bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Fourier-Domain Analysis. Part II: Determination of Boundary Conditions
Authors: Monfre Stephen L. , Brown Steven D.
Published: September 2005

A new approach for determining the boundary conditions of a Fourier-domain data set prior to performing quantitative multicomponent analysis has been developed. Processing boundary conditions were determined by calculating the condition number of the calibration matrix which contains the models used to describe the chemical system being studied. Once the boundary conditions for the Fourier-domain data set were determined, the Kalman filter was used to estimate the concentration of individual components in a multicomponent sample. Synthetic data were first analyzed to determine both the feasibility of the data-analysis method and the effect that background variations would have on the concentration estimates. Raw interferograms of multicomponent samples, collected with the use of Fourier transform infrared (FT-IR) spectroscopy, were also analyzed. Validation samples were analyzed to verify the chosen boundary conditions.
In situ Monitoring of Emulsion Polymerization using Fiber-Optic Raman Spectroscopy
Authors: Wang Chao , Vickers Thomas J. , Schlenoff Joseph B. , Mann Charles K.
Published: September 2005

The feasibility of a direct quantitative analysis of styrene by Raman spectroscopy during an emulsion polymerization is examined. A dispersive spectrometer fitted with an intensified diode array detector is used with excitation from the 514.5-nm line of an Ar-ion laser. The limits of detection are 0.26 weight percent styrene in the reaction mixture. Raman measurements are compared with those obtained by UV absorption measurements on extracted samples and found to give essentially the same results.
Evaluation and Analysis of Attenuated Total Reflectance FT-IR Spectra Using Kramers-Kronig Transforms
Authors: Huang J. B. , Urban M. W.
Published: September 2005

Two commonly used correction algorithms that were originally developed by Bertie and Dignam and their co-workers for quantitative analysis of ATR spectra are examined. It is shown that the Dignam theory is more suitable for strong ATR bands, whereas the Bertie algorithm is more applicable for weak bands. On the basis of analysis of possible deviation sources determined in the Bertie and Dignam theories, a new ATR algorithm is developed and analyzed. With this approach, the initial estimate of the absorption index spectrum is obtained by KK correlation of the intensity and the phase of the complex Fresnel reflection coefficient. An iterative process that minimizes the difference between the true and calculated reflectivity spectra while maintaining the KK relation between refractive and absorption indices is used in conjunction with the Maclaurin numerical KKT method. Such an approach appears to improve accuracies for both weak and strong ATR bands.
Surface Features of Conductors Eroded by Sputtering in a Magnetron Glow Discharge Plasma
Authors: Dehghan Khodayar , Shi Zhan , Woodrum Teresa Holbrook , Brewer Stephen , Sacks Richard
Published: September 2005

Surface characteristics of four different metals and alloys sputtered in Ar in a plasma generated by a previously described dc planar magnetron are examined. The study of Al alloy, Cu, brass, and Au samples indicates qualitatively that erosion increases with decreasing support gas pressure, increasing discharge currents, and increasing atomic number of the sputtered elements. These observations are supported by quantitative studies of mass loss rates as functions of support gas pressure, discharge current, and sample atomic number. Microscopic examination reveals hillocks formed on sputtered surfaces. With increased mass loss, hillocks tend to overlap. No correlation between inclusions and hillock locations is observed. Silver samples, though relatively (99.9%) pure, behave anomalously, acquiring a Cu coating at low discharge support gas pressures.
Role of Discharge Parameters and Limiting Orifice Diameter in Radio-Frequency Glow Discharge-Atomic Absorption Spectrophotometry (rf-GD-AAS)
Authors: Parker Mark , Marcus R. Kenneth
Published: September 2005

Studies are performed to evaluate the roles of discharge power and pressure as well as limiting orifice diameter on the production of free, gas-phase atoms with a radio-frequency glow discharge-atomic absorption spectrophotometry (rf-GD-AAS) atomizer. Results indicate that nominal pressures of ∼4 Torr Ar are optimal for conductive samples, whereas a pressure of ∼1 Torr is desired for nonconductive sample types. As might be expected, absorbance signals increase with increases in discharge power to a level of ∼30 W, though trade-offs between ablation rates and source stability exist at higher levels. Completely opposite to the bulk atomization characteristics, large limiting orifice diameters yield higher absorbances. Plasma stabilization times are seen to be on the order of 20 s after initiation of the plasma for conductive and nonconductive sample types. Despite limitations imposed by the current optical instrumentation, it is believed that rf powering in GD-AAS is a viable alternative to conventional dc-powered sources, with the advantage of direct analysis of nonconductive sample types.
Effect of Stereoregularity on TOF-SIMS Spectra of Polymers
Authors: Zimmerman Paul A. , Hercules David M.
Published: September 2005

This study shows the utility of time-of-flight secondary ion mass spectrometry (TOF-SIMS) for the analysis of stereoregular polymers. It is possible to obtain distinctive spectra for polymers of different stereoregularity. The high mass region of the spectrum from 600 to 3000 Da is related to differences in polymer stereoregularity. Differences occur in the relative intensities and/or locations of clusters for polymers of different stereoregularities. Polymers studied include poly(methyl methacrylate), polypropylene, and polypropylene oxide. The extent of stereoregularity influences the degree of difference observed in the TOF-SIMS spectra.
Indium Antimonide (InSb) Focal Plane Array (FPA) Detection for Near-Infrared Imaging Microscopy
Authors: Treado Patrick J. , Levin Ira W. , Lewis E. Neil
Published: September 2005

