bluuebunny/crossref_metadata_2025 huggingface dataset:
Histórico das tentativas de liberação da venda de medicamentos em estabelecimentos leigos no Brasil a partir da implantação do Plano Real
Authors: Melo Eduardo Borges de , Teixeira Jorge Juarez Vieira , Mânica Graciele Cristiane More
Published: October 2007

Apesar de ilegal, a prática da venda de medicamentos em locais inadequados e não permitidos por lei, como armazéns e supermercados, sempre foi bastante comum no Brasil. A Medida Provisória (MP) 592/94, que implantou o Plano Real, liberou a venda de medicamentos anódinos nestes estabelecimentos; porém, este artigo foi suprimido quando a mesma foi convertida na Lei 9.069/95. A partir daí, iniciou-se uma série de tentativas de legalização deste comércio, que só se encerraram em 2004, com a proibição pelo STJ de tal comercialização. Mesmo assim, o comércio continua a ocorrer de forma ilegal. Este trabalho apresenta um histórico dos acontecimentos compreendidos entre 1994 e 2006, visando fornecer um material de atualização ao farmacêutico, acadêmicos e pesquisadores da área, devido à escassez de material bibliográfico sobre este tema específico.
Comunicação no controle de risco à saúde e segurança na sociedade contemporânea: uma abordagem interdisciplinar
Authors: Rangel-S Maria Ligia
Published: October 2007

Este ensaio objetiva discutir a comunicação enquanto tecnologia para o controle do risco, proteção e promoção da saúde e segurança, no contexto da "sociedade de risco". Como um componente da Análise de Risco, a comunicação do risco é uma tecnologia que comparece na literatura sobre risco, com objetivos, princípios e modelos bem definidos. Esses aspectos são descritos e problematizados, considerando-se as múltiplas racionalidades em torno dos riscos na cultura e as várias dimensões que envolvem a regulação e controle do mesmo na chamada "modernidade tardia". Considera-se também a complexidade do processo de comunicação, informada pelo debate teórico-metodológico deste campo. Para apreciar o verdadeiro valor do campo da comunicação para o controle de risco, proteção e promoção da saúde, o artigo oferece uma síntese das teorias de comunicação que sustentam o debate desse tema, e propõe aproximações críticas a modelos que incluem as dimensões do poder e da cultura, no contexto da sociedade capitalista.
Processo de decisão do uso da informação
Authors: Lira Waleska Silveira , Cândido Gesinaldo Ataíde , Araújo Geraldo Maciel de , Barros Marcelo Alves de
Published: October 2007

Este artigo tem como objetivo propor um modelo do processo de decisão do uso da informação, a partir da análise das diferentes abordagens da busca e uso da informação. Para tanto, foi realizada uma pesquisa exploratória, que se divide em uma etapa qualitativa, na qual se buscou identificar os estágios do processo de decisão do uso da informação, e uma etapa quantitativa, que possibilitou a identificação dos fatores influenciadores deste processo. O modelo proposto apresenta quatro estágios: o reconhecimento da necessidade de informação, a busca de informação, a decisão do uso da informação e a avaliação da decisão do uso da informação. Os resultados indicam que os fatores como tecnologia, pressões externas, comodidade, variedade, ambiente, qualidade da informação, credibilidade, motivos pessoais e profissionais, exercem influência no comportamento dos usuários quando estes decidem usar a informação para tomar decisões.
A classificação de acervos bibliográficos em bibliotecas de órgãos do judiciário: bens de consumo ou permanentes?
Authors: Medeiros Nilcéia Lage , Melo Alfredo Alves de Oliveira , Jeunon Ester Eliane
Published: October 2007

O artigo 18 da Lei nº 10.753/2003, estabeleceu que, com a finalidade de controlar os bens patrimoniais das bibliotecas públicas, "o livro não é considerado material permanente". Foi realizada uma pesquisa no período de 26/02/2007 a 21/03/2007 objetivando analisar o que está sendo considerado na classificação dos acervos bibliográficos em bibliotecas de 33 órgãos do judiciário brasileiros (STF, STJ, CJF, TRFs, TST e TRTs), sendo que 22 deles colaboraram. Concluiu-se que a referida lei não deveria ter sido objeto de "conflitos e dilemas" já que bibliotecas destes órgãos são enquadradas como especializadas e, assim sendo, os livros devem ser classificados como bens permanentes. Também a STN emitiu parecer em 2003 reproduzindo o conceito de biblioteca pública e dispondo o que as bibliotecas que não se enquadram como públicas deveriam observar para a classificação. Ressalta-se que tal entendimento está claro, mas não está explicitado nem na lei e nem no parecer em questão. Detectou-se a necessidade de sanar as dúvidas e padronizar procedimentos relativos à classificação de acervos das bibliotecas desses órgãos, principalmente para os materiais indispensáveis ao desenvolvimento técnico gerencial específico ou à execução das atividades. Comunga-se com o disposto na Mensagem nº 767192/2003, que devem ser observadas as peculiaridades e finalidades dos bens com vistas à classificação.
As rasuras da modernidade na poesia de Sebastião Uchoa Leite
Authors: Andrade Paulo
Published: October 2007

