bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning acoustic microscopy investigation of melted collagen in thermoplastic leather
Authors: Wyler A. , Golan G.
Published: March 2008

A scanning acoustic microscope (SAM) has been used to investigate the structure of thermoplastic leather. This material is formed by pressing fibers of leather under high pressure and moderate temperature. The result is a matrix from transformed, melted fibers in which leftover fibers act as reinforcement. Unlike the scanning electron microscope (SEM), the SAM is able to distinguish between completely and incompletely transformed fibers and also to penetrate the material beneath the surface. The results show that the matrix is built as a domain structure. The advantages of the SAM over the SEM for organic materials are indicated.
Plastic deformation in impure nanocrystalline ceramics
Authors: Chaim Rachman
Published: March 2008

Plastic deformation behavior of impure nanocrystalline ceramics (NCC) was modeled using the percolative composite model in conjunction with models for plastic deformation by grain boundary sliding. The “glass transition temperature” concept was used to determine the threshold strain rate criterion below which the impure nanocrystalline ceramic would deform plastically. Threshold strain rate is stress independent. It increases with the temperature increase and with the grain size decrease. Using the dissolution-precipitation model, dependence of the strain rate on temperature, stress, and grain size in the nanometer regime for impure NCCs was calculated. As an example, the critical conditions for plasticity in impure yttria-tetragonal zirconia polycrystals (Y-TZP) were evaluated. At 600 °C, strain rates as high as 10−4 s−1 were expected in 10 nm impure Y-TZP. Comparison of the published data extrapolated into the nanometer range to the calculated threshold level showed that increase in the applied stress is associated with increase in the grain size and strain rate onsets for plastic deformation.
Microstructural studies by transmission electron microscopy of the formation of ultrathin PtSi layers with novel silicidation processes
Authors: Jin S. , Bender H. , Donaton R. A. , Maex K.
Published: March 2008

Ultrathin and uniform Pt-silicide layers are prepared by electron beam evaporation on a heated silicon substrate and by magnetron sputtering at room temperature followed by rapid thermal annealing (RTP) and selective etching, respectively. In the electron-beam deposited samples, continuous Pt-silicide layers of 6–8 nm thickness are formed after thermal annealing. The interfaces between the silicide layers and the silicon substrate are not atomically flat. In the case of the sputtered Pt, continuous PtSi layers down to 3 nm thick can be produced by using two-step (low-high temperature) and modified two-step (selective etch and high-temperature anneal) RTP silicidation processes. In one-step (high-temperature) processed samples, PtSi is the dominant phase; meanwhile, a small fraction of Pt12Si5 phase is inhomogeneously distributed in the case of thicker PtSi layers. In the two-step RTP processed samples, a Pt/Pt2Si/PtSi/Si layered structure is formed after the first RTP step. The first anneal step is found to be crucial for the roughness and epitaxy of the final PtSi layer. The best Schottky barrier heights are found to be 0.249 eV for the 3 nm PtSi/p-Si(100) Schottky diodes. The e-beam and the sputtered PtSi layers follow different epitaxial growth models.
Influence of compositional disorder on optical absorption processes in Cu6P(S1−xSex)5I crystals
Authors: Studenyak I. P. , Kranjčec M. , Kovacs Gy. Sh. , Desnica-Franković I. D. , Panko V. V. , Slivka V. Yu.
Published: March 2008

The fundamental absorption edge of Cu6P(S0.6Se0.4)5I and Cu6P(S0.4Se0.6)5I crystals was studied in the 77–320 K temperature range where no phase transitions were revealed by optical techniques. The temperature behavior of the exponential Urbach absorption edge in Cu6P(S0.6Se0.4)5I and Cu6P(S0.4Se0.6)5I crystals was analyzed. The effect of compositional disorder upon the Urbach edge parameters, parameters of exciton-phonon interaction, and lattice parameters in Cu6P(S1−xSex)5I, 0 ≤ x ≤ 1, crystals was studied. The effect of various types of disordering upon the optical absorption processes in Cu6P(S1−xSex)5I crystals is discussed.
Melt processing of Ba2CuO3: Textured precursor for the fabrication of HgBa2CuOy superconductor
Authors: Reddy E. Sudhakar , Murakami T. , Nakayama Y. , Shimoyama J. , Kishio K.
Published: March 2008

A process for the fabrication of textured Ba2CuO3 material with a microstructure similar to that of melt-processed YBa2Cu3Oy (Y123) superconductor is discussed. The Ba2CuO3 samples were melt processed with the intent to use them as textured precursors for processing of HgBa2CuOy superconductor. The microstructure formation of the Ba2CuO3 phase was studied by observing the samples being quenched from intermediate stages of a melt growth schedule. The microstructure of melt-processed Ba2CuO3 reveals randomly oriented large-sized grains, similar to that of melt textured Y123. Other important microstructural features observed were finely distributed properitectic BaO particles, the absence of the platelet gaps within the domains, and the presence of a different kind of twin structure. The conversion of melt textured Ba2CuO3 into superconducting HgBa2CuOy phase by a two-step process is discussed.
The hypersurfaces with conformal normal Gauss map in Hn+1 and S1n+1
Authors: Shi Shuguo
Published: March 2008