Near-infrared spectroscopy is a sensitive, noninvasive method for chemical analyses, and its integration with imaging technologies represents a potent tool for the study of a wide range of materials. In this communication the use of an indium antimonide (InSb) multichannel imaging detector for near-infrared absorption spectroscopic microscopy is described. In particular, a 128 × 128 pixel InSb staring array camera has been combined with a refractive optical microscope and an acousto-optic tunable filter (AOTF) to display chemically discriminative, spatially resolved, vibrational spectroscopic images of biological and polymeric systems. AOTFs are computer-controlled bandpass filters that provide high speed, random wavelength access, wide spectral coverage, and high spectral resolution. Although AOTFs inherently have a wide range of spectroscopic applications, we apply this technology to NIR absorption microscopy between 1 and 2.5 μm. The spectral interval is well matched to the optical characteristics of both the NIR refractive microscope and the AOTF, thereby providing near-diffraction-limited performance with a practical spatial resolution of 1 to 2 μm. Design principles of this novel instrumentation and representative applications of the technique are presented for various model systems.
Monitoring the Heterogeneously Catalyzed Conversion of Quadricyclane to Norbornadiene by Raman Spectroscopy
Authors: Ford Joseph F. , Mann Charles K. , Vickers Thomas J.
Published: September 2005

The utility of fiber-optic Raman spectroscopy for monitoring a heterogeneous catalysis reaction has been examined. The conversion of quadricyclane to norbornadiene in the presence of CuSO4 in chloroform has been followed by an automated procedure. Concentrations of both species have been measured at 5-min intervals over a period of several hours with the use of a solvent line as an internal standard. The nondestructive procedure is shown to be easily implemented. Limits of detection are about 0.003 M.
Reliability and Validity of a Swedish Language Version of the Resilience Scale
Authors: Nygren Björn , Randström Kerstin Björkman , Lejonklou Anna K. , Lundman Beril
Published: September 2005

The purpose of this study was to test the reliability and validity of the Swedish language version of the Resilience Scale (RS). Participants were 142 adults between 19–85 years of age. Internal consistency reliability, stability over time, and construct validity were evaluated using Cronbach’s alpha, principal components analysis with varimax rotation and correlations with scores on the Sense of Coherence Scale (SOC) and the Rosenberg Self-Esteem Scale (RSE). The mean score on the RS was 142 (SD= 15). The possible scores on the RS range from 25 to 175, and scores higher than 146 are considered high. The test-retest correlation was .78. Correlations with the SOC and the RSE were .41 (p< 0.01) and .37 (p< 0.01), respectively. Personal Assurance and Acceptance of Self and Life emerged as components from the principal components analysis. These findings provide evidence for the reliability and validity of the Swedish language version of the RS.
Psychometric Testing and Refinement of the Support Needs Inventory for Parents of Asthmatic Children
Authors: Toye Christine , Kristjanson Linda J. , Coleman Mardhie E. , Maltby Hendrika , Jackson Glenda
Published: September 2005

This study refined the Support Needs Inventory for Parents of Asthmatic Children (SNIPAC) (Coleman, Maltby, Kristjanson, & Robinson, 2001) to produce a more parsimonious tool to assess the importance and meet the support needs of parents of children with asthma. The original tool was completed by 145 parents of 199 children with asthma, and 74 of these also provided test-retest responses. Internal consistency reliability, construct validity, and stability over time were assessed and refinements were made. Internal consistency reliability of the revised 20-item tool ranged from .77 to .95 for the three subscales of the Parent’s Priority Scale (PPS), and .92 for the full PPS. Cronbach’s alphas ranged from .74 to .90 for the three subscales of the Parent’s Fulfillment Scale (PFS) and was .91 for the full scale. Factor analysis results of the PPS were compatible with the tool’s conceptual framework. The revised 20-item tool demonstrated adequate psychometric properties in most areas. This tool may be used for research or clinical screening without imposing undue burden on parents. Further work is required to establish the tool’s stability over time.
Women Who Use Violence in Intimate Relationships: The Role of Anger, Victimization, and Symptoms of Posttraumatic Stress and Depression
Authors: Swan Suzanne C. , Gambone Laura J. , Fields Alice M. , Sullivan Tami P. , Snow David L.
Published: September 2005

The present study examines the role of anger and victimization in women’s use of aggression in heterosexual intimate relationships. The sample was composed of 108 women, primarily African American, urban, and poor, who had used violence against a partner in the previous 6 months. Path modeling was used to examine the interrelationships among anger, women’s aggressive behavior, victimization, childhood abuse experiences, and symptoms of posttraumatic stress and depression. Results revealed that almost all of the women experienced violence from their partners. Greater frequency of victimization from partners and experiences of childhood abuse increased the likelihood that women would use aggression against their partners. Victimization from partners and childhood abuse also increased the likelihood that women would experience symptoms of posttraumatic stress and depression. Women with more symptoms of posttraumatic stress were also more likely to express anger outwardly towards others. Expressing anger outwardly toward others, in turn, predicted an increased likelihood of using aggression against partners.
A Qualitative Investigation of Johnson’s Typology
Authors: Rosen Karen H. , Stith Edd Sandra M. , Few April L. , Daly Kathryn L. , Tritt Dari R.
Published: September 2005

The couple typology described by Johnson and Ferraro (2000) provided the framework for this analysis of narrative accounts of couples in violent heterosexual relationships. Participants were 15 bidirectionally violent couples who were interviewed separately for about 1 hour each. Modified analytic induction guided the analyses. We categorized the violence in the relationships of these 15 couples in the following ways: 11 were categorized as “common couple” violence; two as “violent resistance”; one as “mutual violent control”; and one couple was categorized as what we named “pseudo-intimate terrorism.” We present rich descriptions of each category and motivations for and impacts of aggressive behavior as well as our rationale for classifying couples the way we did. Implications for intervention and future research are discussed.
Physical and Mental Health Outcomes of Women in Nonviolent, Unilaterally Violent, and Mutually Violent Relationships
Authors: Temple Jeff R. , Weston Rebecca , Marshall Linda L.
Published: September 2005

