment. In this article, the latest developments of cancer gene therapy of the hypoxic environment are discussed, with particular attention to combined protocols with ionizing radiation. Ultimately, it is proposed that by adopting specific transgene activation and molecular amplification systems, resistant hypoxic tumor tissues may be effectively targeted with gene therapy.
J. Cell. Physiol. 197: 312–325, 2003© 2003 Wiley‐Liss, Inc.
Transforming growth factor‐β induces expression of vascular endothelial growth factor in human retinal pigment epithelial cells: Involvement of mitogen‐activated protein kinases
Authors: Nagineni Chandrasekharam N. , Samuel William , Nagineni Sahrudaya , Pardhasaradhi Komanduri , Wiggert Barbara , Detrick Barbara , Hooks John J.
Published: October 2003

Vascular endothelial growth factor (VEGF) is a major agent in choroidal and retinal neovascularization, events associated with age‐related macular degeneration (AMD) and diabetic retinopathy. Retinal pigment epithelium (RPE), strategically located between retina and choroid, plays a critical role in retinal disorders. We have examined the effects of various growth factors on the expression and secretion of VEGF by human retinal pigment epithelial cell cultures (HRPE). RT‐PCR analyses revealed the presence of three isoforms of mRNA corresponding to VEGF 121, 165, and 189 that were up regulated by TGF‐β1. TGF‐β1, β2, and β3 were the potent inducers of VEGF secretion by HRPE cells whereas bFGF, PDGF, TGF‐α, and GM‐CSF had no effects. TGF‐β receptor type II antibody significantly reversed induction of VEGF secretion by TGF‐β. In contrast activin, inhibin and BMP, members of TGF‐β super family, had no effects on VEGF expression in HRPE. VEGF mRNA levels and protein secretion induced by TGF‐β were significantly inhibited by SB203580 and U0126, inhibitors of MAP kinases, but not by staurosporine and PDTC, protein kinase C and NF‐κB pathway inhibitors, respectively. TGF‐β also induced VEGF expression by fibroblasts derived from human choroid of eye. TGF‐β induction of VEGF secretion by RPE and choroid cells may play a significant role in choroidal neovascularization (CNV) in AMD. Since the secretion of VEGF by HRPE is regulated by MAP kinase pathways, MAP kinase inhibitors may have potential use as therapeutic agents for CNV in AMD. Published 2003 Wiley‐Liss, Inc. J. Cell. Physiol. 197: 453–462, 2003© 2003 Wiley‐Liss, Inc.
Defective P2Y purinergic receptor function: A possible novel mechanism for impaired glucose transport
Authors: Solini Anna , Chiozzi Paola , Morelli Anna , Passaro Angela , Fellin Renato , Virgilio Francesco Di
Published: October 2003

Extracellular ATP is an ubiquitous mediator that regulates several cellular functions via specific P2 plasma membrane receptors (P2Rs), for which a role in modulating intracellular glucose metabolism has been recently suggested. We have investigated glucose uptake in response to P2Rs stimulation in fibroblasts from type 2 diabetic (T2D) patients and control subjects. P2Rs expression was evaluated by RT‐PCR; intracellular calcium release by fluorometry; glucose transporter (GLUT1) translocation by immunoblotting and chemiluminescence; glucose uptake was measured with 2‐deoxy‐D‐[1‐3H]glucose (2‐DOG) and ATP by luminometry. Cells from T2D patients, in contrast to those from healthy controls, showed no increase in glucose uptake after ATP stimulation; extracellular ATP caused, however, a similar GLUT1 recruitment to the plasma membrane in both groups. P2Rs expression did not differ between fibroblasts from diabetic and healthy subjects, but while plasma membrane depolarization, a P2X‐mediated response was similar in both groups, no evident intracellular calcium increase was detectable in the cells from the former group. The calcium response in fibroblasts from diabetics was restored by co‐incubation with apyrase or hexokinase, suggesting that P2YRs in those cells were normally expressed but chronically desensitised. In support to this finding, fibroblasts from T2D subjects secreted a two‐fold larger amount of ATP compared to controls. Pre‐treatment with apyrase or hexokinase also restored ATP stimulated glucose uptake in fibroblasts from diabetic subjects. These results suggest that extracellular ATP plays a role in the modulation of glucose transport via GLUT1, and that the P2Y‐dependent GLUT1 activation is deficient in fibroblasts from T2D individuals. Our observations may point to additional therapeutic targets for improving glucose utilization in diabetes. J. Cell. Physiol. 197: 435–444, 2003© 2003 Wiley‐Liss, Inc.
Stable overexpression of specific segments of the P2P‐R protein in human MCF‐7 cells promotes camptothecin‐induced apoptosis
Authors: Gao S. , Scott R.E.
Published: October 2003

