bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive output, maternal age, and survivorship in captive common marmoset females (Callithrix jacchus)
Authors: Smucny Darlene A. , Abbott David H. , Mansfield Keith G. , Schultz‐Darken Nancy J. , Yamamoto M. Emilia , Alencar Anuska Irene , Tardif Suzette D.
Published: September 2004

Common marmosets (Callithrix jacchus) demonstrate significant variation in reproductive output on both a yearly and lifetime basis in comparison to other anthropoid primates. We explore the factors that may be most important in determining reproductive variation in captive common marmosets. Studies have found that maternal age, maternal condition, and dam survivorship are related to reproductive output; however, these reports are not in agreement and are far from conclusive. With the use of a large, multicolony, demographic database pooling data across five marmoset colonies, we examined litter information for 1,649 litters, and reproductive summaries for 400 dams to assess 1) how reproductive output variation (total production, total weaned production) is determined by litter size, interbirth interval (IBI), age at first birth, and dam survival age; 2) the relationship between maternal age and reproductive output variables; and 3) relationship between the reproductive output variables and survival. We used stepwise regression procedures to describe the amount of variation in lifetime reproductive output among dams, and found that mean litter size accounted for 18% of the variance in total production, survival age accounted for 10.6%, age at first birth accounted for 8.8%, and mean IBI accounted for 5%. For total (nonzero) weaned production, survival age accounted for 7.6% of variance, age at first birth accounted for 7.2%, mean IBI accounted for 2%, and mean litter size accounted for 1.6%. We identified significant effects (P<0.05) of maternal age on litter size and IBI length, but no effect of dam age on weaned litter size. Cox proportional hazards regression analyses revealed significant effects (P<0.01) of number of litters, age at first birth, and site on dam survivorship. Dams that produced more litters showed higher survivorship. Age at first birth showed a positive relationship with dam survivorship, i.e., dams that delayed first reproduction had higher survival. Our findings about reproductive variation in marmosets may have practical applications for the management of marmoset breeding colonies. Am. J. Primatol. 64:107–121, 2004 © 2004 Wiley‐Liss, Inc.
Investigation of shear effects on styrene free radical polymerization using a narrow channel reactor
Authors: Leveson P. , Dunk W. A. E. , Jachuck R. J.
Published: September 2004

Spinning disc reactor technology has been demonstrated to achieve significant enhancements in the rates of free radical polymerization. It is believed that these enhancements are related to the centrifugal and shear conditions that exist on the disk and it is the objective of this study to elucidate the role of shear in thin films in a plug flow regime. Polymerizing systems have been subjected to shear fields in the range of 0.4 to 2,173 s−1 and comparisons between conversion profiles and polymer product properties have been made. It has been found that shear fields have little or no effect on these systems while the reaction is in the kinetically controlled regime and it is concluded that the observed rate enhancements of free radical polymerization on a spinning disk are not largely attributable to the high rates of shear experienced by the thin film as it traverses the disk. Our studies therefore continue to assess the role of flow divergence and centrifugal extension in the kinetics of polymerization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94:1365–1369, 2004
Characterization of the formation and degradation of a polyacrylamide microgel
Authors: Chen Fangeng , Wang Hongjuan , Zhu Chuanfeng , Ren Lingling , Li Jing
Published: September 2004

The morphology of polyacrylamide microgel in gelation and degelation procedures is characterized by atomic force microscopy. The polymer concentration, the cross‐linker concentration, and the type of cross‐linker have significant influence on the microstructure of polyacrylamide. The changes in aggregation status result in changes in the rheological properties of the polymer solution and microgel. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94:1375–1380, 2004
New polymer syntheses XXVIII. Synthesis and thermal behavior of new organometallic polyketones and copolyketones based on diferrocenylidenecyclohexanone
Authors: Aly Kamal I.
Published: September 2004

A new interesting category of organometallic polyketones and copolyketones were synthesized via the Friedel–Crafts reaction through the polymerization of 2,6‐[bis (2‐ferrocenyl)methylene] cyclohexanone (II) with different diacid chlorides. The model compound was synthesized by reacting the monomer (II) with benzoyl chloride and characterized by 1H‐NMR, IR, and elemental analyses. The polyketones and copolyketones were insoluble in most organic solvents but easily soluble in protic solvents. The thermal properties of these polyketones and copolyketones were evaluated and correlated to their structural units by thermogravimetric analysis and DSC measurements, and they had inherent viscosity of 0.29–0.52 dI g−1. Moreover, the electrical conductivity of one of the polyketones, as a selected example, namely poly [carbonyl‐terephthaloyloxy‐ (2‐oxo‐1,3‐cyclohexanediylidene)methylidyne‐ferrocenyl], Va, and copolyketone, VI, was investigated above the temperature range (300–500 K) and it followed an Arrhenius equation with activation energy 2.09 eV. The morphological properties of selected example of polyketones were determined by scanning electron microscopy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1440–1448, 2004
Synthesis and characterization of poly(glycidyl methacrylate)/Na‐montmorillonite nanocomposites
Authors: Çelik Meltem , Önal Müşerref
Published: September 2004

Poly(glycidyl methacrylate)/Na–montmorillonite nanocomposites were synthesized by free‐radical polymerization of glycidyl methacrylate containing dispersed montmorillonite. By changing the concentration of glycidyl methacrylate several polymer–clay nanocomposites were prepared and the resulting nanocomposites were characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The results indicated that the properties of the composite were significantly improved. The thermogravimetric analysis results revealed that the degradation temperatures of nanocomposites were higher than that of pure polymer and the thermal degradation rates decreased. Examination of these materials by scanning electron microscopy showed that the clay layers are dispersed homogenously in the polymer matrix and the formation of intercalation nanostructure. Furthermore, adsorptive, moisture regain, and water uptake properties of nanocomposites were also investigated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1532–1538, 2004
Methods to determine solubility parameters of polymers at high temperature using inverse gas chromatography
Authors: Huang Jan‐Chan
Published: September 2004