In this paper, we introduce the fourth fundamental forms for hypersurfaces in Hn+1 and space-like hypersurfaces in S1n+1, and discuss the conformality of the normal Gauss map of the hypersurfaces in Hn+1 and S1n+1. Particularly, we discuss the surfaces with conformal normal Gauss map in H³ and S³1, and prove a duality property. We give a Weierstrass representation formula for space-like surfaces in S³1 with conformal normal Gauss map. We also state the similar results for time-like surfaces in S³1. Some examples of surfaces in S³1 with conformal normal Gauss map are given and a fully nonlinear equation of Monge-Ampère type for the graphs in S³1 with conformal normal Gauss map is derived.
Câmara de ionização de placas paralelas para radiação-X de radiografia convencional e mamografia
Authors: Costa Alessandro Martins da , Caldas Linda V. E.
Published: March 2008

OBJETIVO: Desenvolver uma câmara de ionização de placas paralelas de dupla face para determinação de kerma no ar e taxa de kerma no ar em campos de radiação-X utilizados em radiografia convencional e mamografia. MATERIAIS E MÉTODOS: A câmara desenvolvida tem janelas de entrada de poliéster aluminizado, elétrodos internos e anéis de guarda de alumínio em uma face (face A) e de grafite na outra (face G). Neste trabalho foram testadas as características operacionais de linearidade, dependência angular e energética de resposta. RESULTADOS: A linearidade de resposta foi de 0,86% para a face A e de 0,92% para a face G. Para ângulos de incidência da radiação de 0° a ± 5°, a variação da resposta relativa foi menor que 0,8% para ambas as faces da câmara. A dependência energética de resposta foi de 0,8% para a face A nas qualidades de raios-X para diagnóstico convencional e de 2,4% para a face G da câmara nas qualidades de raios-X para mamografia. CONCLUSÃO: Esta câmara pode ser utilizada rotineiramente na determinação de kerma no ar e taxa de kerma no ar em feixes de raios-X utilizados em radiografia convencional e mamografia.
A new media optimizer based on the mean-variance model
Authors: Fernandez Pedro Jesus , Lauretto Marcelo de Souza , Pereira Carlos Alberto de Bragança , Stern Julio Michael
Published: March 2008

In the financial markets, there is a well established portfolio optimization model called generalized mean-variance model (or generalized Markowitz model). This model considers that a typical investor, while expecting returns to be high, also expects returns to be as certain as possible. In this paper we introduce a new media optimization system based on the mean-variance model, a novel approach in media planning. After presenting the model in its full generality, we discuss possible advantages of the mean-variance paradigm, such as its flexibility in modeling the optimization problem, its ability of dealing with many media performance indices - satisfying most of the media plan needs - and, most important, the property of diversifying the media portfolios in a natural way, without the need to set up ad hoc constraints to enforce diversification.
Controle de diabetes Mellitus e hipertensão arterial com grupos de intervenção educacional e terapêutica em seguimento ambulatorial de uma Unidade Básica de Saúde
Authors: Silva Terezinha Rodrigues , Feldmam Chaie , Lima Maria Helena A. , Nobre Moacyr R. Cuce , Domingues Rachel Z. L.
Published: March 2008

A educação em saúde, associada ao autocontrole dos níveis de pressão e/ou glicemia, à atividade física e à dieta alimentar, é importante instrumento para aumentar a procura por tratamento e controlar os índices de pacientes hipertensos e/ou diabéticos,. O conhecimento das doenças está relacionado à melhora da qualidade de vida, à redução do número de descompensações, ao menor número de internações hospitalares e à maior aceitação da doença. Na Unidade Básica de Saúde Vila Romana, São Paulo, foi proposta intervenção em uma população de pacientes diabéticos e hipertensos por meio de formação de grupos para ação educativa, seguimento regular, fornecimento de medicação, controles periódicos e atendimento de intercorrências. Nos primeiros 3 meses, ocorreram encontros mensais, seguidos de consultas periódicas, controle das doenças e dispensação da medicação por mais 27 meses. Com os 191 pacientes, foram formados grupos de hipertensos e grupos de diabéticos hipertensos. Comparando-se os resultados iniciais com os pós-intervenção, observou-se redução relativa de 42% e absoluta de 26% no número de pacientes com pressão moderada e grave. Para os diabéticos, a redução absoluta foi de 22%, para aqueles com glicemia superior a 200mg/dl, e aumento de 33%, para aqueles com níveis inferiores a 125mg/dl. Para pacientes dependentes do sistema oficial de saúde e do fornecimento da medicação, em grande parte idosos e pessoas com baixa escolaridade, embora não se tenha obtido no estudo o controle de todos os determinantes de adesão e o controle das doenças, a intervenção se mostrou eficiente. Sugere-se que seja institucionalizada.
Determinação de caminhos k-críticos em redes PERT
Authors: Contador José Luiz , Senne Edson Luiz França
Published: March 2008

Neste trabalho, apresenta-se um estudo sobre os principais métodos para identificar os caminhos de maior duração em redes PERT, denominados na literatura de caminhos k-críticos (quando k = 1, tem-se o caminho mais longo, conhecido tradicionalmente por caminho crítico; quando k = 2, tem-se o segundo caminho mais longo, e assim sucessivamente). São discutidos três algoritmos apresentados na literatura e propõe-se um novo procedimento, denominado algoritmo da folga mínima, que apresenta algumas vantagens sobre os anteriores. O comportamento do algoritmo da folga mínima, quando aplicado a redes PERT, é verificado por meio de simulação.
Testando teorias alternativas sobre a estrutura de capital nas empresas brasileiras
Authors: Medeiros Otávio Ribeiro de , Daher Cecílio Elias
Published: March 2008