Despite equivocal findings on whether men or women are more violent, the negative impact of violence is greatest for women. To determine how gender asymmetry in perpetration affects women’s health status, we conducted a study in two phases with 835 African American, Euro-American, and Mexican American low-income women in Project HOW: Health Outcomes of Women. In Phase 1, we used severity and frequency of women’s and male partners’ violence to create six groups: nonviolent (NV), uni-directional male (UM) perpetrator, uni-directional female (UF) perpetrator and, when both partners were violent, symmetrical (SYM), male primary perpetrator (MPP), and female primary perpetrator (FPP). The MPP group sustained the most threats, violence, sexual aggression, and psychological abuse. They also reported the most fear. Injury was highest in the MPP and FPP groups. In Phase 2, we examined group differences in women’s health status over time for 535 participants, who completed five annual interviews. Surprisingly, women’s health in the MPP and FPP violence groups was similar and generally worse than if violence was uni-directional.
A Tale of Two Students: Building a Culture of Engagement in the Community College
Authors: McClenney Kay M. , Grtene Thomas
Published: September 2005

Enrolling in a community college may be as intimidating for those students who eventually succeed as it is for those who don't. Why, then, do some persevere while others leave before they meet their goals? Institutional practice can tip the balance.
A Learning Place: Ten Years in the Life of a New Kind of Campus Center
Authors: Misencik Karen E. , O'connor John S. , Young James
Published: September 2005

When George Mason University's Johnson Center opened a decade ago, it was on the leading edge of architectural design and innovative thinking about spaces for learning. Over time, the building has retained many of its revolutionary aspects even as it has accepted encroachments of conventionality.
Learning as a Dissonant Act
Authors: Kutnowski Martin
Published: September 2005

And teaching as the patience to watch
The New and the Rare: Luxury and Convenience in Japanese Depa‐chika
Authors: Takahashi Masaaki
Published: September 2005

In the face of economic adversity, the food sections of Japan's department stores have prospered, attracting large numbers of customers with their fresh produce, luxurious dishes and buzzing market‐like atmospheres. Masaaki Takahashi describes how these depa‐chika have not only met the demand for prepared foods among busy working people, but have also stimulated it. Selling the finest delicacies, they tempt their customers with rare items that are often bought for their novelty value alone.
Food for the City, Food in the City
Authors: Franck Karen A
Published: September 2005

KAREN A FRANCK notes that the luxury of eating and food shopping in slick new spaces often comes at the cost of losing more ethnically diverse small businesses. When we focus on this aspect of food and the city, though, we may lose sight of food in all its diversity ‐ as grown as well as consumed, as available or not available to those in poorer neighbourhoods. Viewing food as a system, even an urban system, brings many needs and opportunities to the fore.
Tasting the Periphery: Bangkok's Agri‐ and Aquacultural Fringe
Authors: McGrath Brian , Thaitakoo Danai
Published: September 2005

Brian McGrath and Danai Thaitakoo survey the ecosystem of Bangkok, ‘an amphibious city’ situated on a silted tidal delta. Influenced by Western planning ideas, the major roadways and infrastructure projects constructed since the Second World War remain out of kilter with local conditions. It is as if a consumer society, networked to global media and transport links, has been ‘superimposed on a wet rice‐cultivating landscape’.
The City as Dining Room: Big‐Sign Dining in Hong Kong
Authors: Cody Jeffrey W , Day Mary C
Published: September 2005

In Hong Kong, open‐air eateries that advertise their appetizing menus on big signs are the most common informal setting for consuming delicious food with friends and family. Jeffrey W Cody and Mary C Day seek out these ‘big‐sign’ eating places in the smallest alleyways as well as in the province's fresh‐food markets and, perhaps most surprisingly, in the midst of its postwar housing estates.
Designing the Gastronomic Quarter
Authors: Parham Susan
Published: September 2005

Throughout the world, urban gastronomic quarters, centred on fresh‐food markets, have been pulled back from the brink of extinction. Susan Parham explains how movements like Slow Food and Slow Cities in Italy, and the international demand for organic produce, have started to challenge the global food network of production and consumption. The growing revitalisation of urban quarters around produce markets not only serves customers seeking fresh produce, food products and lively cafés and restaurants, but also offers valuable lessons in urban design.
Walters and Cohen
Authors: Melvin Jeremy
Published: September 2005

Jeremy Melvin examines the work of a London‐based, South‐African‐born partnership, whose first commission was for an art gallery in Durban. He discovers how Cindy Walters and Michál Cohen are now able, in the UK, to put to good use the analytical skills wrought out of an atmosphere of political instability and uncertainty in their home country ‐ a background that has enabled them to work fruitfully with the British policy‐making establishment of government and the old‐school establishment at Bedales.
Jackson‐Triggs Niagara Estate Winery
Authors: Stanwick Sean
Published: September 2005

Sean Stanwick looks at a contemporary winery designed by Kuwabara Payne McKenna Blumberg Architects (KPMB) in Ontario, Canada, for the same client as Frank Gehry's in Le Clos Jordanne.
Numerical simulation of behavior of gas bubbles using a 3‐D front‐tracking method
Authors: van Sint Annaland M. , Dijkhuizen W. , Deen N. G. , Kuipers J. A. M.
Published: September 2005