Experimental values of Flory–Huggins parameters, χ, between polymers and probes, are frequently used to determine the solubility parameters of the polymers by the method of DiPaola–Baranyi and Guillet. The solubility parameters of probes were usually estimated by using heat of vaporization. When χ is measured at a temperature near the critical temperature of the probes and used to determine the solubility parameter of polymers, the departure of enthalpy of the probe vapor from the ideal gas state should be considered. This study discussed the method to make the correction and its effect on the determination solubility parameter of polymers. Without correction in the vapor phase enthalpy, the solubility parameters of the probes and polymer tend to be underestimated and the error increases when the critical temperature is approaching. Analytical expressions for the effect of correction on the solubility parameter of probes and parameters of polymers were derived. By use of probes with a range of solubility parameters on both sides of the solubility parameter of polymers, the correlation between parameters of polymers was shown to be reduced. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1547–1555, 2004
U1 RNA induces innate immunity signaling
Authors: Hoffman Robert W. , Gazitt Tal , Foecking Mark F. , Ortmann Robert A. , Misfeldt Michael , Jorgenson Rebecca , Young Steven L. , Greidinger Eric L.
Published: September 2004

Objective

The U1–70‐kd RNP is a prominent target of autoimmunity in connective tissue diseases. In this study, we explored whether its endogenous ligand, U1 RNA, mediates a proimmune signal and may be immunogenic.

Methods

We assayed the proliferation of control and MyD88‐knockout splenocytes in response to in vitro–synthesized U1 RNA, and measured interleukin‐6 (IL‐6) and IL‐8 secretion induced by U1 RNA in a human cell line competent for signaling through Toll‐like receptor 3 (TLR‐3) and TLR‐5.

Results

Treatment with U1 RNA or with poly(I‐C), a known agonist of TLR‐3, induced approximately twice as much control splenocyte proliferation as did treatment with RNase‐digested U1 RNA. Proliferation in response to either poly(I‐C) or U1 RNA by MyD88‐knockout splenocytes was similarly attenuated. Similar to poly(I‐C), U1 RNA induced significant secretion of both IL‐6 and IL‐8 from a TLR‐3–expressing human cell line; in contrast, the TLR‐5 agonist flagellin induced predominantly IL‐8 secretion. Pretreatment of U1 RNA with RNase abolished IL‐6 and IL‐8 secretion.

Conclusion

U1 RNA is capable of inducing manifestations consistent with TLR‐3 activation. The ability of U1 RNA (which has a substantial double‐stranded secondary structure) to activate TLR‐3 may contribute to the immunogenicity of the U1–70‐kd autoantigen. Stimulation of innate immunity by native RNA molecules with a double‐stranded secondary structure may help explain the high prevalence of autoimmunity to RNA binding proteins.
Up‐regulation of microsomal prostaglandin E synthase 1 in osteoarthritic human cartilage: Critical roles of the ERK‐1/2 and p38 signaling pathways
Authors: Masuko‐Hongo Kayo , Berenbaum Francis , Humbert Lydie , Salvat Colette , Goldring Mary B. , Thirion Sylvie
Published: September 2004

Objective

Microsomal prostaglandin E synthase 1 (mPGES‐1) is the final enzyme of the cascade that produces prostaglandin E2 (PGE2), a key actor in arthritis. To study mPGES‐1 synthesis in human cartilage and its regulation by interleukin‐1β (IL‐1β), we used human cartilage and an immortalized human chondrocyte cell line. Furthermore, we investigated the signaling pathways involved in mPGES‐1 expression.

Methods

We used real‐time quantitative reverse transcription–polymerase chain reaction, Northern blotting, and Western blotting to measure mPGES‐1 messenger RNA (mRNA) and protein expression in human chondrocytes. PGE2 production was measured by enzyme‐linked immunosorbent assay.

Results

Cartilage specimens from osteoarthritis (OA) patients contained far greater amounts of mPGES‐1 and cyclooxygenase 2 (COX‐2) mRNA than did normal cartilage. Incubation with IL‐1β markedly increased mPGES‐1 mRNA and protein in a dose‐dependent and time‐dependent manner, in parallel with an increase in PGE2 levels. Both PD98059, an ERK pathway inhibitor, and SB203580, a p38α/β MAPK inhibitor, abolished the increases in mPGES‐1 mRNA and protein in response to IL‐1β. The specific p38α MAPK inhibitor SC906 suppressed IL‐1β–induced COX‐2 expression but not IL‐1β–induced mPGES‐1 expression, suggesting preferential involvement of p38β MAPK in IL‐1β–induced mPGES‐1 expression.

Conclusion

This study is the first to show that mPGES‐1 is stimulated in human chondrocytes by the proinflammatory cytokine IL‐1β via activation of both ERK‐1/2 and p38 MAPK in an isoform‐specific manner. We postulate that mPGES‐1 may be a novel target for OA therapy.
Deletion of the gene encoding CD59a in mice increases disease severity in a murine model of rheumatoid arthritis
Authors: Williams A. S. , Mizuno M. , Richards P. J. , Holt D. S. , Morgan B. P.
Published: September 2004

Objective

To investigate the roles of CD59a in the protection of joint tissue in the context of murine antigen‐induced arthritis (AIA).

Methods

AIA was triggered in CD59a‐deficient (CD59a−/−) mice and in CD59a‐sufficient (CD59a+/+) controls; the course and severity of disease were compared between groups. The effects on arthritis of restoring CD59 to the joint in CD59a−/− mice by use of a membrane‐targeted recombinant CD59 were also explored.