A obra de Sebastião Uchoa Leite é circunscrita num campo de tensão - desvio e aproximação - com a tradição, o que impossibilita a demarcação de limites a quem busca traçar um contorno da sua poética. A inegável identificação com os mestres modernistas não significa a ampliação de tais modelos; ao contrário, estes são contaminados pelo entrecruzamento das mais diversas referências. A indecidível ambigüidade decorre do fato de que o poeta não demarca nenhum território espaciotemporal, nem norteia direções definidas. Trata-se de um projeto textual híbrido, de travessia, cujo percurso nômade faz transitar, lado a lado, discursos referenciais da tradição e do mundo contemporâneo.
Fonte investigadora em Educação: registros do banco de teses da CAPES
Authors: Vieira Renata de Almeida , Maciel Lizete Shizue Bomura
Published: October 2007

Apresenta-se neste artigo o resultado de uma investigação realizada no Banco de Teses CAPES - Resumos, banco de dados multidisciplinar disponibilizado via internet pela Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES. Ao congregar informações básicas de pesquisas de pós-graduação stricto sensu - mestrado e doutorado - das diversas áreas e subáreas do conhecimento humano, desenvolvidas em Instituições de Ensino Superior - IES - públicas e particulares de todo o território nacional e defendidas a partir de 1987, esse banco, por meio de resumos, constitui-se em uma fonte de pesquisa abrangente, bem como em um instrumento relevante de divulgação do conhecimento científico brasileiro. Considerada tal abrangência e relevância, ao perceber em consulta às suas bases algumas incongruências nos dados recuperados pelo sistema, bem como falta de informações senão importantes, mas efetivamente necessárias àqueles que pesquisam ou buscam informações preliminares de estudos, efetuou-se uma investigação exploratória em uma amostra de seus registros, a qual se pautou em pesquisa documental e foi iniciada por meio da palavra-chave preconceito. Fruto dessa exploração é o presente ensaio, que tem por objetivo apresentar um panorama das constatações feitas acerca do aspecto formal dos registros e das estrutura dos resumos constantes nesse banco. Objetiva-se, também, marcar a importância de se realizar estudos que contribuam para o fomento de um debate crítico-reflexivo que implique ações resolutivas dos problemas constatados.
Physically Based Estimation of Soil Water Retention from Textural Data: General Framework, New Models, and Streamlined Existing Models
Authors: Nimmo John R. , Herkelrath William N. , Laguna Luna Ana M.
Published: October 2007

Numerous models are in widespread use for the estimation of soil water retention from more easily measured textural data. Improved models are needed for better prediction and wider applicability. We developed a basic framework from which new and existing models can be derived to facilitate improvements. Starting from the assumption that every particle has a characteristic dimension R associated uniquely with a matric pressure ψ and that the form of the ψ–R relation is the defining characteristic of each model, this framework leads to particular models by specification of geometric relationships between pores and particles. Typical assumptions are that particles are spheres, pores are cylinders with volume equal to the associated particle volume times the void ratio, and that the capillary inverse proportionality between radius and matric pressure is valid. Examples include fixed‐pore‐shape and fixed‐pore‐length models. We also developed alternative versions of the model of Arya and Paris that eliminate its interval‐size dependence and other problems. The alternative models are calculable by direct application of algebraic formulas rather than manipulation of data tables and intermediate results, and they easily combine with other models (e.g., incorporating structural effects) that are formulated on a continuous basis. Additionally, we developed a family of models based on the same pore geometry as the widely used unsaturated hydraulic conductivity model of Mualem. Predictions of measurements for different suitable media show that some of the models provide consistently good results and can be chosen based on ease of calculations and other factors.
Flow and High Explosives Transport in a Semiarid Mesa in New Mexico, USA
Authors: Newman Brent D. , Hickmott Donald D. , Gram Peter
Published: October 2007

Outfalls from high explosives (HE) production facilities at Los Alamos National Laboratory discharged HE‐contaminated waters onto a semiarid mesa on the Pajarito Plateau for about 50 yr. As part of an initial hydrogeologic characterization to examine the impact of HE contamination, four boreholes were drilled into the vadose zone to depths between 38.1 and 63.3 m. The study objectives were to characterize contaminant nature and extent and to identify potential source areas and transport pathways. Besides providing an example of HE transport in the vadose zone, this study shows the value of integrating chloride and stable isotope tracer approaches with contaminant distribution information, and it provides insights on semiarid vadose zone behavior in the little studied, but widespread ponderosa pine forests of the American Southwest. Chloride‐based vadose zone residence time estimates (1950–6080 yr) suggest that downward flow and transport over much of the mesa is limited. However, the presence of HE‐contaminated transient saturated zones in two boreholes indicates that localized fast pathways also occur. Stable isotope data (δ18O and δD) suggest that the source areas for contamination are former HE outfall discharge ponds that provide focused recharge to the transient saturated zones.
Water Retention Models for Scale‐Variant and Scale‐Invariant Drainage of Mass Prefractal Porous Media
Authors: Cihan Abdullah , Perfect Ed , Tyner John S.
Published: October 2007

This research describes the development of water retention models incorporating the effects of partial drainage in random mass prefractal porous media. The pore‐size distribution, as well as the connectivity of pores, determines the drained pore volume as a function of suction. The concept of probability of drainage leads to a general scale‐variant drainage model (GM) in which the proportion of pores that drain at a given suction level is dependent on the fractal dimension of the drained pore phase, Dd, and the proportion of pores that drain at the first suction level or air entry value. Two simplified cases of the general model are also presented. The first simplified model (simplified case 1 [SC1]) is a special case of the GM in which all of the largest pores drain completely at the first suction level. The second model (simplified case 2 [SC2]) is a scale‐invariant model in which the proportion of drained pores for each suction level remains constant and is obtained by setting Dd equal to the mass fractal dimension, D of the porous medium. Fitting each model to numerically simulated drainage curves for random two‐dimensional prefractal porous media with known D values shows that the GM fitted the numerical data much better than either the SC1 or SC2 models, which were less flexible at high D values. Estimates of Dd for the GM and SC1 models approached D when D was less than the critical value for percolation, that is, Dc ∼1.716. Independent estimates of the probability of drainage indicate that the connectivity of water‐filled pores decreases as a result of the lower porosities associated with higher D values. A novel experimental protocol is suggested for testing these theoretical observations.
Cognitive complications moderate the speed‐accuracy tradeoff in data entry: a cognitive antidote to inhibition
Authors: Kole James A. , Healy Alice F. , Bourne Lyle E.
Published: October 2007