The stable overexpression of near full‐length P2P‐R protein in human Saos 2 cells restricts cell cycle progression by inducing mitotic arrest at prometaphase and mitotic apoptosis (Gao and Scott, 2002, J Cell Physiol 193: 199–207). Those effects of P2P‐R were observed in Saos‐2 cells that lack p53 and employ a caspase‐3‐dependent apoptotic signaling pathway. The current studies were performed to evaluate if overexpression of specific segments of the P2P‐R protein promote apoptosis in human MCF‐7 cells that contain p53 and employ a different apoptotic signaling pathway. Since segments of P2P‐R were found not to induce apoptosis independently, the ability of three different P2P‐R segments to promote camptothecin‐induced apoptosis was evaluated following their stable transfection and expression in MCF‐7 cells. Relative to full‐length P2P‐R (1–1560 aa), the three P2P‐R segments used in these studies included: P2P‐R‐2 (761–1560 aa), P2P‐R‐3 (1156–1560 aa), and P2P‐R‐4 (1314–1560 aa). The results document that overexpression of P2P‐R‐2 and P2P‐R‐3 promotes camptothecin‐induced apoptosis by three to fivefold when assayed by flow cytometric analysis of apoptotic sub 2n cell populations or by TUNEL assays. In contrast, P2P‐R‐4 had no effect on apoptosis. These results suggest that the ability of P2P‐R to promote camptothecin‐induced apoptosis in MCF‐7 cells involves a specific region (1156–1314 aa) that exists within P2P‐R. The data presented also show that the p53 binding domain of P2P‐R overlaps with the apoptosis‐associated region and previous studies documented that this region of P2P‐R also binds single‐strand nucleotides (Witte and Scott, 1997, Proc Natl Acad Sci USA 94: 1212–1217). Therefore, P2P‐R‐promoted apoptosis induced by camptothecin may be influenced by such interactions. J. Cell. Physiol. 197: 445–452, 2003© 2003 Wiley‐Liss, Inc.
A rapid method for assessment of plant residue quality
Authors: Praveen‐Kumar  , Tarafdar Jagadish C. , Panwar Jitendra , Kathju Shyam
Published: October 2003

A simple, reproducible and new method (modified dehydrogenase activity measurement after 72 h; DHA 72) was developed to assess plant residue quality for decomposition. The method resulted in similar assessments of residue quality than measurements of the C:N ratio, lignin:N ratio, and lignin and polyphenol concentration (PRQI). Among 25 plant residues tested, there was a large variation of DHA 72 as found in other well‐established methods. Based on cluster analysis, plant residues were grouped in four different classes; highly decomposable, moderately decomposable, slowly decomposable, and least decomposable. It is concluded that DHA 72 can very well be used to screen plant residues for residue quality judgment. The proposed method is very simple and easy to handle.
Uptake of residual phosphate and freshly applied diammonium phosphate byLolium perenneandTrifolium repens
Authors: Gallet Anne , Flisch René , Ryser Jean‐Pierre , Nösberger Joseph , Frossard Emmanuel , Sinaj Sokrat
Published: October 2003

Residual fertilizer phosphorus (residual P) may significantly contribute to crop P nutrition. To test this hypothesis, a pot experiment was conducted with ryegrass(Lolium perenne)and clover(Trifolium repens)grown separately on three different soils which either had not received P fertilizer for at least nine years (0F) or had received P fertilizer equivalent to crop P off‐take (F). Soils in the pot experiment were given either none (0F, F) or a single rate of 15 mg P (kg soil)–1as diammonium phosphate (0F+DAP, F+DAP). In the treatments0F+DAPandF+DAPDAP had been labeled with33PO4while in the treatments0FandFthe pool of available soil P had been labeled with carrier‐free33PO4. This allowed estimating the quantities of P in plant dry matter that derived from native soil P, residual fertilizer P or fresh fertilizer P. Fourteen to 62 % of the P in the above ground biomass of white clover or perennial ryegrass were derived from residual P whereas 7 to 28 % were derived from freshly applied DAP. The proportion of P derived from residual P was correlated to the total amount of P fertilizer added to the soils, while the proportion of P derived from DAP was correlated to the concentration of P in the soil solution of the0FandFsoils.
Effect of phosphate fertilization on crop yield and soil phosphorus status
Authors: Gallet Anne , Flisch René , Ryser Jean‐Pierre , Frossard Emmanuel , Sinaj Sokrat
Published: October 2003