In this paper a three‐dimensional (3‐D) front‐tracking (FT) model is presented featuring a new method to evaluate the surface force model that circumvents the explicit computation of the interface curvature. This method is based on a direct calculation of the net tensile forces acting on a differential element of the interface. Our model can handle a large density and viscosity ratio and a large value of the surface tension coefficient characteristic for gas–liquid systems. First, the results of a number of test cases are presented to assess the correctness of the implementation of the interface advection and remeshing algorithms and the surface tension model. Subsequently, the computed terminal Reynolds numbers and shapes of isolated gas bubbles rising in quiescent liquids are compared with data taken from the bubble diagram of Grace. In addition drag coefficients for rising air bubbles in water were successfully computed, a system that has proven difficult to simulate by other methods, and showed good agreement with existing correlations. Finally, a number of sample calculations involving multiple bubbles are reported to demonstrate the capabilities of our three‐dimensional FT model. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Optic atrophy and sensorineural hearing loss in a family caused by an R445H OPA1 mutation
Authors: Li Chunmei , Kosmorsky Gregory , Zhang Kang , Katz Bradley J. , Ge Jian , Traboulsi Elias I.
Published: September 2005

Autosomal dominant optic atrophy (ADOA) is the most common form of inherited optic atrophy. Four genetic loci have been associated with ADOA: OPA1, OPA2, OPA3, and OPA4. Out of these four loci, only one gene has been identified, OPA1. We previously described a unique syndrome of optic atrophy, sensorineural hearing loss, ptosis, and ophthalmoplegia in two unrelated families associated with an R445H mutation in OPA1. The R445H mutation is the only OPA1 mutation that has been associated with this syndrome. In this manuscript, we clinically characterize an unrelated family with four members affected by optic atrophy and hearing loss without extraocular motility abnormalities or ptosis. This family also harbors the R445H mutation. These cases help illustrate the intra‐ and inter‐family variability in phenotype associated with this mutation. As we continue to learn more about OPA1 and the function of its protein product, we will begin to understand the pathophysiology of optic atrophy. This understanding will ultimately lead to novel treatments directed toward preventing the visual loss and disability associated with this inherited disease. © 2005 Wiley‐Liss, Inc.
Delineation of the clinical phenotype associated with OPHN1 mutations based on the clinical and neuropsychological evaluation of three families
Authors: Chabrol B. , Girard N. , N'Guyen K. , Gérard A. , Carlier M. , Villard L. , Philip Nicole
Published: September 2005

Recent reports have demonstrated that mutations in the OPHN1 gene were responsible for a syndromic rather than non‐specific mental retardation. Abnormalities of the posterior fossa with cerebellar hypoplasia have been demonstrated in all male patients reported to date. We report here a new family with X‐linked mental retardation due to mutation in OPHN1 and present unpublished data about two families previously reported, concerning the facial and psychological phenotype of affected males and carrier females. Our study confirms that cerebellar hypoplasia is a hallmark of this syndrome. In addition, affected males display facial similarities that can help the diagnosis. Most carrier females have mild mental retardation and subtle facial changes. © 2005 Wiley‐Liss, Inc.
Clinical and molecular studies on two further families with Simpson‐Golabi‐Behmel syndrome
Authors: Rodríguez‐Criado Germán , Magano Luis , Segovia Mabel , Gurrieri Fiorella , Neri Giovanni , González‐Meneses Antonio , Gómez de Terreros Ignacio , Valdéz Rita , Gracia Ricardo , Lapunzina Pablo
Published: September 2005

The Simpson‐Golabi‐Behmel syndrome (SGBS) (OMIM 312870) is an overgrowth/multiple congenital anomalies syndrome caused by a semi‐dominant X‐linked gene encoding glypican 3 (GPC3). It shows great clinical variability, ranging from mild forms in carrier females to lethal forms with failure to thrive in males. The most consistent findings in SGBS are pre‐ and postnatal macrosomia, characteristic facial anomalies and abnormalities affecting the internal organs, skeleton, and on some occasions, mental retardation of variable degree. SGBS is also associated with an increased risk of developing embryonal tumors, mostly Wilms and liver tumors. We describe two molecularly‐confirmed families with SGBS. All patients had typical manifestations of SGBS including some female relatives who had minor manifestations of the disorder. Some patients had novel findings such as a deep V‐shaped sella turcica and six lumbar vertebrae. Molecular studies in affected patients showed a deletion of exon 6 in family 1 and an intronic mutation in family 2. © 2005 Wiley‐Liss, Inc.
Chromosome 11‐q24 region in Tourette syndrome: Association and linkage disequilibrium study in the French Canadian population
Authors: Díaz‐Anzaldúa Adriana , Rivière Jean‐Baptiste , Dubé Marie‐Pierre , Joober Ridha , Saint‐Onge Judith , Dion Yves , Lespérance Paul , Richer Francois , Chouinard Sylvain , Rouleau Guy Armand ,   The Montreal Tourette Syndrome Study Group
Published: September 2005

Previous studies have found association and linkage between Tourette syndrome (TS) and markers at the 11q24 region, mainly with markers D11S1377 and D11S933. In order to determine if these positive findings could be replicated in our sample, we undertook a family‐based association study in 199 French Canadian TS nuclear families. We genotyped 572 individuals from 174 complete and 25 incomplete TS trios. TDT analysis failed to detect an association between TS and six markers from 11q24. Furthermore, no haplotype combining alleles from D11S1377, D11S933, or any of the other four markers was associated with the disorder. Linkage disequilibrium analysis showed evidence of historical recombination between every contiguous pair of markers, indicating that these genetic variants are probably in equilibrium in the French Canadian population. Further analysis in additional families, with different methodologies (linkage and association) will be required in order to determine if the 11q24 region harbors a susceptibility locus for TS. If it does, this defect may not be frequent in the French Canadian population due to locus heterogeneity. © 2005 Wiley‐Liss, Inc.
New Approach to the ALD of Bismuth Silicates; Bi(CH2SiMe3)3 Acting as a Precursor for both Bismuth and Silicon
Authors: Harjuoja J. , Hatanpää T. , Vehkamäki M. , Väyrynen S. , Putkonen M. , Niinistö L. , Ritala M. , Leskelä M. , Rauhala E.
Published: September 2005