Three experiments explored a speed‐accuracy tradeoff reflecting decreasing response times (RTs) and increasing errors across trials in a data entry task. In Experiment 1, cognitive and motoric stressors were independently added to data entry, with the combination of stressors yielding the greatest decline in accuracy across blocks. Experiment 2 compared mental multiplication and simple data entry and manipulated the provision of feedback. Accuracy improved with both mental multiplication and feedback. Experiment 3 varied only the concluding keystroke; this extra requirement led to overall improvements in accuracy. In each experiment, RTs improved across trials. These results suggest that cognitive complications can serve as antidotes to inhibitory effects and can overcome the decline in accuracy due to continuous work on data entry. Copyright © 2007 John Wiley & Sons, Ltd.
Sickle cell bone disease: Response to vitamin D and calcium
Authors: Adewoye Adeboye H. , Chen Tai C. , Ma Qianli , McMahon Lillian , Mathieu Jeff , Malabanan Alan , Steinberg Martin H. , Holick Michael F.
Published: October 2007

Bone disease with osteoporosis and osteomalacia are common in sickle cell disease (SCD). Some patients have vitamin D deficiency and low bone mineral density (BMD). The role of vitamin D and calcium supplementation to restore bone health in SCD has not been well studied. In 14 adults with SCD, we measured 25(OH)D (25‐hydroxyvitamin D) and BMD at the femoral neck, lumbar spine, and distal third of the ulna plus radius, along with markers of bone resorption (CTx; C‐terminal component of pro‐collagen type I) and bone formation (osteocalcin) before and after 12 months of vitamin D2 and calcium carbonate treatment. Pretreatment, all patients were vitamin D deficient with a mean 25(OH)D level of 10.7 ± 4.7 ng/ml, had low BMD at the lumbar spine (L‐spine), 0.87 ± 0.11 g/cm2 (mean Z‐score of –2.6 3 ± 0.71 SD and T score of –2.31 ± 0.75 SD), femoral neck, 0.8 ± 0.18 g/cm2 (mean Z‐score –1.36 ± 0.84, T‐score –1.14 ± 0.75), and the distal radius and ulna, 0.6 ± 0.17 g/cm2 (mean Z‐score –1.18 ± 0.79, T‐score –1.01 ± 0.74) and had elevated CTx (0.87 ± 0.5 ng/ml) and osteocalcin levels (12.3 ± 3.7 ng/μl). After treatment, all patients corrected their 25(OH)D level (38.8 ± 13.9 ng/ml) (P < 0.001) with a 3.6% ± 3.9% increase in BMD at the L‐spine (P = 0.009), 4.6% ± 8.5% increase at the femoral neck (P = 0.05) and 6.5% ± 12.6% increase at the distal radius plus ulna (P = 0.09). CTx, osteocalcin, and PTH(i) levels were unchanged. Treatment of adult SCD with vitamin D and calcium can restore 25(OH)D levels to normal and improve BMD, but, markers of bone resorption remained unchanged. Screening for vitamin D deficiency and BMD in SCD patients seems warranted. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
5‐(N‐ethyl‐N‐isopropyl)‐amiloride enhances SMN2 exon 7 inclusion and protein expression in spinal muscular atrophy cells
Authors: Yuo Chung‐Yee , Lin Hui‐Hua , Chang Ya‐Sian , Yang Wen‐Kuang , Chang Jan‐Gowth
Published: October 2007

Objective

Spinal muscular atrophy (SMA) is a common inherited neuromuscular disorder caused by homozygous loss of function of the survival motor neuron 1 (SMN1) gene. All SMA patients carry at least one copy of a nearly identical SMN2 gene. However, a critical nucleotide change in SMN2 results in alternative splicing and exclusion of exon 7 in the majority of SMN2 messenger RNA (mRNA), thus producing a low level of functional SMN protein. Increasing SMN protein production by promoting SMN2 exon 7 inclusion could be a therapeutic approach for SMA. It has been shown that cellular pH microenvironment can modulate pre‐mRNA alternative splicing in vivo. In this study, we tested whether inhibitors of the Na+/H+ exchanger can modulate the exon 7 splicing of SMN2 mRNA

Methods

We treated SMA lymphoid cell lines with Na+/H+ exchanger inhibitors and then measured SMN2 exon 7 splicing by reverse transcriptase polymerase chain reaction and SMN protein production by Western blotting and immunofluorescence

Results

We found that treatment with an Na+/H+ exchanger inhibitor, 5‐(N‐ethyl‐N‐isopropyl)‐amiloride (EIPA), significantly enhances SMN2 exon 7 inclusion and SMN protein production in SMA cells. In addition, EIPA increases the number of nuclear gems in SMA cells. We further explored the underlying mechanism, and our results suggest that EIPA may promote SMN2 exon 7 inclusion through upregulation of the splicing factor SRp20 in the nucleus