To evaluate the effect of three phosphorus (P) fertilization regimes (no P, P input equivalent to P off‐take by crops, P input higher than P off‐take) on crop yield, P uptake, and soil P availability, seven field experiments (six in crop rotations, one under permanent grassland) were conducted in Switzerland during nine years (six trials) or 27 years (one trial). Soil total P (Pt), inorganic P (Pi), organic P (Po), and the amount of isotopically exchangeable soil P were measured in the 0–20 cm and 30–50 cm layers of the arable soils and in the 0–10 cm layer of the permanent grassland soil. Omitting P fertilization resulted in significant yield decreases only in one field crop trial as the amount of P isotopically exchangeable within one minute (E1min) reached values lower than 5 mg P (kg soil)–1. In the absence of P fertilization Pi decreased on average from 470 to 410 mg P (kg soil)–1 in the upper horizon of 6 sites while Po decreased only at two sites (from 510 to 466 mg P (kg soil)–1 on average). In all the treatments of the trials started in 1989 the E1min values of the upper horizon decreased on average from 15.6 to 7.4 mg P (kg soil)–1 between 1989 and 1998. These decreases were also observed when P inputs were higher than crops needs, showing that in these soils the highest P inputs were not sufficient to maintain the high initial available P levels. Finally for the six arable trials the values of the isotopic exchange kinetics parameters (R/r1, n, CP) and P exchangeable within 1 minute (E1min) at the end of the experiment could be estimated from the values measured at the beginning of trial and the cumulated P balance.
Effects of consecutive applications of gypsum in equal, increasing, and decreasing quantities on soil hydraulic conductivity of a saline‐sodic soil
Authors: Sahin Ustun , Oztas Taskin , Anapali Omer
Published: October 2003

The objective of this study was to determine the effects of consecutive application of gypsum dissolved in leaching water on hydraulic conductivity of a saline‐sodic soil. Drainage type plastic columns with a 10 cm diameter were used in this laboratory experiment. Soil depth within columns was 30 cm with an average bulk density of 1.38 g cm–3. Leaching water was applied in six equal portions. Total gypsum was applied at 1, 3, and 5 portions after dissolving in leaching water. In dissolution, equal (1.273 + 1.273 + 1.273 Mg ha–1), increasing (0.637 + 1.273 + 1.910 Mg ha–1) and decreasing (1.910 + 1.273 + 0.637 Mg ha–1) quantities of gypsum were used. Results were compared with the control treatment, in which total amount of gypsum were mixed with surface layer of soil column before leaching. Hydraulic conductivity of soil increased in all treatments. The maximum hydraulic conductivity value was obtained at consecutive application of gypsum at decreasing quantities.
Chemical changes in the rhizosphere of metal hyperaccumulator and excluder Thlaspi species
Authors: Puschenreiter Markus , Wieczorek Simone , Horak Othmar , Wenzel Walter W.
Published: October 2003

Rhizosphere processes involved in hyperaccumulation and exclusion of metals are still largely unknown. Therefore, we conducted a rhizobag experiment on contaminated and non‐contaminated soils to investigate the chemical changes in the rhizosphere of the hyperaccumulators Thlaspi goesingense and T. caerulescens, and the metal‐excluder T. arvense. Root growth was restricted to the rhizobags separated by a nylon membrane (7 μm \x 25 μm mesh size) from surrounding bulk soil. Depletion of labile Zn in rhizosphere could not explain the amount of metals accumulated in T. caerulescens, whereas the difference in EDTA‐extractable Zn even exceeded total plant uptake. Substantially increased DOC in T. arvense rhizosphere indicates alleviation of phytotoxicity by formation of metal‐organic complexes. Hyperaccumulation and depletion of labile Zn in the rhizosphere was observed for T. goesingense grown on contaminated soil. On non‐contaminated soil, Zn was accumulated but labile Zn in rhizosphere was not changed. Nickel present in background concentrations in both soils was accumulated by T. goesingense only when grown on non‐contaminated soil. In contrast, labile Ni in the rhizosphere was increased in both soils, suggesting a general tendency of Ni mobilization by T. goesingense.
Relationship between heme vinyl conformation and the protein matrix in peroxidases
Authors: Marzocchi Mario P. , Smulevich Giulietta
Published: October 2003