Bismuth silicate thin films were deposited using atomic layer deposition (ALD) with a novel precursor, Bi(CH2SiMe3)3, serving as both bismuth and silicon source. Precursor synthesis, analysis, and crystal structure are also reported. Bi(CH2SiMe3)3 forms hexagonal crystals with a = 10.7110(11) Å, b = 10.7110(11) Å, c = 10.2500(7) Å; space group P63. The deposition temperature of thin films was 200–450 °C, where a constant growth rate of 0.4 Å per cycle was obtained between 250 °C and 350 °C. Impurity levels of bismuth silicate films deposited at 250 °C were below 0.2 at.‐ % and 0.1 at.‐ % for carbon and hydrogen, respectively. The as‐deposited films were amorphous, and post‐synthetic annealing in an atmosphere of N2 or O2 at 400–1000 °C was applied.
Deposition of Palladium from a Cylcopentadienyl‐allyl‐palladium Precursor on Si‐Based Substrates with Various Pretreatments: The Role of Surface Si–OH and Si‐H Species Studied by X‐Ray Photoelectron Spectroscopy
Authors: Wu Q.‐H. , Gunia M. , Strunskus T. , Witte G. , Muhler M. , Wöll C.
Published: September 2005

The decomposition reactions of a metal‐organic precursor for the CVD of Pd, (Cp)Pd(allyl), on Si substrates with various terminated surfaces have been studied using X‐ray photoelectron spectroscopy (XPS). The XPS data show that mixed hydrogen/hydroxyl‐terminated Si surfaces exhibit the highest activity ascribed to acidic Si‐OH groups for precursor decomposition, followed by the as‐received Si surface. Clean, well‐defined SiO2 surfaces prepared in ultrahigh vacuum (UHV) exhibit the lowest activity for the Pd precursor decomposition, whereas the hydrogen‐terminated Si surface was rather active. Scanning electron microscopy (SEM) images show that Pd clusters were formed on the mixed hydrogen/hydroxyl‐terminated Si surface with a coverage of about 10 %. The average size of the Pd clusters is about 30 nm. Based on the XPS experimental data, a hydrogen‐assisted decomposition mechanism of the Pd precursor is proposed.
Continuous Synthesis of Y‐Junction Carbon Nanotubes by Catalytic CVD
Authors: Su L. F. , Wang J. N. , Yu F. , Sheng Z. M.
Published: September 2005

Cupric acetate dissolved in methanol was applied, for the first time, to the synthesizing of Y‐junction carbon nanotubes (CNTs). This was done by catalytic CVD of the methanol solution at 1000–1200 °C. Based on the bamboo structure, which was observed for the first time within Y‐junction CNTs, it is suggested that the growth of such CNTs may be a result of the fluctuation of external conditions causing a change in the growth direction of CNTs developed from completely melted Cu nanoparticles. Since the production process is continuous, the present technique can easily be scaled up for large‐scale production for a wide variety of applications.
Cationic Silver Coordination Compounds of Polydentate Ligands: Supramolecular Structures of [Ag(Pzbp2Py)2(OSO2CF3)] and [Ag2(Pzbp2Py)2(OSO2CF3)2] {Pzbp2Py = 2‐[3,5‐Bis(4‐butoxyphenyl)pyrazol‐1‐yl]pyridine}
Authors: Gallego M. Luz , Cano Mercedes , Campo José A. , Heras José V. , Pinilla Elena , Torres M. Rosario , Cornago Pilar , Claramunt Rosa M.
Published: September 2005

The new silver complexes [Ag(Pzbp2Py)2(OSO2CF3)], [Ag2(Pzbp2Py)2(OSO2CF3)2], [Ag(PzbpPy)2(OSO2CF3)], [Ag3(TPzbp2Tz)(OSO2CF3)3] and [Ag3(TPzbpTz)(OSO2CF3)3] (5–9) have been obtained by reaction of Ag(OSO2CF3) with the corresponding polydentate ligand 2‐[3,5‐bis(4‐butoxyphenyl)pyrazol‐1‐yl]pyridine (Pzbp2Py, 1), 2‐[3‐(4‐butoxyphenyl)pyrazol‐1‐yl]pyridine (PzbpPy, 2), 2,4,6‐tris[3,5‐bis(4‐butoxyphenyl)pyrazol‐1‐yl]‐1,3,5‐triazine (TPzbp2Tz, 3) and 2,4,6‐tris[3‐(4‐butoxyphenyl)pyrazol‐1‐yl]‐1,3,5‐triazine (TPzbpTz, 4), respectively. The coordination effects induced on the 1H, 13C and 15N NMR chemical shifts of the complexes in solution and in the solid state have been quantified, with the 15N NMR spectra being used as a tool to establish the coordination site. All complexes are consistent with an N,N′‐chelating coordination at each silver centre involving nitrogen atoms from pyrazole and pyridine groups for 5 and 7 or from pyrazole and triazine groups for 8 and 9. An additional Ag···OSO2CF3 interaction completes the environment around the silver atom, giving rise to a five‐coordination or a three‐coordination for complexes 5 and 7 and 8 and 9, respectively. The X‐ray structures of 5 and 6 confirm the presence of the N,N′‐chelating coordination of the Pzbp2Py ligands and the coordinative participation of the CF3SO3 counterion in the metal environment. The Ag···η2‐arene bonds between neighbouring units in 6 are responsible for the dimers containing four‐coordinate silver atoms. At a supramolecular level, Ag···O, C–H···O or C–H···F interactions generate a 2D network in both compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Metal Binding Within a Peptide‐Based Nucleobase Stack with Tuneable Double‐Strand Topology
Authors: Küsel Andrea , Zhang Jinhua , Alvariño Gil Miguel , Stückl A. Claudia , Meyer‐Klaucke Wolfram , Meyer Franc , Diederichsen Ulf
Published: September 2005