Interpretation

Our finding that EIPA, an inhibitor of the Na+/H+ exchanger, can increase SMN protein expression in SMA cells provides a new direction for the development of drugs for SMA treatment. However, further translational studies are needed to determine whether this finding is applicable for SMA treatment or just a proof of cellular pH effect on SMN splicing. Ann Neurol 2007
Fullerene: vielseitige Bausteine für molekulare Maschinen
Authors: Mateo‐Alonso Aurelio , Guldi Dirk M. , Paolucci Francesco , Prato Maurizio
Published: October 2007

Molekulare Maschinen führen definierte Aufgaben aus, die in Verbindung mit molekularer Bewegung stehen. Dieser Kurzaufsatz illustriert, welche Einsatzmöglichkeiten den Fullerenen als vielseitigen Bausteinen in molekularen Maschinen offenstehen. Tatsächlich eignet sich C60 als außerordentlich nützlicher licht‐ und elektroaktiver Stopper (aufgrund seiner außergewöhnlichen Größe), als Sonde zur Erfassung molekularer Bewegungen (aufgrund seiner definierten physikochemischen Eigenschaften), und zum Auslösen solcher Bewegungen (durch einfache π‐π‐Wechselwirkungen). Derartige molekulare Bewegungen können beispielsweise durch Licht angetriebene Elektronentransferprozesse modulieren.
Fullerenes: Multitask Components in Molecular Machinery
Authors: Mateo‐Alonso Aurelio , Guldi Dirk M. , Paolucci Francesco , Prato Maurizio
Published: October 2007

Molecular machines are molecular‐scale devices that carry out predetermined tasks derived from molecular motion. This Minireview illustrates how fullerenes can be used as multitask building blocks in molecular machinery, providing new perspectives for fullerenes. Indeed, C60 can be applied as a photo‐ and electroactive stopper owing to its size, as a probe for molecular motion as a result of its well‐defined physicochemical properties, and to induce motion through π–π interactions. Such molecular motion can be employed to modulate light‐driven electron‐transfer events, extending the potential applications of molecular machines to the typical fields of application of fullerenes.
Minimisation of fuel energy wastage by improved heat exchanger network design—an industrial case study
Authors: Ashaibani Adel S. , Mujtaba Iqbal M.
Published: October 2007

Petroleum refineries fulfil their energy (process heat) requirement by direct fuel firing. In this regard, a heat exchanger network (HEN) is widely used to recover thermal energy that may be otherwise wasted. The HEN can significantly reduce the overall energy consumption in industrial processes. In many industrial processes such as oil refineries, crude oil needs to be heated to a required temperature. Here a study of a HEN problem of a crude oil distillation unit of an African Oil Refining Company (AORC) is carried out. In this unit the crude is required to enter the distillation column at 328 °C, while the crude inlet temperature at the furnace is only 220 °C. Therefore, a heater must supply heat to raise the temperature by a third of the target temperature. In this work pinch technology is used in the existing HEN in order to obtain a desirable energy saving and to identify the required additional modification. With the addition of only one heat exchanger and re‐construction of the HEN, significant utility savings are achieved. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
Furan–thiophene copolymers: Electrosynthesis and electrochemical behavior
Authors: Alakhras Fadi , Holze Rudolf
Published: October 2007

The electrochemical copolymerization of furan and thiophene was performed at a constant electrode potential in a binary solvent system consisting of boron trifluoride/ethyl ether and an additional amount of ethyl ether (molar ratio = 1 : 2). The obtained homopolymers and copolymers were characterized with cyclic voltammetry and infrared spectroscopy. The influence of the applied electropolymerization potential and the monomer feed ratio of furan and thiophene on the copolymers was investigated. The furan–thiophene copolymers showed good stability of the redox activity in an acetonitrile‐based electrolyte solution. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Hollow porous poly(lactic acid) microspheres
Authors: Wang Hualin , Zuo Jingping , Yu Shaoming , Chen Jihai , Song Qiusheng , Shi Tiejun
Published: October 2007

On the basis of the water solubility of poly(N‐vinyl‐2‐pyrrolidinone), hollow porous poly(lactic acid) microspheres (HPPLAs) were prepared by a water‐in‐oil‐in‐water multiple‐emulsion solvent evaporation method. The influence of the concentration of the stabilizer Span80 in the oil phase on the morphology was investigated. It was found that when the content of Span80 solutions was 3.5 wt %, most HPPLAs were about 2 μm in diameter. Field scanning electron microscopy results show that the HPPLAs were porous and hollow. The structure and crystal form of the HPPLAs were characterized by Fourier transform infrared spectroscopy and X‐ray diffraction analysis. Using these HPPLAs as degradable templates, we successfully synthesized Litchi‐like polystyrene (PS) microspheres about 2 μm in diameter by the emulsion method. When used as drug carriers, these HPPLAs would be convenient in which to embed drugs, whereas the Litchi‐like PS microspheres may have potential as new materials for polymer modification. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Synthesis and characterization of novel chain‐extended bismaleimides containing fluorenyl cardo structure
Authors: Hu Zhiqiang , Li Shanjun , Zhang Chunhua
Published: October 2007