Results

Disease, as assessed clinically by measurement of joint swelling on day 1 (P < 0.0001), day 2 (P < 0.01), and day 7 (P < 0.02) and histologically from indicators of joint damage on day 21 (P < 0.02), was significantly enhanced in CD59a−/− mice compared with CD59a+/+ wild‐type controls. Membrane attack complex (MAC) deposition in the arthritic joints of CD59a−/− mice was also increased compared with that in the joints of CD59a+/+ controls. Restitution of CD59 activity in joints of CD59a−/− mice was attempted with soluble recombinant rat CD59 (sCD59) or with a novel membrane‐targeted rat CD59 derivative (sCD59‐APT542). Strong immunohistochemical staining of the synovial membrane and subsynovial tissue was apparent in sCD59‐APT542–injected joints, but not in joints injected with untargeted sCD59. Intraarticular administration of sCD59‐APT542 markedly ameliorated disease severity in CD59a−/− mice, knee swelling was significantly reduced over the time course of the disease, and joint damage, assessed histologically, was significantly milder on day 21 (P < 0.05).

Conclusion

These data firmly implicate the MAC of complement as a major effector of joint damage in the murine AIA model of rheumatoid arthritis (RA), and they provide a rationale for the inhibition of MAC assembly as a therapeutic strategy for RA.
Efficacy of modified recombinant type II collagen in modulating autoimmune arthritis
Authors: Myers L. K. , Tang B. , Brand D. D. , Rosloniec E. F. , Stuart J. M. , Kang A. H.
Published: September 2004

Objective

Previous studies have shown that an analog peptide of the immunodominant T cell determinant of type II collagen (CII), i.e., CII256–276(N263, D266), was able to suppress the immune response to CII and the development of arthritis in DR1‐transgenic mice. The present study tested the hypothesis that introduction of the same amino acid substitutions into full‐length CII might improve the efficacy of the mutant collagen in achieving suppression of autoimmune arthritis.

Methods

Using recombinant technology, full‐length CII was modified, while the native conformation was retained. Two point mutations were introduced within the immunodominant T cell determinant to convert the F263 to N and E266 to D, using a baculovirus expression system that has previously been utilized in the production of recombinant CII (rCII).

Results

The mutant rCII(N263, D266) was capable of reducing the incidence and severity of arthritis as well as the antibody response to CII when administered to DR1‐transgenic mice that display susceptibility to collagen‐induced arthritis. More importantly, it was significantly more effective than the synthetic analog peptide, CII256–276(N263, D266). Its mechanism of suppression may be explained by the secretion of predominantly Th2 cytokines by the T cells immunized with rCII(N263, D266). Administration of rCII(N263, D266) was ineffective in suppressing arthritis in IL4−/− mice, suggesting that the profound suppressive effects of rCII(N263, D266) were mediated through the production of interleukin‐4.

Conclusion

These findings describe a promising specific immunotherapy for patients with DR1‐mediated autoimmunity to CII.
Historische Ziegeldeckenkonstruktionen
Authors: Voormann Friedmar
Published: September 2004

Bei Sanierungsvorhaben von Gebäuden, die etwa in dem Zeitabschnitt zwischen 1890 und 1930 erbaut wurden, stößt man häufig auf ebene massive Deckenkonstruktionen aus Ziegelhohlsteinen. Bei Spannweiten ab etwa 1,40 m findet man meistens zwischen den Ziegelsteinschichten Bewehrungen aus Flachstahl. Sowohl bei den unbewehrten als auch bei den bewehrten Ziegeldecken, den Stahlsteindecken stand den Bauschaffenden der damaligen Zeit eine große Vielzahl unterschiedlichster Konstruktionen zur Verfügung. Der folgende Beitrag gibt einen Einblick in die Entwicklungsgeschichte dieser äußerst effektiven Deckentragsysteme.
Neuartige vernagelte Lamellen‐Stützwand
Authors: Lohmiller Hermann
Published: September 2004

Aus der Reihe von verschiedenen bepflanzbaren, dauerhaften Sicherungen von Geländeeinschnitten wird eine neuartige Lamellen‐Stützwand beschrieben. Sie zeichnet sich dadurch aus, daß sie aus horizontalen, im Erdreich verankerten Stahlbetongurten besteht, in deren Schutz die endgültige Aushubsohle erreicht wird, und daran später von unten nach oben fortschreitend, befestigten Fertigteil‐Lamellen. Die Verankerungen bestehen vorzugsweise aus schlaffen Nägeln Es können aber auch Spannanker verwendet werden. Die Vorzüge dieser Bauweise werden hervorgehoben. Ein ausgeführtes Beispiel wird mit mehreren Fotos dargestellt und beschrieben. Anschließend wird auf die Besonderheiten eines vom Verfasser entwickelten Computer‐Programms hingewiesen, mit dem nicht nur die beschriebene Konstruktion, sondern auch alle anderen vernagelten Stützwände, insbesondere die mit Spritzbeton verkleideten, berechnet werden können. Dabei werden neue Wege beschritten, die zu schnelleren und genaueren Ergebnissen führen.
Vergabeentscheidung und Wirtschaftlichkeitsberechnung von PPP/PFI‐Projekten in der Bauwirtschaft
Authors: Blecken Udo , Meinen Heiko , Holthaus Ursula
Published: September 2004

Bei den PPP/PFI‐Projekten prüft die öffentliche Hand die Kosten des Eigenbaus der Verwaltung gegenüber den Leasingangeboten des privatwirtschaftlichen Betreibers. Die Kosten für die Risiken sind in den PPP‐Wirtschaftlichkeitsvergleich systematisch einzubinden. Für solch eine PSC‐Berechnung werden die Risiken anhand von zwei Handlungsvarianten mit der DCF‐Methode und dem VaR‐Ansatz berechnet und wirtschaftliche Konsequenzen der einzelnen PPP‐Parteien sowie die Renditeerwartung aufgezeigt.
Neural tube defects and associated anomalies in South Carolina
Authors: Stevenson Roger E. , Seaver Laurie H. , Collins Julianne S. , Dean Jane H.
Published: September 2004

BACKGROUND

Neural tube defects (NTDs) occur as isolated malformations and in the company of other birth defects. This study was conducted to determine the frequency of coexisting anomalies and the relationship between them.