Peptide nucleic acid (PNA) oligomers with linear topology are synthesised with histidines at the central positions in order to provide metal‐ion coordination sites within the water shielded and non‐polar environment of a nucleobase stack that emerges upon duplex formation. Variation of the linker length used for attachment of the nucleobases to the regular peptide backbone allows for fine tuning of the distances and coordination environment at the metal binding site. The effect of zinc and copper incorporation into the modified alanyl‐PNA scaffolds on duplex stability was probed by temperature‐dependent UV spectroscopy, and additional insight was gained from EPR spectroscopy and EXAFS. Whenever four histidines (two per oligomer strand) are available, addition of Zn2+ significantly enhances double‐strand stability, thus supporting coordination of Zn2+ by the histidine‐N and incorporation of the metal ion within the base stack. In contrast to Zn2+, however, Cu2+ ions do not induce double‐strand formation of an alanyl/norvalyl‐PNA oligomer, as confirmed by EPR and EXAFS, which reveal a mixed {N2Ox} donor environment. While metal‐ion binding to histidine‐modified alanyl‐PNA oligomers (and homologues) is apparently feasible, a proper matching of the binding‐site geometry and the stereoelectronic requirements of the specific metal ion are essential in order to mediate double‐strand formation. This might offer new options for alternative pairing schemes in alanyl‐PNA chemistry in which metal coordination substitutes the common base‐pair H‐bonding pattern, and for metal‐dependent regulation of alanyl‐PNA duplex formation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Shape‐Induced Enhanced Luminescent Properties of Red Phosphors: Sr2MgSi2O7:Eu3+ Nanotubes
Authors: Wan Junxi , Wang Zhenghua , Chen Xiangying , Mu Li , Qian Yitai
Published: September 2005

Sr2MgSi2O7:Eu3+ nanotubes with red phosphor luminescent properties were successfully synthesized via a low‐temperature hydrothermal route in order to understand the underlying relationship between shape and luminescent properties. The one‐dimensional shape results in an obvious improvement of color purity. From emission spectra, the relative intensity of 5D0→7F2 to 5D0→7F1 transitions in tubular phosphors is higher than that of bulk material. The better color purity results from the more distorted lattices and relatively lower crystal symmetry around Eu3+ ions, which ascribes to the large surface area due to synthesize it in the form of nanotubes. Furthermore, the as‐synthesized tubular red phosphor has shorter fluorescent lifetime and blue‐shiftphenomenon in excitation spectra than that of the bulk counterpart. Based on these results, shape‐induced luminescent properties improvement is proposed as an efficient way to obtain red phosphors with high color purity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A New Model of Light‐Powered Chiral Molecular Motor with Higher Speed of Rotation, Part 1 – Synthesis and Absolute Stereostructure
Authors: Fujita Takuma , Kuwahara Shunsuke , Harada Nobuyuki
Published: September 2005

To develop a molecular motor with a higher speed of rotation, a new model light‐powered chiral molecular motor 2 of five‐membered ring type was designed, and the motor rotation isomers (–)‐2a and (–)‐2c were directly synthesized in enantiopure forms for the first time from the ketone (+)‐8. The precursor alcohols 9 and 10 were enantioresolved by the camphorsultam‐dichlorophthalic acid (CSDP acid; 3) method, and their absolute configurations were determined by X‐ray crystallographic analysis of the CSDP ester (–)‐11b and chemical correlations. The enantiopure ketone (S)‐(+)‐8 formed from (1S,2S)‐(+)‐9 or (1R,2S)‐(–)‐10 was subjected to the McMurry reaction with TiCl3/LiAlH4, yielding the motor rotation isomers [CD(–)257.8]‐(2S,2′S)‐(M,M)‐(E)‐(–)‐2a and [CD(–)270.0]‐(2S,2′S)‐(M,M)‐(Z)‐(–)‐2c. These studies enabled us unambiguously to determine the absolute stereostructure of the motor 2, which is of critical importance for control over the direction of motor rotation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A New Model of Light‐Powered Chiral Molecular Motor with Higher Speed of Rotation, Part 2 – Dynamics of Motor Rotation
Authors: Kuwahara Shunsuke , Fujita Takuma , Harada Nobuyuki
Published: September 2005

To clarify the mechanism and dynamics of the new model of light‐powered chiral molecular motor (2) of five‐membered ring type, the second motor rotation isomer, the unstable cis‐olefin 2b, was isolated and its stereostructure was determined. Similarly, the fourth motor rotation isomer, the unstable trans‐olefin 2d, was detected by 1H NMR at low temperature, and its stereostructure was also determined. With the aid of this knowledge of the stereostructures of the motor rotation isomers and their spectroscopic data, the dynamics of the motor rotation 2a → 2b → 2c → 2d → 2a were studied by 1H NMR and CD, revealing that the fourth rotation step 2d → 2a was much accelerated, as expected from the design of the new motor. Continuous rotation of this motor was achieved by repetition of the operations of photoirradiation and heating. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Physicochemical Characterization of meso‐Functionalized Corroles: Precursors of Organic–Inorganic Hybrid Materials
Authors: Barbe Jean‐Michel , Canard Gabriel , Brandès Stéphane , Guilard Roger
Published: September 2005