Novel fluorenyl cardo chain‐extended bismaleimides (FCCEBMIs) were synthesized by reacting maleic anhydride with fluorenyl cardo diamine and different dianhydrides. FCCEBMIs were characterized by FT‐IR spectra (FT‐IR), 1H NMR, and elemental analysis. All FCCEBMI monomers were readily soluble in a variety of organic solvents, such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethyl acetamide, chloroform (CHCl3), methylene chloride (CH2Cl2), dimethyl sulfoxide, and tetrahydrofuran when compared with 9,9‐bis(4‐maleimidophenyl) fluorene. Curing process was investigated by differential scanning calorimetry. Thermal properties of the cured FCCEBMIs were characterized by thermogravimetry analysis, the cured products are stable up to 430°C. The results show that the FCCEBMIs with imide structure improve significantly the solubility of bismaleimide (BMI) in organic solvents without sacrificing thermal properties of cured BMIs. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Cellulosic biomass feedstocks and logistics for ethanol production
Authors: Hess J. Richard , Wright Christopher T. , Kenney Kevin L.
Published: October 2007

The economic competitiveness of cellulosic ethanol production is highly dependent on feedstock cost, which constitutes 35–50% of the total ethanol production cost, depending on various geographical factors and the types of systems used for harvesting, collecting, preprocessing, transporting, and handling the material. Consequently, as the deployment of cellulosic ethanol biorefineries approaches, feedstock cost and availability are the driving factors that influence pioneer biorefinery locations and will largely control the rate at which this industry grows. Initial scenarios were postulated to develop a pioneer dry feedstock supply system design case as a demonstration of the current state of technology. Based on this pioneer design, advanced scenarios were developed to determine key cost barriers, needed supply system improvements, and technology advancements to achieve government and private sector cost targets. Analysis of the pioneer supply system resulted in a delivered feedstock cost to the throat of the pretreatment reactor of $37.00 per dry tonne (2002 $). Pioneer supply systems will start by using current infrastructure and technologies and be individually designed for biorefineries using specific feedstock types and varieties based on local geographic conditions. As the industry develops and cost barriers are addressed, the supply systems will incorporate advanced technologies that will eliminate downstream diversity and provide a uniform, tailored feedstock for multiple biorefineries located in different regions. Published in 2007 by John Wiley & Sons, Ltd.
ROC Volumes – Should They Be Used?
Authors: McClish Donna K.
Published: October 2007

Invited comment on Alonzo, T.A. and Nakas, C.T. (2007). Comparison of ROC umbrella volumes with an application to the assessment of lung cancer diagnostic markers. Biometrical Journal 49, 654–664.

Issues remain as to the appropriateness of volumes as summary measures of accuracy when distinguishing between multiple disease classes and when comparing accuracy of tests. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Umbrella Volume: Is it Useful in Applications?
Authors: Martus Peter
Published: October 2007

Invited comment on Alonzo, T. A. and Nakas, C. T. (2007). Comparison of ROC umbrella volumes with an application to the assessment of lung cancer diagnostic markers. Biometrical Journal 49, 654–664.

The umbrella volume, proposed as a parameter for diagnostic validity in a specific three group situation might be difficult to interpret in clinical applications. It should be used very cautiously. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Continuous Laboratory Gold Solvent Extraction from Cyanide Solutions using LIX 79 Reagent
Authors: Aguayo S. , Valenzuela J. L. , Parga J. R. , Lewis R. G. , Cruz M.
Published: October 2007

Continuous laboratory solvent extraction of gold from cyanide solutions has been investigated by using LIX 79 guanidine‐based extractant. Different variables that affected the extraction included aqueous pH, extractant concentration and modifier concentration. Extraction isotherms of the aurocyanide complex with respect to the other cyanoanions were compared, and the following order of selectivity was observed: Au > Ag > Cu > Zn > Fe. According to the pH isotherms, aurocyanide can be extracted in alkaline media, and a better separation with respect to other cyano anions was obtained in the pH range 10.5–11.2. From the McCabe‐Thiele diagrams, better recovery was observed when using LIX 79 and tridecanol at 10 vol.‐%. Stripping gold from the loaded organic was carried out at pH > 12 by using NaOH and NaCN solutions. The pilot plant tests indicate that a two‐stage extraction followed by one strip step are more than adequate to obtain an overall process efficiency of 92 %. However, for those cases where copper is present significantly, a copper wash stage is recommended before gold stripping. In this case, stripping of copper is accomplished at a pH 10.8, whereas the gold stripping was done at a pH of 12.0.
Double restricted Co‐Inertia Analysis
Authors: Amenta Pietro
Published: October 2007

In this paper, an extension of the Co‐Inertia Analysis 1 is proposed. This extension is based on an objective function which takes directly into account the external information, as linear restrictions, about parameters of both sets of variables, by rewriting the Co‐Inertia Analysis objective function according to the principle of Restricted Eigenvalue Problem 2. A restricted extension of Wold's two‐block ‘Mode A’ Partial Least Squares 3 is also proposed. Copyright © 2007 John Wiley & Sons, Ltd.
New and Efficient Arrays for Photoinduced Charge Separation Based on Perylene Bisimide and Corroles
Authors: Flamigni Lucia , Ventura Barbara , Tasior Mariusz , Becherer Thomas , Langhals Heinz , Gryko Daniel T.
Published: October 2007