METHODS

Since 1992, NTDs have been identified through prenatal and postnatal surveillance activities in South Carolina. The type of NTD and presence of associated anomalies were determined by prenatal ultrasound, postnatal and/or postmortem examination.

RESULTS

During the ten‐year period from 1992 to 2002, 564 NTDs were identified by the surveillance system. Seventeen percent of NTDs (98/564) had associated malformations. In approximately half (n = 51) of these cases, the NTDs and associated anomalies were components of a recognizable syndrome. In the remaining cases (n = 47), no syndrome was identified or suspected, but the associated anomalies were believed in most instances to be secondary to space limitation or neural crest abnormalities imposed by the NTD.

CONCLUSION

Seventeen percent of NTDs in South Carolina have associated malformations. In most cases, the associated anomalies are considered either components of a multiple malformation syndrome or secondary to the NTD. Birth Defects Research (Part A) 70554–558, 2004. © 2004 Wiley‐Liss, Inc.
Maternal age and non‐chromosomal birth defects, Atlanta—1968–2000: Teenager or thirty‐something, who is at risk?
Authors: Reefhuis Jennita , Honein Margaret A.
Published: September 2004

OBJECTIVE

This investigation explored the association between maternal age and non‐chromosomal birth defects to assess any increased risk associated with maternal age.

METHODS

Birth defect cases were ascertained by the Metropolitan Atlanta Congenital Defects Program (MACDP), denominator information was obtained using birth certificate data. Infants with any chromosomal diagnosis were excluded. Effect estimates were calculated using 5‐year maternal age categories with 25–29 years as the referent. Multiple logistic regression was used to adjust for maternal race, parity, infant sex, and birth year.

RESULTS

A total of 1,050,616 singleton infants, born after ≥20 weeks gestation in the five counties of metropolitan Atlanta from 1968 through 2000 who did not have a chromosomal abnormality and whose mother was 14 to 40 years old, were included in the analyses, 32,816 of them were identified with birth defects by the MACDP. Young maternal age (14–19 years) was associated with anencephaly (OR = 1.81, 95% CI = 1.30–2.52), hydrocephaly without neural tube defect (OR = 1.56, 95% CI = 1.23–1.96), all ear defects (OR = 1.28, 95% CI = 1.10–1.49), cleft lip (OR = 1.88, 95% CI = 1.30–2.73), female genital defects (OR = 1.57, 95% CI = 1.12–2.19), hydronephrosis (OR = 1.42, 95% CI = 1.11–1.82), polydactyly (OR = 1.29, 95% CI = 1.09–1.52), omphalocele (OR = 2.08, 95% CI = 1.39–3.12), and gastroschisis (OR = 7.18, 95% CI = 4.39–11.75). Advanced maternal age (35–40 years) was associated with all heart defects (OR = 1.12, 95% CI = 1.03–1.22), tricuspid atresia (OR = 1.24, 95% CI = 1.02–1.50), right outflow tract defects (OR = 1.28, 95% CI = 1.10–1.49), hypospadias 2nd degree or higher (OR = 1.85, 95% CI = 1.33–2.58), male genital defects excluding hypospadias (OR = 1.25, 95% CI = 1.08–1.45) and craniosynostosis (OR = 1.65, 95% CI = 1.18–2.30).

CONCLUSIONS

Young and advanced maternal ages are associated with different types of birth defects. Underlying causes for these associations are not clear. Birth Defects Research (Part A) 70:572–579, 2004. Published 2004 Wiley‐Liss, Inc.
Klebstoffe der Natur: Anwendung und Perspektiven für die Technik
Authors: Onusseit Hermann
Published: September 2004

Auf Grund der zum Teil einzigartigen Eigenschaften von altbewährten Rohstoffen aus der Natur, aber auch wegen der Möglichkeiten, natürliche Rohstoffe durch chemische Modifikation gezielt zu verändern, werden Naturstoffe in einer Vielzahl von Klebstoffen eingesetzt. Dass es sich bei den natürlichen Klebstoffen um nachwachsende Rohstoffe handelt, spielt bei einer ökologischen Betrachtung eine wichtige Rolle.
Erst seit einigen Jahren ist die Wissenschaft in der Lage, die Naturphänomene des Klebens so genau zu untersuchen, dass direkte Ableitungen und daraus resultierende technische Anwendungen möglich sind. Durch Modifikationen natürlicher Rohstoffe (beispielsweise gentechnisch veränderte Sorten) wird in Zukunft ein weiteres Einsatzspektrum dieser Stoffe als Klebstoffe möglich sein.
Die Gesellschaft für Technische Biologie und Bionik
Authors: Irsch Wilhelm
Published: September 2004

Um die Bionik in der Öffentlichkeit bekannt zu machen, gründeten Saarbrücker Biologen im Mai 1990 die “Gesellschaft für Technische Biologie und Bionik (GTBB)”. Einer der Initiatoren war Werner Nachtigall, inzwischen emeritierter Direktor des Zoologischen Instituts an der Saar‐Universität, der kurz zuvor auch einen entsprechenden Studienschwerpunkt “Technische Biologie und Bionik (TBB)” ins Leben gerufen hatte.
Ernst Mayr
Authors: Irsch Wilhelm
Published: September 2004