Cobalt(III) corroles exhibit an infinite selectivity for the coordination of carbon monoxide towards dioxygen and dinitrogen. This peculiar property thus allows their use as sensing devices for CO detection. Here are described the syntheses and physico‐chemical characterization of meso mono‐, bis‐ and tris(triethoxysilyl)‐functionalized corroles, precursors of organic–inorganic materials. The corrole ring formation was achieved in every case using the “2+1” method involving the reaction of two equivalents of an encumbered dipyrromethane with one equivalent of an aromatic aldehyde in the presence of a catalytic amount of trifluoroacetic acid. The functionalization of the corrole by triethoxysilyl chains was carried out by a condensation reaction of an isocyanate, bearing a triethoxysilyl termination, either on an amino or hydroxy group. Each final compound and intermediate were characterized by various physico‐chemical techniques such as 1H NMR, UV/Vis, MALDI/TOF or EI mass spectrometry and elemental analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A Convenient Method for the Generation of Allylic Dihaloboranes and Diallyl(chloro)borane and Their Application in the Allylboration of Alkenes and Acetylenes
Authors: Bubnov Yuri N. , Kuznetsov Nikolai Y. , Pastukhov Fedor V. , Kublitsky Vadim V.
Published: September 2005

A convenient approach to the highly reactive allylic dihaloboranes and diallyl(chloro)borane based on exchange reactions between BHal3 (Hal = Cl, Br) and allylic triorganoboranes (allyl, cinnamyl and 2‐methylenecyclobutane derivatives) has been developed. The compounds thus generated readily react with terminal alkenes and acetylenes to form the corresponding cis‐1,2‐allylboration products. These products were isolated by standard techniques and transformed into boronates (boron amides). Deboronation of these products led to 1,4‐pentadiene derivatives or unsaturated alcohols. 2‐Substituted 1,4‐pentadienyl(dichloro)boranes obtained from acetylenes underwent intramolecular chloroboration at a moderate temperature to form 5‐chloro‐2‐borinene derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Comparison of flame spread of textiles and burn injury prediction with a manikin
Authors: Rossi Rene M. , Bruggmann Georg , Stämpfli Rolf
Published: September 2005

The flame propagation rate of 94 different natural and synthetic fabrics and commercially available garments was assessed using the EN 1103 bench scale test apparatus. To further evaluate the potential burn hazard, the fabrics were then formed into upper garments, put on a full‐scale manikin equipped with 122 heat flux sensors and ignited with a small flame. By using a burn prediction model, the time to feel pain on the human skin as well as the time to suffer second degree burns could be calculated. The bench scale and full‐scale test data measurements show that the flame propagation rate is inversely proportional to the fabric weight for cellulose materials. The fabrics with the highest flame propagation rates were also the garments with the shortest times to pain and to second degree burns on the manikin. However, some blends of natural and synthetic fibres gave short pain and burn times on the manikin, even when the measured flame propagation rate using EN 1103 was low. Therefore, the flame propagation rate is a good means to predict the potential hazard of fabrics made of natural fibres; for synthetics and blends of natural and synthetic fibres, the heat transfer to the skin has to be considered as well. Copyright © 2005 John Wiley & Sons, Ltd.
Fire behaviour of polyester–clay nanocomposites
Authors: Gianelli Walter , Camino Giovanni , Tabuani Daniela , Bortolon Vittorio , Savadori Tonino , Monticelli Orietta
Published: September 2005

The aim of this study was on the one hand, to compare the fire behaviour of polyester/clay nanocomposites with that of the neat polymers added with the conventional flame retardant melamine isocyanurate (MIC) and on the other hand, to study the effect of the flame retardant added to the nanocomposites.

Polyester/clay nanocomposites were prepared by using polybutylene terephthalate (PBT) and a co‐polyester elastomer as polymeric matrices and a commercial organoclay as filler.

As verified by X‐ray diffractometry (XRD) and transmission electron microscopy (TEM) intercalated structures were obtained by mixing the molten polymer with the layered silicate in a corotating twin screw extruder.

The fire behaviour of these materials was investigated by means of an oxygen consumption calorimetry (Cone Calorimeter). Peak heat release rate of 3‐mm thick samples measured at 50 kW/m2 external heat flux was reduced by a factor of 2–3 by the addition of organically modified montmorillonite to the polymers. The further addition of MIC did not give a significant improvement in the behaviour of the materials. Copyright © 2005 John Wiley & Sons, Ltd.
Choroid plexus ependymal cells host neural progenitor cells in the rat
Authors: Itokazu Yutaka , Kitada Masaaki , Dezawa Mari , Mizoguchi Akira , Matsumoto Naoya , Shimizu Akira , Ide Chizuka
Published: September 2005