O artigo documenta resultados de testes empíricos que envolvem dois modelos aplicados a estruturas de capital de empresas brasileiras. Os modelos testados foram desenvolvidos sob as duas principais teorias que competem entre si na literatura acadêmica pela determinação da estrutura de capital das empresas: a Static Tradeoff e a Pecking Order. A metodologia envolve a utilização de técnicas econométricas com dados em painel (panel data), buscando estabelecer qual das duas teorias possui maior poder explanatório para a amostra de empresas brasileiras. A análise utilizou três tipos de modelos: coeficientes comuns, efeitos fixos e efeitos aleatórios. Foram utilizados ainda diversos testes estatísticos para confirmar a robustez dos resultados. A amostra utilizada compreende empresas não-financeiras listadas nas bolsas de valores de São Paulo (BOVESPA e SOMA) no período de 1995 a 2002. A análise dos resultados encontrados levou à conclusão de que a chamada teoria Pecking Order, em sua forma semiforte, é a que melhor explicou a determinação da estrutura de capital das empresas brasileiras.
Uma abordagem dos reflexos contabéis decorrentes do cancelamento das despesas públicas dos restos a pagar da união (1999 - 2003)
Authors: Silva Maurício Corrêa Da
Published: March 2008

Este estudo objetivou analisar e evidenciar os reflexos contábeis decorrentes do cancelamento das despesas públicas dos restos a pagar da União. A identificação, a análise e a discussão foram possíveis a partir da coleta de dados das contas públicas, disponibilizadas pela Secretaria do Tesouro Nacional (STN), no período de 1999 a 2003. Definiu-se a hipótese nula de que os reflexos contábeis decorrentes do cancelamento das despesas dos restos a pagar não são significativos em relação às despesas liquidadas. Foram utilizadas as pesquisas exploratórias, bibliográficas, documental, qualitativa e quantitativa. Os resultados revelaram que o cancelamento das despesas públicas dos restos a pagar refletiu contabilmente no valor das despesas que foram consideradas liquidadas e divulgadas pelos poderes e órgãos da União: diminuição das despesas, incorporação de ativos a maior, estorno de exigibilidade, aumento de resultado do sistema financeiro.
Erosion of sediments beneath an oscillating cylinder
Authors: Narayanan R. , Aminzadeh A.
Published: March 2008

The depth of erosion of cohesionless sediments underneath horizontal circular cylinders that are oscillated periodically in still water was of primary interest in this study. In this investigation anthracite was used for the sediments. First the formation of vortex ripples was studied by oscillating a box containing anthracite on its own in still water without the cylinder. The geometrical characteristics of the ripples obtained compared well with those of other investigations. In the experimental range studied, the low density of sediments had no explicit influence on the features of the vortex ripples. The box filled with anthracite and the cylinder were oscillated together to perform periodic motion and the depth of erosion beneath the cylinder was measured. For the diameters of cylinder tested, the height of the vortex ripples formed on both sides of the cylinder was comparable with the depth of scour underneath the cylinder. The experimental results are categorised as clear water scour and live bed scour. For both cases, the relative scour depth was weakly dependent on the Shields parameter for Keulegan–Carpenter numbers less than about 30. For Keulegan–Carpenter numbers greater than about 30, it increased with the increasing value of the Shields parameter.
Oxygen free radical activity in the second stage of labor
Authors: Mongelli Max , Wang Chi Chiu , Wang Wei , Pang Calvin C. P. , Rogers Michael Scott
Published: March 2008

Objective. To assess fetal cellular injury arising from oxygen free radical activity in relation to the duration of the second stage of labor.

Patients and methods. Cord arterial pH, malondialdehyde and organic hydroperoxides levels were determined following vaginal delivery of 326 term singleton pregnancies. Of these, 35 (11%) received epidural analgesia. The length of the second stage was recorded from the time of full dilatation to delivery.

Results. Arterial cord pH, malondialdehyde and organic hydroperoxides were significantly correlated with duration of second stage of labor (r= −0.4492; r=0.2542; r=0.2244; respectively, p<0.001). The association of lipid peroxidation products with second stage duration was independent of cord pH. This correlation was unchanged when cases of operative delivery were excluded. However, the relationship lost statistical significance amongst cases who received epidurals.

Conclusions. The duration of the second stage is correlated with raised reactive oxygen species‐derived lipid peroxidation products. Caution should be exercised in the management of prolonged second stage of labor.
Ovarian volume in gynecologically healthy women using no contraception, or using IUD or oral contraception
Authors: Christensen Jeanette T. , Boldsen Jesper , Westergaard Jes G.
Published: March 2008

Objective. The aim of this study was to determine the ovarian volume by transvaginal ultrasonography in a gynecologically healthy population of women using no contraception, using intrauterine contraceptive device, or using oral contraceptive.

Materials and method. The study had a cross‐sectional design. The ovaries of 428 women aged 14 45 who contacted the family planning clinic in the county of Funen were examined. Most of the statistical analyses were carried out using standard techniques. However polynomial regression analysis was used to model ovarian volumes as a function of the day of cycle.

Results. No differences between the volumes of the right and the left ovary were found in any of the groups. Significant differences were found between the ovarian volumes of the three groups. The ovarian volumes were found to be largest in women using intrauterine contraceptive device, lesser in women using no contraception and smallest in women using oral contraception. A significant difference was found of the ovarian volumes throughout the menstrual cycle in women who were not using oral contraception. The ovarian volumes did not change throughout the menstrual cycle in women using oral contraception. In women not using oral contraception the largest ovary increased in volume from the start of the cycle to day 19, thereafter the volume declined. No evidence of any change of volume over the menstrual cycle was found in the smallest ovary and, for women using oral contraception, both ovaries. There was no correlation between age, height, weight, parity, and ovarian volume in any of the groups.