The bichromophoric systemsC2‐PI,C3‐PI, andC3‐PPIconsisiting of corrole and perylene bisimide units and representing one of the rare cases of elaborate structures based on corrole, have been synthesized. CorrolesC2andC3are, respectively,meso‐substituted corroles with 2,6‐dichlorophenyl and pentafluorophenyl substituents at the 5 and 15 positions. The three dyads were prepared by divergent strategy with the corrole‐forming reaction as the last step of the sequence.C2‐PIandC3‐PIdiffer in the nature of the corroles, whereasC3‐PIdiffers fromC3‐PPIin the presence of a further phenyl unit in the linker between photoactive units. The dyads display spectroscopic properties which are the superposition of the component spectra, indicating a very weak electronic coupling. Excitation of the corrole unit leads to charge separation with a rate which decreases from 2.4×1010, to 5.0×109, and to 4.9×107 s−1forC2‐PI,C3‐PI, andC3‐PPI, respectively, where the reaction is characterized by a ΔG°>0. Excitation of the perylene bisimide unit is followed by competing reactions of: 1) energy transfer to the corrole unit, which subsequently deactivates to the charge‐separated state and; 2) electron transfer to directly form the charge‐separated state. The ratio of electron‐to‐energy‐transfer rates is 9:1 and 1:1 forC3‐PIandC3‐PPI, respectively. The yield of charge separation is essentially 100 % forC2‐PIandC3‐PI, and approximately 50 % (excitation of peryleneimide) or 15 % (excitation of the corrole) forC3‐PPI.The lifetime of the charge‐separated state, observed for the first time in corrole‐based structures, is 540 ps forC2‐PI, 2.5 ns forC3‐PI, and 24 ns forC3‐PPI, respectively. This is in agreement with an inverted behavior, according to Marcus theory.
Gamma knife radiosurgery for central neurocytoma
Authors: Kim Chae‐Yong , Paek Sun Ha , Jeong Sang Soon , Chung Hyun‐Tai , Han Jung Ho , Park Chul‐Kee , Jung Hee‐Won , Kim Dong Gyu
Published: October 2007

BACKGROUND.

Little is known about long‐term results of gamma knife (GK) stereotactic radiosurgery (SRS) as a primary or a secondary postoperative therapy for central neurocytomas (CNs). The authors retrospectively reviewed long‐term outcomes of 13 patients with CN treated with GK SRS.

METHODS.

Thirteen patients were treated with GK SRS as a primary (6 patients) or a secondary postoperative therapy (7 patients). Follow‐up clinical status and brain magnetic resonance imaging (MRI) were thoroughly analyzed. The functional status of patients was assessed with the Karnofsky Performance Scale during follow‐up.

RESULTS.

The median follow‐up period for clinical status and imaging studies was 61 months (range, 6 months to 96 months). Tumors decreased in 5 patients who received GK SRS as a primary treatment. However, the tumor recurred in 2 patients treated with a secondary GK SRS after surgery from the residual tumor bed that was not covered by the GK SRS. Parenchymal changes and secondary malignancies were not found in follow‐up MRIs of all 13 patients. The Karnofsky Performance Scale score of all patients, except for 1 patient who suffered from an unrelated anteriorly communicating arterial aneurysmal rupture, did not change after GK SRS.

CONCLUSIONS.

GK SRS may be useful as a primary or a secondary postoperative therapy for the treatment of CN. However, more attention should be paid to residual or recurrent CN during treatment, and regular long‐term follow‐up MRI should be mandatory to validate the procedure. Cancer 2007 © 2007 American Cancer Society.
Ectopia of meningeal fibroblasts and reactive gliosis in the cerebral cortex of the mouse model of muscle‐eye‐brain disease
Authors: Yang Yuan , Zhang Peng , Xiong Yufang , Li Xiaofeng , Qi Yue , Hu Huaiyu
Published: October 2007

Congenital muscular dystrophies with brain malformations, such as muscle‐eye‐brain disease, exhibit neural ectopias caused by overmigration of neurons. Such overmigration is evident in protein O‐mannose β‐1,2‐N‐acetylglucosaminyltransferase (POMGnT1) knockout mouse, a model of muscle‐eye‐brain disease, caused by breaches in the pial basement membrane. We hypothesize that breaches in pial basement membrane disrupt the neural‐meningeal boundary, resulting in ectopia of meningeal fibroblasts in the cerebral cortex and reactive gliosis. To test this hypothesis, the cerebral cortices of developing and adult POMGnT1 knockout mice were analyzed by immunostaining with cell‐specific markers and by electron microscopy. The upper half of the cerebral cortex in the knockout mouse contained increased numbers of fibroblasts closely associated with capillaries. During development of the cerebral cortex in the knockout mice, breaches in pial basement membrane allowed emigration of overmigrated neurons into the developing pia‐arachnoid, scattering its mesenchymal cells throughout the diffuse cell zone and resulting in ectopia of mesenchyme‐derived fibroblasts in the upper half of the cortex. Glial fibrillary acidic protein (GFAP) immunostaining revealed that the upper half of the cerebral cortex in the knockout also contained increased numbers of cells with morphologies typical of reactive astrocytes compared with the wild type. Moreover, most of the GFAP‐positive reactive astrocytes were in close contact with ectopic fibroblasts, suggesting that they were induced by the fibroblasts. Collectively, the data support the hypothesis that the cerebral cortex of POMGnT1 knockout mice is characterized by migration defects leading to disruption of the pia‐arachnoid, ectopia of fibroblasts in the cortex, and reactive gliosis. J. Comp. Neurol. 505:459–477, 2007. © 2007 Wiley‐Liss, Inc.
Otolith endorgan input to the Mauthner neuron in the goldfish
Authors: Szabo Theresa M. , McCormick Catherine A. , Faber Donald S.
Published: October 2007

