bluuebunny/crossref_metadata_2025 huggingface dataset:
Suppressor of Fused Is Required to Maintain the Multipotency of Neural Progenitor Cells in the Retina
Authors: Cwinn Matt A. , Mazerolle Chantal , McNeill Brian , Ringuette Randy , Thurig Sherry , Hui Chi-chung , Wallace Valerie A.
Published: March 2011

The morphogen sonic hedgehog (Shh) plays a crucial role in development of the CNS, including the neural retina.Suppressor of fused(Sufu) has been recently identified as a critical regulator of Hh signaling in mammals. However, the precise roles thatSufuplays in the regulation of proliferation and cell-fate decisions in neural progenitors is unknown. Here, we have addressed these questions by conditionally deletingSufuin mouse multipotent retinal progenitor cells (RPCs).Sufudeletion in RPCs results in transient increases in Hh activity and proliferation followed by developmentally premature cell-cycle exit. Importantly, we demonstrate a novel role forSufuin the maintenance of multipotency in RPCs.Sufu-null RPCs downregulate transcription factors required to specify or maintain RPC identity (Rax,Vsx2) and multipotency (Pax6) but continue to express the neural progenitor markerSox2. These cells fail to express retinal lineage-specific transcription factors, such asMath5, and adopt an amacrine or horizontal cell fate at the expense of all other classes of retinal neurons. Genetic elimination ofGli2inSufu-null RPCs attenuates Hh pathway activity and restores multipotency in neural progenitors. These data provide novel evidence thatSufu-mediated antagonism of Hh/Gli2signaling is required to maintain RPC multipotency and identity.
Thyroid Hormone Controls Cone Opsin Expression in the Retina of Adult Rodents
Authors: Glaschke Anika , Weiland Jessica , Del Turco Domenico , Steiner Marianne , Peichl Leo , Glösmann Martin
Published: March 2011

Mammalian retinas display an astonishing diversity in the spatial arrangement of their spectral cone photoreceptors, probably in adaptation to different visual environments. Opsin expression patterns like the dorsoventral gradients of short-wave-sensitive (S) and middle- to long-wave-sensitive (M) cone opsin found in many species are established early in development and thought to be stable thereafter throughout life. In mouse early development, thyroid hormone (TH), through its receptor TRβ2, is an important regulator of cone spectral identity. However, the role of TH in the maintenance of the mature cone photoreceptor pattern is unclear. We here show that TH also controls adult cone opsin expression. Methimazole-induced suppression of serum TH in adult mice and rats yielded no changes in cone numbers but reversibly altered cone patterns by activating the expression of S-cone opsin and repressing the expression of M-cone opsin. Furthermore, treatment of athyroid Pax8−/−mice with TH restored a wild-type pattern of cone opsin expression that reverted back to the mutant S-opsin-dominated pattern after termination of treatment. No evidence for cone death or the generation of new cones from retinal progenitors was found in retinas that shifted opsin expression patterns. Together, this suggests that opsin expression in terminally differentiated mammalian cones remains subject to control by TH, a finding that is in contradiction to previous work and challenges the current view that opsin identity in mature mammalian cones is fixed by permanent gene silencing.
Inputs Underlying the ON–OFF Light Responses of Type 2 Wide-Field Amacrine Cells in TH::GFP Mice
Authors: Knop Gabriel C. , Feigenspan Andreas , Weiler Reto , Dedek Karin
Published: March 2011

In the mammalian retina, two types of catecholaminergic amacrine cells have been described. Although dopaminergic type 1 cells are well characterized, the physiology of type 2 cells is, so far, unknown. To target type 2 cells specifically, we used a transgenic mouse line that expresses green fluorescent protein under the control of the tyrosine hydroxylase promoter. Type 2 cells are GABAergic and have an extensive dendritic arbor, which stratifies in the middle of the inner plexiform layer. Our data suggest that type 2 cells comprise two subpopulations with identical physiological properties: one has its somata located in the inner nuclear layer and the other in the ganglion cell layer. Immunostaining with bipolar cell markers suggested that type 2 cells receive excitatory inputs from type 3 OFF and type 5 ON bipolar cells. Consistently, patch-clamp recordings showed that type 2 cells are ON–OFF amacrine cells. Blocking excitatory inputs revealed that different rod and cone pathways are active under scotopic and mesopic light conditions. Blockade of inhibitory inputs led to membrane potential oscillations in type 2 cells, suggesting that GABAergic and glycinergic amacrine cells strongly influence type 2 cell signaling. Among the glycinergic amacrine cells, we identified the VGluT3-immunoreactive amacrine cell as a likely candidate. Collectively, light responses of type 2 cells were remarkably uniform over a wide range of light intensities. These properties point toward a general function of type 2 cells that is maintained under scotopic and mesopic conditions.
A Neurally Efficient Implementation of Sensory Population Decoding
Authors: Chaisanguanthum Kris S. , Lisberger Stephen G.
Published: March 2011