Conclusion. The ovarian volumes, in gynecologically healthy women using intrauterine contraceptive device, are larger than in women using no contraception. It appears that oral contraception reduces the volumes of both ovaries in all phases of the menstrual cycle to equal levels.
Stillbirths and rate of neonatal deaths in 76,761 postterm pregnancies in Sweden, 1982‐1991: a register study
Authors: Ingemarsson Ingemar , Källén Karin
Published: March 2008

Objective. To study stillbirths and neonatal mortality in the postterm period.

Design. Register study of information obtained from the Swedish Medical Birth Registry (MBR), National Board of Health and Welfare, Stockholm.

Methods. Singleton pregnancies with deliveries occurring between 1982 and 1991 were selected involving 914,702 women (of whom 76,761 had a postterm pregnancy continuing beyond the 42nd week of amenorrhea). All 2,043 records of dead infants were scrutinized before analysis of neonatal deaths. Stratification was made for year of birth, maternal age, and parity.

Results. Generally, the rates of stillbirths and neonatal deaths were low. The stillbirth rate was highest for primiparas at 38 completed weeks (2.72‰), lowest at 40 weeks (1.23‰), then increasing to 2.26% in the postterm period. The difference v. multiparas was significant from 41 weeks onwards. Neonatal mortality was increased at 41 completed weeks for primiparas, but for multiparas it changed significantly first in the postterm period. The OR for a primipara to have an intrauterine death increased from 1.50 at 41 weeks (1.0 at 40 weeks) to 1.79 at 42 weeks and beyond. The OR for multiparas showed no sign of increase as gestation progressed.

Conclusions. The results of this study indicate an increased risk of stillbirth with gestational age for primiparas but not for multiparas. The neonatal death rate was increased for both primiparas and multiparas (after 42 completed weeks).
Behavioral Toxicology of Volatile Organic Solvents. III. Acute and Subacute Effects of Carbon Disulfide Exposure on the Behavior of Mice
Authors: Liang You-Xin , Glowa John R. , Dews P. B.
Published: March 2008

The effects of exposure to carbon disulfide (CS2) were studied on two different behavioral responses in mice. One response was the interruption of a single light beam passing immediately behind a small hole in the wall of the mouse chamber. The other response was the consecutive interruption of each of three radial light beams spaced around a circular runway. Both responses were maintained under an FI 60-sec schedule of milk presentation. Acute, cumulative concentration-effect functions were determined by increasing, stepwise, the concentration of CS2 in the chamber until responding was abolished. Although the level of physical activity required by the two responses was quite different, the acute effects of CS2 on each were quantitatively similar: a concentration of 120 ppm was without effect, 580 ppm decreased responding in most mice, to as low as 0.55 of control levels, 2200 ppm decreased responding in all mice, and 3700 ppm abolished responding. Recovery from these acute effects was slow; following cumulative exposures which abolished responding, recovery to 0.50 of the control level of responding took more than 4 hr, and full recovery required 6 hr. With repeated daily exposure to CS2, the cumulative effect on both types of responding depended upon the concentration and the duration of the exposure. No effect was seen with either response until the fifth day of exposure to 260 ppm; 580 ppm decreased responding progressively during most daily exposures but the overall decrease was not different on successive days; 840 ppm decreased responding progressively during daily exposures and the decrease was also progressively greater on successive days. Daily control performances before exposure were unaffected during repeated exposure, so the manifest effects of these levels of CS2 did not appear to last as long as 18 hr.
Utility of Kinetic, Dynamic, and Metabolic Data in Nonclinical Pharmacology/Toxicology Studies
Authors: Weissinger Judi
Published: March 2008

Kinetic, dynamic, and metabolic data can be used to predict the appropriate studies, doses, duration, route of administration, species, and dosage interval in toxicology studies coordinated with drug development. These data are used to predict starting and maximal doses in human studies, and when evaluated in conjunction with the data obtained in human pharmacokinetic studies, serve as an index for animal to human comparisons and extrapolations. The optimal use of kinetic and dynamic information in standard pharmacologic and toxicologic studies will be presented. Reference will be made to problems encountered in the absence of these data and protocol development advantages where these data are incorporated. Developmental of pharmaceuticals, without incorporating kinetic and dynamic information, is currently associated with more costly, more time consuming, less utilizable knowledge and subsequent studies are often needed to explain anomalous results.
Toxicological Basis for Drinking Water: Unreasonable Risk to Health Values
Authors: Zavaleta Jennifer Orme
Published: March 2008

The U.S. Environmental Protection Agency (EPA) administers the Safe Drinking Water Act (SDWA) to ensure that the water obtained from a public water supply is safe to drink. Under the SDWA, EPA establishes enforceable maximum contaminant levels (MCLs) for contaminants that may have an adverse health effect and are known or anticipated to occur in water. Occasionally, public water supplies are unable to meet the MCL at the time it becomes enforceable. The SDWA allows public water supplies to apply to the State for a temporary variance or exemption from an MCL(s) as long as the concentration of the contaminant(s) exceeding the MCL(s) does not result in an unreasonable risk to human health. EPA has developed guidance to assist States in determining what level above the MCL presents an unreasonable health risk. In developing this guidance, the toxicity exhibited by each regulated contaminant is evaluated individually. Consideration is also given to the available risk assessments (short-term and long-term) for each contaminant, comparing carcinogenic risks with noncarcinogenic assessments. Other factors that may be considered on a contaminant by contaminant basis include for example, past exposure and expected duration of the variance or exemption period, population sensitivity, and volatilization of the contaminant from drinking water.
Flashbulb memories for expected events: a test of the emotional‐integrative model
Authors: Curci Antonietta , Luminet Olivier
Published: March 2008