The Mauthner (M‐) cell of the goldfish, Carassius auratus, triggers the rapid escape response of the fish in response to various stimuli, including visual and auditory. The large size and accessibility of the M‐cell make it an ideal model system for the study of synaptic transmission, membrane properties, and sensory‐motor gating. Although physiological recordings have suggested that afferents from all three of the inner ear endorgans (the saccule, lagena, and utricle) synapse directly on the ipsilateral M‐cell, the specific contacts and anatomical distributions of these inputs along the M‐cell lateral dendrite remain unknown. We traced specific branches of the auditory (VIIIth) nerve from the three otolith organs of the fish inner ear to the M‐cell. The goldfish sacculus gives rise to the vast majority of inputs that contact a large portion of the M‐cell lateral dendrite, and these inputs vary greatly in size. In contrast to the ubiquitous distribution of saccular inputs, those from the lagena are segregated to distal regions of the M‐cell and synapse on the distal dorsal branch of the lateral dendrite. Similarly, inputs from the utricle are also segregated to distal regions, synapsing on the ventral branch of the lateral dendrite. These results demonstrate that nerves from all three endorgans contact the M‐cell, with input‐specific segregation of synapses along the M‐cell lateral dendrite. J. Comp. Neurol. 505:511–525, 2007. © 2007 Wiley‐Liss, Inc.
Distinct populations of presympathetic‐premotor neurons express orexin or melanin‐concentrating hormone in the rat lateral hypothalamus
Authors: Kerman Ilan A. , Bernard René , Rosenthal Devin , Beals James , Akil Huda , Watson Stanley J.
Published: October 2007

Orexin and melanin‐concentrating hormone (MCH) have been implicated in mediating a variety of different behaviors. These include sleep and wakefulness, locomotion, ingestive behaviors, and fight‐or‐flight response, as well as anxiety‐ and panic‐like behaviors in rodents. Despite such diversity, all these processes require coordinated recruitment of the autonomic and somatomotor efferents. We have previously mapped the locations of presympathetic‐premotor neurons (PSPMNs) in the rat brain. These putative dual‐function neurons send trans‐synaptic projections to somatomotor and sympathetic targets and likely participate in somatomotor‐sympathetic integration. A significant portion of these neurons is found within the dorsomedial (DMH) and lateral hypothalamus (LH), areas of the brain that contain MCH‐ and orexin‐ synthesizing neurons in the central nervous system. Thus, we hypothesized that hypothalamic PSPMNs utilize MCH or orexin as their neurotransmitter. To test this hypothesis, we identified PSPMNs by using recombinant strains of the pseudorabies virus (PRV) for trans‐synaptic tract tracing. PRV‐152, a strain that expresses enhanced green fluorescent protein, was injected into sympathectomized gastrocnemius muscle, whereas PRV‐BaBlu, which expresses β‐galactosidase, was injected into the adrenal gland in the same animals. By using immunofluorescent methods, we determined whether co‐infected neurons express MCH or orexin. Our findings demonstrate that PSPMNs synthesizing either MCH or orexin are present within LH, where they form two separate populations. PSPMNs located around the fornix express orexin, whereas those located around the cerebral peduncle are more likely to express MCH. These two clusters of PSPMNs within LH likely play distinct functional roles in autonomic homeostasis and stress coping mechanisms. J. Comp. Neurol. 505:586–601, 2007. © 2007 Wiley‐Liss, Inc.
Dendritic spread and functional coverage of starburst amacrine cells
Authors: Keeley Patrick W. , Whitney Irene E. , Raven Mary A. , Reese Benjamin E.
Published: October 2007

The network of starburst amacrine cells plays a fundamental role in the neural circuitry underlying directional selectivity within the retina. Individual sectors of the starburst dendritic field are directionally selective by virtue of a mutually inhibitory relationship between starburst amacrine cells with overlapping dendrites. These features of the starburst amacrine cell network suggest that starburst cells regulate their dendritic overlap to ensure a uniform coverage of the retinal surface. The present study has compared the dendritic morphology of starburst amacrine cells in two different strains of mice that differ in starburst amacrine cell number. The A/J (A) strain contains about one‐quarter fewer starburst amacrine cells than does the C57BL/6J (B6) strain, although the mosaics of starburst amacrine cells in both strains are comparably patterned. Dendritic field size, however, does not compensate for the difference in density, the A strain having a slightly smaller dendritic field relative to the B6 strain, yielding a significantly larger dendritic coverage factor for individual cells in the B6 strain. The area of the distal (output) annulus of the dendritic field occupies a comparable proportion of the overall field area in the two strains, but overlapping annuli establish a finer meshwork of co‐fasciculating processes in the B6 strain. These results would suggest that the architecture of the dendritic network, rather than the overall size of the dendritic field, is dependent on the density of starburst amacrine cells. J. Comp. Neurol. 505:539–546, 2007. © 2007 Wiley‐Liss, Inc.
Embedding Magnetic Nanoparticles into Polysaccharide‐Based Hydrogels for Magnetically Assisted Bioseparation
Authors: Liang Yuan‐Yuan , Zhang Li‐Ming , Jiang Wei , Li Wei
Published: October 2007

Based on the preparation of biocompatible polysaccharide‐based hydrogels with stimuli‐responsive properties by the copolymerization of maleilated carboxymethyl chitosan with N‐isopropylacrylamide, novel magnetic hybrid hydrogels were fabricated by the in situ embedding of magnetic iron oxide nanoparticles into the porous hydrogel networks. Scanning electron microscopy (SEM) and thermogravimetric (TG) analyses showed that the size, morphology, and content of the iron oxide nanoparticles formed could be modulated by controlling the amount of maleilated carboxymethyl chitosan. As confirmed by X‐ray diffractometry (XRD), equilibrium swelling ratio, and differential scanning calorimetry (DSC) measurements, the embedding process did not induce a phase change of the magnetic iron oxide nanoparticles, and the resultant hybrid hydrogels could retain the pH‐ and temperature‐responsive characteristics of their hydrogel precursors. By investigating the partition coefficients of bovine serum albumin as a model protein, this magnetic hydrogel material was found to hold a potential application in magnetically assisted bioseparation.
Icosahedral and Ring‐Shaped Allotropes of Arsenic
Authors: Karttunen Antti J. , Linnolahti Mikko , Pakkanen Tapani A.
Published: October 2007