A sensory stimulus evokes activity in many neurons, creating a population response that must be “decoded” by the brain to estimate the parameters of that stimulus. Most decoding models have suggested complex neural circuits that compute optimal estimates of sensory parameters on the basis of responses in many sensory neurons. We propose a slightly suboptimal but practically simpler decoder. Decoding neurons integrate their inputs across 100 ms, incoming spikes are weighted by the preferred stimulus of the neuron of origin, and a local, cellular nonlinearity approximates divisive normalization without dividing explicitly. The suboptimal decoder includes two simplifying approximations. It uses estimates of firing rate across the population rather than computing the total population response, and it implements divisive normalization with local cellular mechanisms of single neurons rather than more complicated neural circuit mechanisms. When applied to the practical problem of estimating target speed from a realistic simulation of the population response in extrastriate visual area MT, the suboptimal decoder has almost the same accuracy and precision as traditional decoding models. It succeeds in predicting the precision and imprecision of motor behavior using a suboptimal decoding computation because it adds only a small amount of imprecision to the code for target speed in MT, which is itself imprecise.
Dezentrale, deadlockfreie Steuerung eines Stetigförderers
Authors: Schönung Frank , Mayer Stephan , Berbig Dominik
Published: March 2011

Veränderte Randbedingungen für die innerbetriebliche Logistik erfordern heute flexible, rekonfigurierbare Materialflusssysteme mit kurzen Inbetriebnahmezeiten. Bisherige automatisierte Intralogistiksysteme erfüllen diese Anforderungen nur zum Teil. Dieser Beitrag stellt einen neuen Lösungsansatz eines Plug & Work-fähigen Stetigförderers vor, der den Anforderungen gerecht werden soll. Basis des Systems sind dezentrale Steuerungsalgorithmen, die ohne Unterstützung einer zentralen Instanz die Topologieerkennung, das Routing von Fördereinheiten sowie die Verhinderung von Deadlocksituationen bewältigen.
Engineering von modularen Förderanlagen im Internet der Dinge
Authors: ten Hompel Michael , Nettsträter Andreas , Feldhorst Sascha , Schier Arkadius
Published: March 2011

Dieser Artikel gibt einen Überblick über Engineeringmethoden für modulare Förderanlagen nach dem Grundgedanken des Internet der Dinge. Durch strikte Modularisierung der mechanischen Fördermittel und durch Verteilung der Steuerungsintelligenz werden anpassungsfähige und skalierbare Materialflusssysteme bereits heute möglich. Neben der Beschreibung des Konzepts werden die Vorteile von modularen Systemen diskutiert. Den Kern des Artikels bildet die Beschreibung neuer Ansätze für das Engineering.
Konzertierte Gegnerbekämpfung im Achsenbündnis. Die Polizei im Dritten Reich und im faschistischen Italien 1933 bis 1943
Authors: Bernhard Patrick
Published: March 2011

Vorspann

Die „Achse“ erschöpfte sich nicht im Polittourismus der Staats- und Parteiführungen. Sie war ein hybrides Großexperiment der Völkerverständigung über Expansion und Krieg und erfasste schließlich alle Ebenen von Staat und Gesellschaft in Italien und im Deutschen Reich. Die Kooperation der Polizei war besonders eng – und folgenreich für Regimegegner und rassisch Verfolgte. Der Italienexperte Patrick Bernhard analysiert diese Transfer- und Radikalisierungsprozesse auf der Basis neuer Quellen und knüpft weitreichende Thesen an seine Befunde: Die Geschichte des Dritten Reiches müsse stärker kontextualisiert und mit der Geschichte des Faschismus verzahnt werden, weil sich nur so der historische Ort des NS-Regimes in der Krisen- und Kriegsgeschichte der ersten Hälfte des 20. Jahrhunderts exakt bestimmen lasse.
Ungeschminkte Wahrheiten. Ein vertrauliches Gespräch von Gerhard Schürer, Chefplaner der DDR, mit der Stasi über die Wirtschaftspolitik der SED im April 1978
Authors: Malycha Andreas
Published: March 2011

Vorspann

Alle wussten es – das Politbüro ebenso wie die Planungschefs, die Staatssicherheit und der mächtige Generalsekretär Erich Honecker: Die DDR hing schon in den siebziger Jahren am westlichen Tropf und fand keinen Ausweg aus der Schuldenfalle. Vorschläge, etwas daran zu ändern, gab es genug, wie Andreas Malycha vom Institut für Zeitgeschichte zeigen kann. Sie scheiterten aber am Veto von Honecker, der nicht bereit war, sein kostspieliges politisches Credo, die Einheit von Wirtschafts- und Sozialpolitik, aufzugeben. War Honecker blind geworden oder wusste er genau, dass es eine sparsame Alternative nicht mehr gab?
Periodically Ordered Mesoporous Co3O4/Heteropoly Acid Composite Frameworks for Catalytic Applications
Authors: Armatas Gerasimos S. , Tamiolakis Ioannis , Petrakis Dimitris E.
Published: March 2011