We previously demonstrated that choroid plexus epithelial (modified ependymal) cells (CPECs) differentiated into astrocytes after grafting into the spinal cord. In the present study, we examined whether CPECs from rats at postnatal 1 day (P1), 7 day (P7), and 8 weeks (P8W) can function as neural progenitor cells that give rise to neurons and glial cells. Cell spheres were produced in cultures of whole tissue of the choroid plexus from the fourth ventricle of rats at each postnatal period. β‐tubulin class III (Tuj‐1), glial fibrillary acid protein (GFAP)‐, and O4‐positive cells differentiated from cell spheres in the differentiation medium. We produced a monoclonal antibody 3E6 specifically labeling microvilli of CPECs. Using this monoclonal antibody, CPECs were isolated from the choroid plexus of P8W rats by cell sorter (FACS). Immunocytochemistry confirmed that there was no contamination from fibroblasts, endothelial cells, macrophages, or Schwann cells in the FACS‐isolated 3E6‐labeled cells. Cell spheres formed in the cultures of these 3E6‐labeled CPECs. After expansion, these cell spheres gave rise to Tuj‐1‐ (5%), GFAP‐ (45%), and O4‐positive cells (0.16%). The remaining cells (45%) were unlabeled neural or glial markers. Some CPECs of the P8W rat were immunohistochemically stained with lineage‐associated markers of Musashi‐1 and epidermal growth factor‐receptor (EGF‐R). In addition, infusion of EGF or fibroblast growth factor‐2 (FGF2) into the ventricle increased the number of bromodeoxyuridine (BrdU)‐positive cells among CPECs from 0.03% (untreated) to 1.14% (38‐fold, EGF) and 1.03% (35‐fold, FGF2), respectively. These findings indicate that neural progenitor cells exist among CPECs in the rat. © 2005 Wiley‐Liss, Inc.
Cortical progenitor cells in the developing human telencephalon
Authors: Howard Brian , Chen Yanhui , Zecevic Nada
Published: September 2005

Radial glial (RG) cells have been demonstrated to be a major neural progenitor cell type, but in the human fetal brain, neither their molecular nor their spatiotemporal characteristics are well known. We used glial and neuronal‐specific antibodies to determine the antigen characteristics and distribution of RG cells and other neuronal progenitors in the human brain during the first half of intrauterine development. Proliferating RG (4A4+) cells in the ventricular zone (VZ) showed clear caudorostral and ventrodorsal gradients, spreading from the spinal cord to the ventral rhombencephalon, at embryonic stages (4.5–5.5 gestational weeks [gw]). However, in the same embryo, other dividing cells expressed the neuronal marker SMI‐31 and were present throughout the entire CNS, including the rostral prosencephalon. At the beginning of cortical neurogenesis (6 gw), proliferating VZ cells labeled either with neuronal markers (SMI‐31, MAP2, β‐III‐tubulin), double‐labeled 4A4+/SMI‐31+ cells, or cells not labeled with these antibodies, were in close proximity to each other. At midgestation (17–24 gw), RG divisions were less frequent, but were spread throughout the entire cerebral cortex, including the subventricular and intermediate zones and the subpial granular layer. Several subtypes of RG were co‐labeled with vimentin and other glial markers (BLBP, GFAP, or GLAST) and quantified in vitro. In conclusion, the diversity of cortical progenitors in the human brain may, in part, explain the unique complexity of the human cerebral cortex. © 2005 Wiley‐Liss, Inc.
Calcium‐activated chloride channels in müller cells acutely isolated from tiger salamander retina
Authors: Welch Nicole C. , Lalonde Melanie R. , Barnes Steven , Kelly Melanie E.M.
Published: September 2005

Ca2+‐activated chloride channels were identified with whole‐cell patch‐clamp recording techniques in salamander retinal Müller cells. Cl(Ca) channels were activated by membrane depolarizations that elicited Ca2+ influx or the application of the Ca2+ ionophore, ionomycin. The Ca channel blocker, Cd2+, abolished the Cl(Ca) channel tail currents. Increasing the duration of the depolarizing pulse resulted in enhancement of the Cl(Ca) channel tail current. Repetitive depolarizations with rapid pulses to +20 mV produced a buildup of ICl(Ca), which reversed at 0 mV in symmetrical [Cl−] and at −40 mV when intracellular [Cl−] was reduced to 10% of the external concentration. ICl(Ca) was blocked by the Cl channel blocker niflumic acid, while niflumic acid had no effect on voltage‐gated Ca channels. These results offer the first demonstration of Cl(Ca) channels in a nonastrocytic glial cell and expand our understanding of the functional capacities of retinal glial cells. © 2005 Wiley‐Liss, Inc.
What is the function of hippocampal theta rhythm?—Linking behavioral data to phasic properties of field potential and unit recording data
Authors: Hasselmo Michael E.
Published: September 2005

The extensive physiological data on hippocampal theta rhythm provide an opportunity to evaluate hypotheses about the role of theta rhythm for hippocampal network function. Computational models based on these hypotheses help to link behavioral data with physiological measurements of different variables during theta rhythm. This paper reviews work on network models in which theta rhythm contributes to the following functions: (1) separating the dynamics of encoding and retrieval, (2) enhancing the context‐dependent retrieval of sequences, (3) buffering of novel information in entorhinal cortex (EC) for episodic encoding, and (4) timing interactions between prefrontal cortex and hippocampus for memory‐guided action selection. Modeling shows how these functional mechanisms are related to physiological data from the hippocampal formation, including (1) the phase relationships of synaptic currents during theta rhythm measured by current source density analysis of electroencephalographic data from region CA1 and dentate gyrus, (2) the timing of action potentials, including the theta phase precession of single place cells during running on a linear track, the context‐dependent changes in theta phase precession across trials on each day, and the context‐dependent firing properties of hippocampal neurons in spatial alternation (e.g., “splitter cells”), (3) the cholinergic regulation of sustained activity in entorhinal cortical neurons, and (4) the phasic timing of prefrontal cortical neurons relative to hippocampal theta rhythm. © 2005 Wiley‐Liss, Inc.
Erratum to: Factorizations and characterizations of induced‐hereditary and compositive properties
Authors: Farrugia Alastair , Mihók Peter , Richter R. Bruce , Semanišin Gabriel
Published: September 2005

The original article to which this Erratum refers was published in Journal of Graph Theory 49:11–27.

No Abstract.