We predict the existence of two novel families of arsenic nanostructures: icosahedral cages and ring‐shaped chains. Quantum chemical calculations on the cages, rings, and the experimentally known allotropes of arsenic suggest the nanostructures to be thermodynamically stable. The icosahedral cages are modifications of the gray allotrope of arsenic, while the ring‐shaped chains are structurally related to the red allotrope of phosphorus. Comparisons between the analogous allotropes of arsenic and phosphorus show distinct differences. While phosphorus favors the ring‐shaped chains over the icosahedral cages, large cages become favorable for arsenic. From the thermodynamical point of view, experimental preparation of the proposed families of arsenic nanostructures is expected to be viable.
Structures and Electronic Properties of C56Cl8 and C56Cl10 Fullerene Compounds
Authors: Chen De‐Li , Tian Wei Quan , Feng Ji‐Kang , Sun Chia‐Chung
Published: October 2007

Stimulated by the recent observation of the first C56Cl10 chlorofullerene (Science, 2004, 304, 699), we performed a systematic density functional study of the structures and properties of C56Cl10 and related compounds. The fullerene derivatives C56Cl8 and C56Cl10 based on the parent fullerene C56(C2v:011), rather than those from the most stable C56 isomer with D2 symmetry, are predicted to possess the lowest energies, and they are highly aromatic. Further investigations show that the heats of formation of the C56Cl8 and C56Cl10 fullerene derivatives are highly exothermic, that is, −48.59 and −48.89 kcal mol−1 per Cl2 (approaching that of C50Cl10), suggesting that adding eight (or ten) Cl atoms releases much of the strain of pure C56(C2v:011) fullerene and leads to highly stable derivatives. In addition, C56Cl8 and C56Cl10 possess large vertical electron affinities, especially for C56Cl8 with value of 3.20 eV, which is even larger than that (3.04 eV) of C50Cl10, indicating that they are potential good electron acceptors with possible photonic/photovoltaic applications. Finally, the 13C NMR chemical shifts and infrared spectra of C56Cl8 and C56Cl10 are simulated to facilitate future experimental identification.
Insights into the Molecular Structure and Reactivity of α,ω‐Dialkoxy‐Substituted Ethyne and Butadiyne
Authors: Gleiter Rolf , Werz Daniel B. , Rominger Frank , Zhutov Evgeny , Zefirov Nikolay S. , Proskurnina Marina V.
Published: October 2007

The molecular structure derived by X‐ray crystallography and the He(I) photoelectron spectrum of bis(tert‐butoxy)butadiyne (4a) are reported. Bis(tert‐butoxy)ethyne (3a) and 4a were treated with highly electrophilic [η2‐bis(tert‐butylsulfonyl)ethyne](carbonyl)(η5‐cyclopentadienyl)cobalt (10). In both cases a CpCo‐stabilized cyclobutadiene ring resulted substituted by two tert‐butylsulfonyl groups and either two tert‐butoxy groups (→11) or one tert‐butoxy group and one tert‐butoxyethynyl group (→12). The structural data of 11 and of (η4‐tetrakis(tert‐butoxy)cyclopentadienone)(cyclopentadienyl)cobalt (15) are reported and compared with related species. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Rearrangement of S‐(2‐Aminoethyl) Thiophosphates to N‐(2‐Mercaptoethyl)phosphoramidates
Authors: Chen Menglin , Maetzke Alice , Knak Jensen Svend J. , Gothelf Kurt V.
Published: October 2007

A novel rearrangement of S‐(2‐aminoethyl) thiophosphates to N‐(2‐mercaptoethyl)phosphoramidates was discovered and developed. The reaction proceeds smoothly at room temperature under basic conditions and the resulting thiol could subsequently be alkylated. The reaction mechanism is investigated by electron structure calculations using density functional theory at the B3LYP/6‐31G(d) and B3LYP/6‐311+G(d,p) levels. The calculations indicate that the reaction proceeds in a two step process when two explicit solvent molecules are included. In the presence of water the rearrangement reaction proceeds in competition with hydrolysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Market microstructure effects on volatility at the TAIFEX
Authors: Webb Robert I. , Muthuswamy Jayaram , Segara Reuben
Published: October 2007

This study examines whether changes in the frequency of market clearing or changes in trading hours on competing exchanges that use different auction systems affect the volatility of futures prices. In particular, this study exploits a natural experiment in the frequency of market clearing of stock index futures contracts traded on the Taiwan Futures Exchange (TAIFEX) to assess whether successive increases in the frequency of market clearing are associated with changes in the volatility of futures prices. The impact of changes in the trading hours on the TAIFEX and on the competing Singapore Exchange (SGX) where a similar Taiwanese stock index futures contract trades under a continuous auction market regime is also examined. The evidence for the impact of an increase in the frequency of market clearing on volatility is mixed. However, the introduction of simultaneous opening times for the TAIFEX (which batches orders at the open) and the SGX (which does not) is associated with a significant reduction in the volatility in SGX Taiwanese stock index futures prices. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:1219–1243, 2007