Flashbulb memories (FBMs) are vivid, long‐lasting and consistent recollections for the reception context of shocking and unexpected public news. Only a few studies have assessed FBMs for predictable events. In the present study the emotional‐integrative model is considered to account for FBMs for an expected event, that is, the death of President Mitterrand, across two national groups, that are, French and Belgian citizens. Results showed that FBMs can develop for an expected event; they are affected by its emotional impact and subsequent rehearsal, while surprise did not play a role in their formation. The emotional‐integrative model was confirmed as a promising tool to model datasets on FBMs. It holds for both subsamples, with a better parsimony for Belgian respondents' data. Implications for the debate about the nature of FBMs are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Palladium Supported on an Acidic Resin: A Unique Bifunctional Catalyst for the Continuous Catalytic Hydrogenation of Organic Compounds in Supercritical Carbon Dioxide
Authors: Seki Tsunetake , Grunwaldt Jan‐Dierk , van Vegten Niels , Baiker Alfons
Published: March 2008

1% Palladium‐doped acidic resin (Amberlyst® 15; styrene‐divinylbenzene matrix with sulfonic acid groups) is shown to be a highly active catalyst for the continuous catalytic hydrogenation of CC bonds in supercritical carbon dioxide (scCO2) without affecting CO bonds. This 1% Pd/Amberlyst‐15 catalyst promotes the industrially important selective formation of 2‐ethylhexanal from crotonaldehyde in a “one‐pot” pathway involving hydrogenation and aldol condensation with a number of merits. The selectivity behavior of 1% Pd/Amberlyst‐15 is strikingly different compared to that of 1% Pd/C and 1% Pd/Al2O3 due to its prominent bifunctional nature based on sulfonic acid groups adjacent to metallic Pd sites. Hybrid “[Pdn–H]+” sites are suggested to act as both metal and acid sites promoting the bifunctional catalysis.
Extracorporeal photopheresis: Lighting the way to immunomodulation
Authors: Babic Aleksandar M.
Published: March 2008

Photopheresis, initially established as an effective treatment of cutaneous T‐cell lymphoma, has in recent years also been used to treat chronic graft vs. host disease, heart transplant rejection, and several other conditions requiring immunosuppression. Despite reported beneficial results of this procedure in treatment of various conditions, randomized controlled clinical trials are lacking for the majority of suggested indications. Furthermore, the mechanisms of action of this procedure are still unclear. Deeper understanding of the molecular basis of photopheresis‐based immunomodulation will allow better selection of patients to be treated and will facilitate development of novel, minimally toxic immunomodulatory treatments. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Nanomaterialien für wiederaufladbare Lithiumbatterien
Authors: Bruce Peter G. , Scrosati Bruno , Tarascon Jean‐Marie
Published: March 2008

Energiespeicherung ist heute wichtiger denn je. Künftige Generationen von wiederaufladbaren Lithiumbatterien müssen tragbare Elektrogeräte (Mobiltelefone, Laptops etc.) mit Energie versorgen, Elektrizität aus erneuerbaren Energiequellen speichern und neue Hybrid‐Automobile mit der nötigen Energie versorgen können. Zur Erhöhung der Energie‐ und Stromdichte, die für die zukünftigen Herausforderungen bei der Energiespeicherung essenziell ist, muss eine neue (Nano‐)Materialchemie entwickelt werden. Wir müssen Wege finden, Nanomaterialien mit neuen Eigenschaften oder Eigenschaftskombinationen als Elektroden und Elektrolyte für Lithiumbatterien zu synthetisieren. In diesem Aufsatz beleuchten wir aktuelle Fortschritte auf dem Gebiet der Nanomaterialien, besonders nanostrukturierter Materialien, für wiederaufladbare Lithiumionenbatterien.
The thermal conductivity of Nylon 6/clay nanocomposites
Authors: Zhou Hu , Zhang Shimin , Yang Mingshu
Published: March 2008

Nylon 6/clay nanocomposites (NCNs) of different clay loadings are prepared by melt compounding. The effects of clay loading and dispersion on the thermal conductivity of NCNs are investigated using XRD, TEM, DSC, and POM. The results show that the thermal conductivity of the exfoliated NCNs decreases with an increase of clay content; but the thermal conductivity of the intercalated NCNs does not decrease, indeed, it increase markedly at high clay content. Such results observed in the exfoliated NCNs are opposite to the expectation of the classic Maxwell thermal conduction model. The further investigations indicate that such decrease observed in the exfoliated NCNs is due mainly to the exfoliation of clay layers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Soy‐based polyurethanes by nonisocyanate route
Authors: Javni Ivan , Hong Doo Pyo , Petrović Zoran S.
Published: March 2008