Ernst Mayr, einer der bedeutendsten Biologen des 20. Jahrhunderts, feierte in diesem Jahr seinen 100. Geburtstag. Der Inhaber von rund 20 Ehrendoktortiteln und Träger zahlreicher internationaler Auszeichnungen zählt zu den größten und einflussreichsten Naturforschern unserer Zeit.
Determination of abacavir in human plasma by high‐performance liquid chromatography with ultraviolet detection and the analytical error function
Authors: Ferrer Salut M. , Modamio Pilar , Lastra Cecilia F. , Mariño Eduardo L.
Published: September 2004

A rapid and simple high‐performance liquid chromatography method has been developed for the determination of the HIV‐1 reverse transcriptase inhibitor abacavir in human plasma. It included a single liquid–liquid extraction procedure with a mixture of ethyl acetate‐diethyl ether prior to reversed‐phase chromatography on a C18 column and C18 precolumn insert. Ultraviolet detection was set at 285 nm. The mobile phase consisted of water–acetonitrile (83:17, v/v) and the ﬂow rate was kept at 1 mL/min. The total run time for a single analysis was 10 min. The method has been validated over the range 50–2500 ng/mL. The assay was linear over the entire concentration range (r2 = 0.9993). Intra‐ and inter‐day precision and accuracy were less than 8.1 and −5.2%, respectively. The extraction recovery was greater than 94.3%. Abacavir was stable under the relevant storage conditions tested. After the validation, the analytical error function was established as standard deviation (SD; ng/mL) = −1.072 + 0.037C (C = theoretical concentration value). The method developed and its associated analytical error function will be suitable for pharmacokinetic studies and monitoring of HIV‐1 patients. Copyright © 2004 John Wiley & Sons, Ltd.
A comprehensive and concise assessment of suicide risk
Authors: Packman Wendy L. , Marlitt Rebecca E. , Bongar Bruce , O'Connor Pennuto Tracy
Published: September 2004

Because suicide is one of the few fatal consequences of psychiatric illness and is a source of extraordinary stress for loved ones and the clinician, accurate assessment of suicidal risk is an essential aspect of the mental health profession. Innumerable individual differences, along with the low base rate of suicide, make assessment a challenging task in clinical practice that is both delicate and time consuming. In this article, the authors recommend examining and incorporating each patient's personal characteristics, dispositional factors, situational factors, and current presentation of symptoms into a unique individual picture of suicidal risk. This portrait of potential for suicidal behavior can, in turn, be used to evaluate risk and design a course of action. This thorough yet concise approach will likely reduce omissions in assessment, and hopefully lead to fewer false negatives and fewer deaths of suicidal patients. Copyright © 2004 John Wiley & Sons, Ltd.
Re‐presentation and resistance in the context of school exclusion: reasons to be critical
Authors: Howarth Caroline
Published: September 2004

In this article an examination of how we, in the everyday, develop critical engagement with the shifting relations of power and oppression around us is presented. The article explores the role of representations in maintaining the racialized patterns of school exclusion in Britain. Social representations theory is used to investigate how racializing re‐presentations pervade and create institutionalized practices, how these re‐presentations invade young people's sense of self and ultimately how young people collaborate to resist and reject oppressive relations. The material presented here, from interviews with young people excluded from school, and parents, teachers and others involved in school exclusion, illustrates how young people problematize and critique racializing re‐presentations while participating in the conditions of oppression and resistance that pervade their experiences of school. The discussion is divided into three sections. The first examines the institutionalization of stigmatizing representations, visible in social practices. The second section looks at the role of re‐presentation in the social construction of ‘Black pupils’. The concluding section explores the possibilities of resistance and critical engagement in the everyday. As a whole this reveals how young people develop critical engagement with the re‐presentations that filter into and so constitute their realities. This enables an analysis of the role of resistance and contestation in social re‐presentation, highlights the importance of participation and community and so invites a critical version of social representations theory. Copyright © 2004 John Wiley & Sons, Ltd.
Conformation Analysis of Glu181 and Ser186 in the Metarhodopsin I State
Authors: Ishiguro Masaji
Published: September 2004

Photoactivation of rhodopsin yields a photointermediate, metarhodopsin I, during the formation of the fully activated photointermediate, metarhodopsin II. It is proposed that Glu181 and Ser186, in the second extracellular loop, play important roles in the stabilization of the protonated Schiff base of metarhodopsin I. Glu181 and Ser186 form a network of hydrogen bonds mediated by a water molecule in the dark‐state crystal structure of rhodopsin. On the other hand, the counter‐ion of the protonated Schiff base, Glu113, is not involved in the hydrogen‐bond network, as it is located further than hydrogen‐bond distance from Ser186. Herein, the conformations and proton arrangements of the protonated form of Glu181 and Ser186 in the hydrogen‐bond network have been investigated by molecular‐dynamics calculations of the rhodopsin crystal structure as well as in the structural model of metarhodopsin I. In the metarhodopsin I model, Ser186 mediated the hydrogen‐bond network between Glu113 and Glu181, changing the protein's conformation and creating a space by the outward motion of transmembrane segment 3, while the hydroxyl group of Glu181 was favored in the hydrogen‐bond network. The hydrogen bond between Glu113 and Ser186 is thought to reduce the basicity of the carboxylate of Glu113, maintaining the protonated state of the Schiff base in the metarhodopsin I state. In the Glu181Gln mutant, the hydroxyl group of Ser186 favored the water molecule as a proton donor in the metarhodopsin I state, since the carbonyl group of the Gln residue was favored in the hydrogen‐bond network. These results indicate that the Gln181 residue interferes with the hydrogen‐bond between Glu113 and Ser186 in the metarhodopsin I state, facilitating the neutralization of the protonated Schiff base.
Bubble Behavior of a Large‐Scale Bubble Column with Elevated Pressure
Authors: Jin H. , Yang S. , Zhang T. , Tong Z.
Published: September 2004