A direct relationship between the ν and Cb atoms of the vinyl groups and the surrounding atoms, the origin of the different vinyl orientations is ascribed to a variety of interactions, namely van der Waals contacts, weak π–π electron interactions and C—H···O hydrogen bonds. The vinyl group orientations appear to depend on the concerted orientations of the distal helix B and proximal helix F axes as controlled by the H‐bonds between the distal Arg, a heme propionyl group and a residue on the extended strand adjacent to proximal helix F. Finally, a possible mechanism explaining the alkaline configuration changes of cytochrome c peroxidase and the reorientation of a vinyl group upon fluoride complexation is given. Copyright © 2003 John Wiley & Sons, Ltd.
Applicability of laser‐induced Raman microscopy for in situ monitoring of imine formation in a glass microfluidic chip
Authors: Lee Moonkwon , Lee Jong‐Phil , Rhee Hakjune , Choo Jaebum , Gyu Chai Young , Kyu Lee Eun
Published: October 2003

Laser‐induced Raman microscopy has been used to illustrate its applicability for the in situ monitoring of imine formation reaction in a glass microfluidic chip. In order to monitor the diffusion process in a micro channel, the Raman spectra were measured at various points along the channel with a constant flow rate of 2.7 µl min−1. Time‐dependent Raman spectra were also measured without flow in order to monitor the variation of Raman peaks to a complete conversion. The disappearance of the CO stretching peak at 1700 cm−1 of the reactant, benzaldehyde, and the appearance of the Raman peak for the product, an imine, at 1628 cm−1 were successfully monitored. In addition, the intensity increases of three phenyl stretching modes in the 1550–1630 cm−1 region were also observed. The increase in Raman intensity for this vibrational mode is caused by an effective π‐electron conjugation between two phenyl rings through the —CN—bridging group of the product. Laser‐induced Raman microscopy enables us to monitor in situ product formation and to obtain detailed structural information in a glass microfluidic chip. Copyright © 2003 John Wiley & Sons, Ltd.
Raman spectroscopic study of spodumene (LiAlSi2O6) through the pressure‐induced phase change from C2/c to P21/c
Authors: Pommier C. J. S. , Denton M. B. , Downs R. T.
Published: October 2003

High‐pressure Raman spectroscopy was used to follow the effects of a phase transition on the Raman spectrum of a natural specimen of the pyroxene spodumene, from its low‐pressure (C2/c) to its high‐pressure (P21/c) phases. The transition occurred at 3.2 GPa and was accompanied by an increase from 15 to 23 observed peaks, owing to a decrease in symmetry. Comparisons were made with other pyroxenes with the same space groups. The change in Raman shift with pressure of all peaks observed is reported. An additional change in the spectrum is observed between 7.7 and 8.9 GPa, possibly due to the formation of an additional bond between Li and O3 or some other transition that retained the mineral's P21/c space group. Splitting of the peak appearing at ∼700 cm−1, used to characterize the P21/c phase in other studies, was not observed. Copyright © 2003 John Wiley & Sons, Ltd.
Low‐temperature Raman spectra of Sr0.66Ba0.34Nb2O6 single‐crystal fibers
Authors: Faria J. L. B. , Freire P. T. C. , Ayala A. P. , Melo F. E. A. , Filho J. Mendes , Paschoal C. W. A. , Santos I. A. , Eiras J. A.
Published: October 2003

A possible structural change in Sr0.66Ba0.34Nb2O6 single‐crystal fibers when the temperature decreases from 295 to 10 K was investigated by dielectric constant measurements and Raman spectroscopy. An anomaly observed in the dielectric constant and the loss factor is associated with the variation in the intensity and wavenumber of certain Raman modes. We observe that the relative intensity of low wavenumber modes has a singular behavior for the y(xz)ȳ scattering geometry. A high‐wavenumber band disappears when the temperature is lowered to 10 K for the y(xz)ȳ geometry and shifts to higher wavenumber for the y(zz)ȳ geometry. These observations can be interpreted as evidence of a structural phase transition undergone by Sr0.66Ba0.34Nb2O6 single‐crystal fibers at temperatures below 100 K. Copyright © 2003 John Wiley & Sons, Ltd.