Polyurethanes by a nonisocyanate route were prepared by reacting carbonated soybean oil with different diamines. The effect of amine structure and carbonate to amine ratio on polyurethane structure and mechanical, physical, and swelling properties was studied. The reactants 1,2‐ethylenediamine, 1,4‐butylenediamine, and 1,6‐hexamethylenediamine were used with the carbonate to amine ratio of 1 : 0.5, 1 : 1, and 1 : 2. It was found that along with urethane formation, the amine group reacted with ester groups to form amides. All amines produced elastomeric polyurethanes with glass transitions between 0 and 40°C and hardness between 40 and 90 Shore A. The reaction of epoxidized soybean oil with carbon dioxide was optimized resulting in complete conversion of epoxy to cyclic carbonate groups ending in polyurethanes with higher crosslinking density and much higher tensile strength than previously reported for similar polyurethanes. Swelling in toluene and water depended on crosslinking density and the polarity of polyurethane networks controlled by the cyclic carbonate‐to‐amine‐ratio. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of interpenetration polymer network films based on poly(vinyl alcohol) and poly(acrylic acid) for drug delivery
Authors: Yue Yu‐Mei , Xu Kun , Liu Xiao‐Guang , Chen Qiang , Sheng Xiang , Wang Pi‐Xin
Published: March 2008

A series of full interpenetrating polymer network (full‐IPN) films of poly(acrylic acid) (PAA)/poly (vinyl alcohol) (PVA) were prepared by radical solution polymerization and sequential IPN technology. Attenuated total reflectance‐Fourier transform infrared spectroscopy, swelling properties, mechanical properties, morphology, and glass transition temperature of the films were investigated. FTIR spectra analysis showed that new interaction hydrogen bonds between PVA and PAA were formed. Swelling property of the films in distilled water and different pH buffer solution was studied. Swelling ratio increased with increasing PAA content of IPN films in all media, and swelling ratio decreased with increasing PVA crosslink degree. Tensile strength and elongation at break related not only to the constitution of IPNs but also to the swelling ratio of IPNs. Mechanical property of glutaraldehyde (0.5%) for poly(vinyl alcohol) crosslinking was better than that of glutaraldehyde (1.0%). DSC of the IPN films showed only a single glass transition temperature (Tg) for each sample, and Tg data showed a linear relationship with network composition. Morphology was observed a homogeneous structure, indicating the good compatibility and miscibility between PAA and PVA. Potential application of the IPN films in controlled drug delivery was also examined using crystal violet as a model drug. The release rate of the drug was higher at 37°C than 25°C for all IPNs and also increased slightly with decreasing of poly(acrylic acid) content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Professional storytelling in clinical dental anatomy teaching
Authors: Kieser Jules , Livingstone Vicki , Meldrum Alison
Published: March 2008

The aim of the present work was to see if storytelling in a clinical dental anatomy course would increase student satisfaction. We enhanced teaching by spontaneous storytelling in problem‐based learning, in half of the third‐year dentistry class. At the end of the course, we administered an anonymous questionnaire to the students in the class, consisting of 12 questions that students had to answer on a Likert scale of 1–5. An overall satisfaction score was obtained and we used a linear mixed model to compare differences in satisfaction between the two groups, with “group” as the fixed effect. We also conducted an exploratory factor analysis of the responses to investigate whether there were distinct constructs within the data. Overall satisfaction is high, with students “with stories” having higher satisfaction than those “without stories.” The former group consistently gives higher satisfaction scores, regardless of which question is being asked. Factor analysis provides evidence that storytelling nurtures reflective learning, while students work on their clinical anatomy problems. Anat Sci Ed 1:84–89, 2008. © 2008 American Association of Anatomists.
Effects of oral kaempferol on the pharmacokinetics of tamoxifen and one of its metabolites, 4‐hydroxytamoxifen, after oral administration of tamoxifen to rats
Authors: Piao Yongji , Shin Sang‐Chul , Choi Jun‐Shik
Published: March 2008

It has been reported that tamoxifen is a substrate of P‐glycoprotein (P‐gp) and microsomal cytochrome P450 (CYP) 3A, and kaempferol is an inhibitor of P‐gp and CYP3A. Hence, it could be expected that kaempferol would affect the pharmacokinetics of tamoxifen. Thus, tamoxifen was administered orally (10 mg/kg) without or with oral kaempferol (2.5 and 10 mg/kg). In the presence of kaempferol, the total area under the plasma concentration–time curve from time zero to time infinity (AUC) of tamoxifen was significantly greater, Cmax was significantly higher and F was considerably greater than those without kaempferol. The enhanced bioavailability of oral tamoxifen by oral kaempferol could have been due to an inhibition of CYP3A and P‐gp by kaempferol. The presence of kaempferol did not alter the pharmacokinetic parameters of a metabolite of tamoxifen, 4‐hydroxytamoxifen. This could have been because the contribution of CYP3A to the formation of 4‐hydroxytamoxifen is not considerable in rats. Copyright © 2008 John Wiley & Sons, Ltd.
Decline in the prevalence of neural tube defects following folic acid fortification and its cost‐benefit in South Africa
Authors: Sayed Abdul‐Rauf , Bourne David , Pattinson Robert , Nixon Jo , Henderson Bertram
Published: March 2008

BACKGROUND: In October 2003 South Africa embarked on a program of folic acid fortification of staple foods. We measured the change in prevalence of NTDs before and after fortification and assessed the cost benefit of this primary health care intervention. METHODS: Since the beginning of 2002 an ecological study was conducted among 12 public hospitals in four provinces of South Africa. NTDs as well as other birth defect rates were reported before and after fortification. Mortality data were also collected from two independent sources. RESULTS: This study shows a significant decline in the prevalence of NTDs following folic acid fortification in South Africa. A decline of 30.5% was observed, from 1.41 to 0.98 per 1,000 births (RR = 0.69; 95% CI: 0.49–0.98; p = .0379). The cost benefit ratio in averting NTDs was 46 to 1. Spina bifida showed a significant decline of 41.6% compared to 10.9% for anencephaly. Additionally, oro‐facial clefts showed no significant decline (5.7%). An independent perinatal mortality surveillance system also shows a significant decline (65.9%) in NTD perinatal deaths, and in NTD infant mortality (38.8%). CONCLUSIONS: The decrease in NTD rates postfortification is consistent with decreases observed in other countries that have fortified their food supplies. This is the first time this has been observed in a predominantly African population. The economic benefit flowing from the prevention of NTDs greatly exceeds the costs of implementing folic acid fortification. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Mortality rates in subjects with fetal alcohol spectrum disorders and their siblings
Authors: Burd Larry , Klug Marilyn G. , Bueling Robyn , Martsolf John , Olson Meredith , Kerbeshian Jacob
Published: March 2008