Gas holdups and the rising velocity of large and small bubbles are measured using the dynamic gas disengagement approach in a pressured bubble column of 0.3 m in diameter and 6.6 m in height. The effects of superficial gas velocity, liquid surface tension, liquid viscosity, and system pressure on the gas holdups and the rising velocity of small and large bubbles are investigated. The holdup of large bubbles and the rising velocity of small bubbles increase with increasing liquid viscosity and liquid surface tension. Meanwhile, the holdup of small bubbles and the rising velocity of a swarm of large bubbles decrease. Moreover, the holdup of large bubbles and the rising velocity of a swarm of small bubbles decrease with increasing system pressure. A correlation for the holdup of small bubbles is obtained from experimental data.
Complexing Mechanism of the Lanthanide Cations Eu3+, Gd3+, and Tb3+ with 1,4,7,10‐Tetrakis(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane (dota)—Characterization of Three Successive Complexing Phases: Study of the Thermodynamic and Structural Properties of the Complexes by Potentiometry, Luminescence Spectroscopy, and EXAFS
Authors: Moreau Juliette , Guillon Emmanuel , Pierrard Jean‐Claude , Rimbault Jean , Port Marc , Aplincourt Michel
Published: September 2004

Complexation of the lanthanides Eu3+, Gd3+, and Tb3+ with 1,4,7,10‐tetrakis(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane (dota) has been studied in solution by using potentiometry, luminescence spectrometry, and EXAFS. Three series of successive complexes were characterized by at least two of these methods: the immediate [LnHn(dota)](n−1)+** and intermediate [LnHn(dota)](n−1)+* complexes with 0≤n≤2, and the final [Ln(dota)]− complexes. The formation constants of the intermediate and final complexes were determined by using potentiometry. From the results, a complexation mechanism involving three steps has been proposed. In the [LnHn(dota)](n−1)+** complexes that are instantaneously formed, the lanthanide is bound to four oxygen atoms of the carboxylate groups and to five water molecules. These species evolve rapidly: the lanthanide moves into the macrocycle cavity, two new bonds are formed with two nitrogen atoms diametrically opposed in the tetraaza cycle and only three water molecules remain bound to the lanthanide in the [LnHn(dota)](n−1)+* (0≤n≤2) complexes, which appear after a two‐day wait. These compounds are stable for about four days. After 4–8 weeks, a concerted rearrangement occurs which leads to the formation of thermodynamically stable [Ln(dota)]− complexes in which the lanthanide is bound to four nitrogen atoms, four carboxylate oxygen atoms, and one water molecule.
Crystal and Molecular Structures and Experimentally Determined Charge Densities of Fluorinated Ethenes
Authors: Lentz Dieter , Bach Ansgar , Buschmann Jürgen , Luger Peter , Messerschmidt Marc
Published: September 2004

Crystals of various fluorinated ethenes were grown by in situ crystallization from their melts on a diffractometer, allowing the structures of tetrafluoroethene (C2F4), trifluoroethene (C2HF)3, 1,1‐difluoroethene (C2H2F2), (E)‐1,2‐difluoroethene (C2H2F2), and (Z)‐1,2‐difluoroethene (C2H2F2) to be determined by X‐ray crystallography. Unexpectedly, the CC bond lengths show only small variations arising from fluorine substitution. These findings are supported by ab initio calculations at a DFT level of theory and the results of topological analyses of the experimentally determined and theoretically calculated charge densities.
Towards Targeted MRI: New MRI Contrast Agents for Sialic Acid Detection
Authors: Frullano Luca , Rohovec Jan , Aime Silvio , Maschmeyer Thomas , Prata M. Isabel , de Lima J. J. Pedroso , Geraldes Carlos F. G. C. , Peters Joop A.
Published: September 2004

The detection of sialic acid in living systems is of importance for the diagnosis of several types of malignancy. We have designed and synthesized two new lanthanide ion ligands (L1 and L2) that are capable of molecular recognition of sialic acid residues. The basic structure of these ligands consists of a DTPA‐bisamide (DTPA, diethylenetriamine pentaacetic acid) whose amide moieties each bear both a boronic function for interaction with the diol groups in the side chain of sialic acid, and a functional group that is positively charged at physiologic pH values and is designed to interact with the carboxylate anion of sialic acid. The relaxometric properties of the Gd3+ complexes of these two ligands were evaluated. The relaxivity of the GdL1 complex has a significant second‐sphere contribution at pH values above the pKa of its phenylboronic acid moiety. The interaction of the Gd3+ complexes of L1 and L2 with each of several saccharides was investigated by means of a competitive fluorescent assay. The results show that both complexes recognize sialic acid with good selectivity in the presence of other sugars. The adduct formed by GdL2 with sialic acid has the higher conditional formation constant (50.43±4.61 M−1 at pH 7.4). The ability of such complexes to recognize sialic acid was confirmed by the results of a study on the interaction of corresponding radiolabeled complexes (153SmL1 and 153SmL2) with C6 glioma rat cells. 153SmL2 in particular is retained on the cell surface in significant amounts.
Compressed Octahedral Coordination in Chain Compounds Containing Divalent Copper: Structure and Magnetic Properties of CuFAsF6 and CsCuAlF6
Authors: Mazej Zoran , Arčon Iztok , Benkič Primož , Kodre Alojz , Tressaud Alain
Published: September 2004