BACKGROUND: Our objective was to estimate the mortality rate in subjects with fetal alcohol spectrum disorders (FASD) and their siblings whose FASD status was unknown. METHODS: We used the state FASD Registry to link subjects with FASD to a North Dakota birth certificate. We were able to link 304 of 486 cases (63%). We used the birth certificates to identify the mother and children born to the mother (siblings). We then searched for death certificates for both the FASD cases and their siblings. We then calculated the annual and age‐adjusted mortality rates for the siblings of the Registry cases and compared them with mortality rates from North Dakota. RESULTS: The FASD case mortality rate was 2.4%, with a 4.5% mortality rate for their sibings, accounting for 14% of all deaths when compared to the North Dakota residents matched by age and year of death. The sibling deaths accounted for 21.5% of all cause mortality matched by age and year of death. The age‐standardized mortality ratios were 4.9 for the FASD cases and 2.6 for their siblings whose FASD status was unknown. CONCLUSIONS: Mortality rates for FASD cases and their siblings were increased and represent a substantial proportion of all cause mortality in North Dakota. Prevention of FASD may be a useful strategy to decrease mortality. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Use of local rank‐based spatial information for resolution of spectroscopic images
Authors: de Juan Anna , Maeder Marcel , Hancewicz Thomas , Tauler Romà
Published: March 2008

Spectroscopic images are singular chemical measurements that enclose chemical and spatial information about samples. Resolution of spectroscopic images is focused on the recovery of the pure spectra and distribution maps of the image constituents from the sole raw spectroscopic measurement. In image resolution, constraints are generally limited to non‐negativity and the spatial information is generally not used. Local rank analysis methods have been adapted to describe the local spatial complexity of an image, providing specific pixel information. This local rank information combined with reference spectral information allows the identification of absent compounds in pixels with low compound overlap. The introduction of this information in the resolution process under the form of constraints helps to increase the performance of the resolution method and to decrease the ambiguity linked to the final solutions. Copyright © 2008 John Wiley & Sons, Ltd.
One‐Pot Synthesis of Nitrones from Primary Amines and Aldehydes Catalyzed by Methyltrioxorhenium
Authors: Cardona Francesca , Bonanni Marco , Soldaini Gianluca , Goti Andrea
Published: March 2008

One‐pot condensation/oxidation of primary amines and aldehydes using urea–hydrogen peroxide (UHP) as the stoichiometric oxidant in the presence of methyltrioxorhenium (MTO) as catalyst affords nitrones in a simple and regioselective manner. UHP is a practical and safe source of H2O2, and its use here instead of aqueous H2O2 solutions also simplifies greatly the workup procedure as extractions with organic solvents can be avoided. Typically, at the end of the reaction the solid urea is simply filtered off. From a sustainability point of view, this one‐pot synthesis is simple to perform, takes place under mild conditions, has a high atom economy, and releases water as the only by‐product.
Enhanced sensitivity to DNA damage induced by cooking oil fumes in human OGG1 deficient cells
Authors: Wu Mei , Che Wangjun , Zhang Zunzhen
Published: March 2008

Cooking oil fumes (COFs) have been implicated as an important nonsmoking risk factor of lung cancer in Chinese women. However, the molecular mechanism of COFs‐induced carcinogenicity remains unknown. To understand the molecular basis underlying COFs‐induced cytotoxicity and genotoxicity as well as the roles of hOGG1 in the repair of COFs‐induced DNA damage, a human lung cancer cell line with hOGG1 deficiency, A549‐R was established by using a ribozyme gene targeting technique that specifically knockdowned hOGG1 in A549 lung adenocarcinoma cells. MTT and comet assays were employed to examine cell viability and DNA damage/repair, respectively, in A549‐R and A549 cell lines treated with COF condensate (COFC). RT‐PCR and Western blot results showed that the expression of hOGG1 in A549‐R cell line was significantly decreased compared with that in A549 cell line. The concentration of COFC that inhibited cell growth by 50% (the IC50) in the A549‐R cell line was much lower than that in the A549 cell line, and more COFC‐induced DNA damage was detected in the A549‐R cell line. The time course study of DNA repair demonstrated delayed repair kinetics in the A549‐R cell line, suggesting a decreased cellular damage repair capacity. Our results showed that hOGG1 deficiency enhanced cellular sensitivity to DNA damage caused by COFC. The results further indicate that hOGG1 plays an important role in repairing COF‐induced DNA damage. Our study suggests that COFs may lead to DNA damage that is subjected to hOGG1‐mediated repair pathways, and oxidative DNA damage may be involved in COF‐induced carcinogenesis. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Admissible Orders of Jordan Loops
Authors: Kinyon Michael K. , Pula Kyle , Vojtěchovský Petr
Published: March 2008