Crystal structures and magnetic investigations of CuFAsF6 and CsCuAlF6 are reported. Together with KCuAlF6, these appear to be the only examples of Jahn–Teller pure CuII compounds containing only one type of ligand that exhibits a compressed octahedral coordination geometry. The Rietveld method has been used for refining the CsCuAlF6 structure based on neutron powder diffraction data at 4 K. The compound crystallizes in space group Pnma (no. 62) with a=7.055(1), b=7.112(1), c=10.153(1) Å and Z=4 at 4 K. The structure is built from infinite [CuF5]n3n− chains of [CuF6]4− octahedra running along the [1 0 0] direction and (AlF6)3− octahedra connected by corners in the trans position, thus giving rise to chains oriented along the [0 1 0] direction. Single crystals of CuFAsF6 were prepared under solvothermal conditions in AsF5 above its critical temperature. The structure was determined from single‐crystal data. CuFAsF6 crystallises in the orthorhombic space group Imma (No. 74) with a=10.732(5), b=6.941(3), c=6.814(3) Å and Z=4 at 200 K. The structure can also be described in terms of one‐dimensional infinite [CuF5]n3n− chains of tilted [CuF6]4− octahedra linked by trans‐vertices running along the b axis. The [CuF5]n3n− chains are connected through [AsF6]− units sharing joint vertices. The compressed octahedral coordination of CuII atoms in CuFAsF6 and CsCuAlF6 compounds at room temperature is confirmed by Cu K‐edge EXAFS (extended x‐ray absorption fine structure) analysis. For both compounds strong antiferromagnetic interactions within the [CuF5]n3n− chains were observed (θp=−290±10 K and θp=−390±10 K for CuFAsF6 and CsCuAlF6, respectively). The peculiar magnetic behaviour of chain compounds containing divalent copper at low temperature could be related to uncompensated magnetic moments in the one‐dimensional network.
The Reaction of [FeII(tpa)] with H2O2 in Acetonitrile and Acetone—Distinct Intermediates and Yet Similar Catalysis
Authors: Mairata i Payeras Antoni , Ho Raymond Y. N. , Fujita Megumi , Que, Lawrence
Published: September 2004

The reaction of [FeII(tpa)(OTf)2] (tpa=tris(2‐pyridylmethyl)amine) and its related 5‐Me3‐tpa complex with hydrogen peroxide affords spectroscopically distinct iron(III)–peroxo intermediates in CH3CN and acetone. The reaction in acetonitrile at −40 °C results in the formation of the previously reported FeIII–OOH intermediate, the end‐on hydroperoxo coordination mode of which is established in this paper by detailed resonance Raman isotope‐labeling experiments. On the other hand, the reaction in acetone below −40 °C leads to the observation of a different peroxo intermediate identified by resonance Raman spectroscopy to be an FeIII–OOC (CH3)2OH species; this represents the first example of an intermediate derived from the adduct of H2O2 and acetone. The peroxoacetone intermediate decays more rapidly than the corresponding FeIII–OOH species and converts to an FeIVO species by OO bond homolysis. This decay process is analogous to that observed for [FeIII(tpa)(OOtBu)]2+ and in fact exhibits a comparable enthalpy of activation of 54(3) kJ mol−1. Thus, with respect to their physical properties at low temperature, the peroxoacetone intermediate resembles [FeIII(tpa)(OOtBu)]2+ more than the corresponding FeIII–OOH species. At room temperature, however, the behavior of the Fe(tpa)/H2O2 combination in acetone in catalytic hydrocarbon oxidations differs significantly from that of the Fe(tpa)/tBuOOH combination and more closely matches that of the Fe(tpa)/H2O2 combination in CH3CN. Like the latter, the Fe(tpa)/H2O2 combination in acetone catalyzes the hydroxylation of cis‐1,2‐dimethylcyclohexane to its tertiary alcohol with high stereoselectivity and carries out the epoxidation and cis‐dihydroxylation of olefins. These results demonstrate the subtle complexity of the Fe(tpa)/H2O2 reaction surface.
Ortho‐Chalcogenostannates as Ligands: Syntheses, Crystal Structures, Electronic Properties, and Magnetism of Novel Compounds Containing Ternary Anionic Substructures [M4(μ4‐Se)(SnSe4)4]10− (M=Mn, Zn, Cd, Hg), ${{{\hfill 3\atop \hfill \infty }}}${[Hg4(μ4‐Se)(SnSe4)3]6−}, or ${{{\hfill 1\atop \hfill \infty }}}${[HgSnSe4]2−}
Authors: Brandmayer Michael K. , Clérac Rodolphe , Weigend Florian , Dehnen Stefanie
Published: September 2004

By reaction of K4[SnSe4]⋅1.5 MeOH with CdCl2 or Hg(OAc)2 in water/methanol it was possible to prepare single crystals of four novel compounds that contain ternary anionic coordination oligomers and polymers: [K10(H2O)16(MeOH)0.5][M4(μ4‐Se)(SnSe4)4] (4: M=Cd, 5: M=Hg), [K6(H2O)3][Hg4(μ4‐Se)(SnSe4)3]⋅MeOH (6), and K2[HgSnSe4] (7), which were structurally characterized by single‐crystal X‐ray diffraction. The optical absorption properties of the isostructural compounds 4 and 5, as well as those of the recently reported Zn (2) and Mn (3) analogues, were studied by UV‐visible spectroscopy. These investigations showed the quaternary phases to have relatively small optical gaps for their molecular size (2.2–2.6 eV), which are similar to the excitation energies that were observed for mesostructured solids of the respective combination of elements. According to DFT investigations on the ternary anions, an experimentally observed difference between the absorption behavior of the d10 compounds 2, 4, and 5 and the open‐shell d5 compound 3 is in line with different characters of the frontier orbitals in the two cases. Both the calculations and a magnetic measurement on 3 demonstrated antiferromagnetic coupling between the μ4‐Se‐bridged Mn centers.
A Simple, Efficient and Regioselective Oxychlorination of Aromatic Compounds Using Ammonium Chloride and Oxone®.
Authors: Narender N. , Mohan K. V. V. Krishna , Srinivasu P. , Kulkarni S. J. , Raghavan K. V.
Published: September 2004