A commutative loop is Jordan if it satisfies the identity x2(yx) = (x2y)x. Using an amalgam construction and its generalizations, we prove that a nonassociative Jordan loop of order n exists if and only if n≧ 6 and n≠ 9. We also consider whether powers of elements in Jordan loops are well‐defined, and we construct an infinite family of finite simple nonassociative Jordan loops. © 2008 Wiley Periodicals, Inc. J Combin Designs 17: 103–118, 2009
Direct sums of balanced functions, perfect nonlinear functions, and orthogonal cocycles
Authors: LeBel Alain , Horadam K. J.
Published: March 2008

Determining if a direct sum of functions inherits nonlinearity properties from its direct summands is a subtle problem. Here, we correct a statement by Nyberg on inheritance of balance and we use a connection between balanced derivatives and orthogonal cocycles to generalize Nyberg's result to orthogonal cocycles. We obtain a new search criterion for PN functions and orthogonal cocycles mapping to non‐cyclic abelian groups and use it to find all the orthogonal cocycles over Z2t, 2 ≤ t ≤ 4. We conjecture that any orthogonal cocycle over Z2t, t ≥ 2, must be multiplicative. © 2008 Wiley Periodicals, Inc. J Combin Designs 16: 173–181, 2008
Experimental evaluation of alternative fermentation media for L‐lactic acid production from apple pomace
Authors: Gullón Beatriz , Alonso José Luis , Parajó Juan Carlos
Published: March 2008

BACKGROUND: A variety of nitrogen sources were tested for lactic acid production. Corn steep liquor is a low‐cost by‐product that could replace some of the expensive nutrients of the general lactobacilli media. This work deals with the optimisation of the composition of a low‐cost medium for lactic acid production from apple pomace by Lactobacillus rhamnosus CECT‐288.

RESULTS: Corn steep liquor (CSL) and yeast extract (YE) were evaluated as nutrient sources for lactic acid production from apple pomace. In comparison with media containing CSL, experiments with YE led to higher volumetric productivities but lower lactic acid concentrations and product yields. The presence of YE increased the production of acetic acid. In media containing 0.2 g CSL g−1 potential sugars, 29.5 g lactic acid L−1 was obtained after 24 h, at good yield (35.5 g per 100 g dry apple pomace) and productivity (1.23 g L−1 h−1), with a lactic acid/acetic acid mass ratio of 98 g g−1.

CONCLUSION: The experimental results proved that CSL is a suitable nutrient source for lactic acid production from apple pomace, even though the volumetric productivity was lower than in experiments employing YE. Considered as a nutrient supplement, CSL presents advantages over YE not only in terms of cost but also in terms of product yield, final lactic acid concentration and lactic acid/acetic acid mass ratio. The utilisation of apple pomace as the raw material and CSL as the sole nutrient source (both cheap by‐products) enables the production of lactic acid by an economical, environmentally friendly process. Copyright © 2008 Society of Chemical Industry
Biosorption of heavy metals from aqueous solution using modified activated carbon: comparison of linear and nonlinear methods
Authors: Lai Yi‐Ling , Annadurai Gurusamy , Huang Fu‐Chang , Lee Jiunn‐Fwu
Published: March 2008

BACKGROUND: Biosorption of heavy metals from aqueous solution by modified activated carbon with Phanerochaete chrysosporium immobilised in Ca‐alginate beads was investigated using a batch system and comparison of linear and nonlinear methods.

RESULTS: The amount of Cu(II), Zn(II) and Pb(II) ion sorption by the beads was as follows: activated carbon with P. chrysosporium immobilised in Ca‐alginate beads (ACFCA) (193.4, 181.8, 136.6 mg g−1) > activated carbon immobilised in Ca‐alginate beads (ACCA) (174.8, 162.0, 130.7 mg g−1) > P. chrysosporium (F) (148.8, 125.6, 120.4 mg g−1) > activated carbon (AC) (138.8, 112.3, 109.3 mg g−1) > plain Ca‐alginate beads (PCA) (125.4, 105.2, 98.2 mg g−1). The widely used Langmuir and Freundlich isotherm models were utilised to describe the biosorption equilibrium process.

CONCLUSION: The results of this study suggest that the immobilisation of modified activated carbon with P. chrysosporium in Ca‐alginate beads is suitable for a batch system. The isotherm parameters were estimated using linear and nonlinear regression analyses. The surface charge density of the biosorbents varied with the pH of the medium; the maximum biosorption of heavy metal ions on the biosorbents was obtained when the pH was between 5.6 and 7.4. Copyright © 2008 Society of Chemical Industry
6‐[123I]Iodo‐2‐[[4‐(2‐methoxyphenyl) piperazin‐1‐yl]methyl]imidazo[1,2‐a]pyridine as potential SPECT agent for imaging dopamine D4receptor: synthesis andin vivoevaluation in a nonhuman primate
Authors: Alagille David , Koren Andrei O. , Kudej Greg , Staley Julie , Cosgrove Kelly , Seibyl John , Tamagnan Gilles D.
Published: March 2008

The dopamine D4receptor subtype has drawn considerable attention due to its potential implication in schizophrenia and erectile dysfunction. 6‐[123I]Iodo‐2‐[[4‐(2‐methoxyphenyl)piperazin‐1‐yl]methyl]imidazo[1,2‐a]pyridine [123I]‐1, a potent and selective new dopamine D4agonist, was synthesized by classical iododestannylation using sodium [123I]iodide and chloramine‐T. Radiolabeling yield varied from 34 to 38% with a radiochemical purity exceeding 99%. Despite a goodin vitroprofile,in vivoevaluation of this radioligand in baboon showed no brain uptake after i.v. injection. Copyright © 2008 John Wiley & Sons, Ltd.