For Abstract see ChemInform Abstract in Full Text.
Palladium(0)‐Catalyzed Direct Cross‐Coupling Reaction of Allyl Alcohols with Aryl‐ and Vinyl‐Boronic Acids.
Authors: Tsukamoto Hirokazu , Sato Masanori , Kondo Yoshinori
Published: September 2004

For Abstract see ChemInform Abstract in Full Text.
Polyoxo Anions: Synthesis and Structure
Authors: Pope M. T.
Published: September 2004

For Abstract see ChemInform Abstract in Full Text.
Genomic analysis of prostate carcinoma specimens obtained via ultrasound‐guided needle biopsy may be of use in preoperative decision‐making
Authors: Teixeira Manuel R. , Ribeiro Franclim R. , Eknæs Mette , Wæhre Håkon , Stenwig Anna E. , Giercksky Karl E. , Heim Sverre , Lothe Ragnhild A.
Published: September 2004

BACKGROUND

The widespread use of prostate‐specific antigen (PSA) testing to screen for prostate carcinoma has led to significant overdiagnosis, due to the frequent detection of indolent malignancies on PSA screening. The detection of abnormal PSA levels typically is followed by ultrasound‐guided needle biopsy. Therefore, in an effort to identify genetic markers that augment the information provided by standard histopathologic classification, the authors tested the feasibility of using these minute biopsy samples for genomic profiling via chromosome banding analysis and comparative genomic hybridization (CGH).

METHODS

Ultrasound‐guided needle biopsy specimens obtained preoperatively from 35 patients with prostate carcinoma were analyzed via chromosome banding analysis (after short‐term culturing) and CGH. The findings of these analyses then were analyzed for potential correlations with clinicopathologic parameters.

RESULTS

Chromosome banding analysis and CGH were possible in 34 and 33 of the 35 study specimens, respectively. Combined analysis revealed aberrations in 69% of all samples investigated. Copy number losses occurred most commonly at 8p (58% of all abnormal specimens), 16q (42%), and 13q (37%), whereas the only gains detected in more than 1 specimen were those that occurred at 8q (37%). Genomic imbalances and losses at 16q were significantly associated with more poorly differentiated subtypes of prostate carcinoma (P = 0.048 and P = 0.019, respectively), whereas gains at 8q and losses at 16q were significantly correlated with clinically advanced disease (P = 0.048 for the finding of a gain at 8q together with a loss at 16q; P = 0.01 for the finding of either aberration alone).

CONCLUSIONS

The authors conclude that genomic analysis of suspected prostate carcinoma specimens obtained via ultrasound‐guided needle biopsy is feasible. Thus, it may be possible to use genetic markers to obtain diagnostic and/or prognostic information that is useful in the making of preoperative decisions regarding prostate carcinoma management. Cancer 2004. © 2004 American Cancer Society.
Growth of bismuth tri‐iodide platelets by the physical vapor deposition method
Authors: Cuña A. , Noguera A. , Saucedo E. , Fornaro L.
Published: September 2004

The work reports the growth of single BI3 crystals with platelets habit. Platelets were grown by physical vapor deposition (PVD) in a high vacuum atmosphere and with argon, polymer or iodine as additives. Crystals grew in the zone of maximum temperature gradient, perpendicular to the ampoule wall. Crystals grown with argon as additive show a very shining surface, have hexagonal (0 0 l) faces, sizes up to 20 x 10 mm2 and thicknesses up to 100 μm. They were characterized by optical microscopy and scanning electron microscopy (SEM). Dendritic‐like structures were found to be their main surface defect. SEM indicates that they grow from the staking of hexagonal unities. Electrical properties of the crystals grown under different growth conditions were determined. Resistivities up to 2 x 1012 Ωcm (the best reported value for monocrystals of this material) were obtained. X‐ray response was measured by irradiation of the platelets with a 241Am source of 3.5 mR/h. A comparison of results according to the growth conditions was made. Properties of the crystals grown by this method are compared with the ones measured for others previously grown from the melt. Also, results for bismuth tri‐iodide platelets are compared with the ones obtained for mercuric and lead iodide platelets. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
How can SMEs effectively implement the CSR agenda? A UK case study perspective
Authors: Castka Pavel , Balzarova Michaela A. , Bamber Christopher J. , Sharp John M.
Published: September 2004

This paper focuses on implementation of the CSR agenda in small‐to‐medium enterprises (SMEs) and reports on research findings from an action research case study that has been conducted in a UK based SME. The case study research demonstrates how the CSR agenda has been implemented using ISO 9001:2000 as a platform and what benefits the case study organization has gained from this approach. These results are compared with a UK survey on feasibility of CSR for SMEs conducted by the UK's Department of Trade and Industry and parallels are drawn. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Neuromorphic architectures for nanoelectronic circuits
Authors: Türel Özgür , Lee Jung Hoon , Ma Xiaolong , Likharev Konstantin K.
Published: September 2004

This paper reviews recent important results in the development of neuromorphic network architectures (‘CrossNets’) for future hybrid semiconductor/nanodevice‐integrated circuits. In particular, we have shown that despite the hardware‐imposed limitations, a simple weight import procedure allows the CrossNets using simple two‐terminal nanodevices to perform functions (such as image recognition and pattern classification) that had been earlier demonstrated in neural networks with continuous, deterministic synaptic weights. Moreover, CrossNets can also be trained to work as classifiers by the faster error‐backpropagation method, despite the absence of a layered structure typical for the usual neural networks. Finally, one more method, ‘global reinforcement’, may be suitable for training CrossNets to perform not only the pattern classification, but also more intellectual tasks. A demonstration of such training would open a way towards artificial cerebral‐cortex‐scale networks capable of advanced information processing (and possibly self‐development) at a speed several orders of magnitude higher than that of their biological prototypes. Copyright © 2004 John Wiley & Sons, Ltd.