Mesoporous cobalt oxide-tungstophosphoric acid composite frameworks have been synthesized by structure replication from cubic mesoporous KIT-6 silica. The products possess a regular structure with uniform wall thickness (~7 nm) and large internal BET surface area (~87-141 m2/g). The pore walls of these materials consist of nanocrystalline Co3O4 and 12-tungstophosphoric acid (HPW) components with different HPW content, i.e. 6, 15 and 36 wt. %. Total X-ray scattering analysis and UV/vis spectroscopy confirmed the Keggin structure of HPW into the mesoporous frameworks. Preliminary catalytic experiments found that Co3O4-HPW composites exhibited a remarkable activity in the direct decomposition of nitrous oxide into N2 and O2.
Mechanically Biased Self-Assembly of Quantum Dots by Nanoindentation
Authors: Taylor Curtis R. , Malshe Ajay , Stach Eric , Marega Euclydes , Salamo Gregory
Published: April 2011

Nanoindentations were created in the GaAs(100) surface to act as strain centers to bias the nucleation of self-assembled InAs quantum dots providing for patterned growth. Indents were generated using loads below 450 μN with a sharp cube corner indenter. Growth of InAs quantum dots on indent patterns is performed using molecular beam epitaxy (MBE). The effect of indent spacing and size on the patterned growth is investigated. The structural analysis of the quantum dots including spatial ordering, size, and shape are characterized by ex-situ atomic force microscopy (AFM). Results reveal that the indent patterns clearly bias nucleation with dot structures selectively growing on top of each indent. It is speculated that the biased nucleation is due to a combination of favorable surface strain and multi-atomic step formation at the indent sites, which leads to increased adatom diffusion on the patterned area.
Anomalous Selective Tungsten- Growth by -Chemical- Vapor -Deposition
Authors: Mei Yu-Jane , Chang Ting-Chang , Sheu Jeng-Dong , Yeh Wen-Kuan , Pan Fu-Ming , Chang Chun-Yen
Published: April 2011

Selective tungsten chemical vapor deposition (W-CVD) is one of the most attractive technique for filling deep submicron contact hole and via hole for the ULSI application. In this work, we firstly find out the anomalous selective W growth for the contact hole. The tungsten only nucleates from the side ring of the contact hole bottom. Several predeposition treatments prior to W growth can improve this anomalous feature and excellently selective W growth can be achieved. Auger electron spectroscopy (AES) is utilized to investigate the interface of Si/W. A model has been proposed to explain this anomalous selective tungsten growth.
Atomistic Aspects of Crack Propagation Along High Angle Grain Boundaries
Authors: Farkas Diana
Published: April 2011

We present atomistic simulations of the crack tip configuration near a high angle Σ= 5 [001](210) symmetrical tilt grain boundary in NiAl. The simulations were carried out using molecular statics and embedded atom (EAM) potentials. The cracks are stabilized near a Griffith condition involving the cohesive energy of the grain boundary. The atomistic configurations of the tip region are different in the presence of the high angle grain boundary than in the bulk. Three different configurations of the grain boundary were studied corresponding to different local compositions. It was found that in ordered NiAl, cracks along symmetrical tilt boundaries show a more brittle behavior for Al rich boundaries than for Ni-rich boundaries. Lattice trapping effects in grain boundary fracture were found to be more significant than in the bulk.
The Effects of Implanted Nitrogen on Diffusion of Boron and Evolution of Extended Defects
Authors: Park Heemyong , Ilderem Vida , Jasper Craig , Kaneshiro Mike , Christiansens Jim , Jones Kevin S.
Published: April 2011

We studied effects of nitrogen on reduction of boron diffusion in BF2-implanted source/drain regions of a p-channel MOSFET. Evolution of extended defects induced by nitrogen implantation in silicon and its dependence on implant energy were investigated. Characterization with TEM and SIMS led to validation of models of nitrogen as interstitial traps and strain-induced gettering. Electrical measurement of the PMOS threshold voltage shows a consistent trend of the nitrogen effects on boron redistribution in the S/D regions.
Formation of a New Electric Material: Fullerene / Metal Polycrystalline Film
Authors: Xu BingShe , Tanaka Shun-Ichiro
Published: April 2011

An investigation of the formation behavior and mechanism of onion like fullerene / metal polycrystalline film under electron beam irradiation is presented. Metallic nanoparticles of Al, Au and Pt having diameters of 1∼35 nm, were supported on an amorphous carbon film with thickness of about 20 nm. The amorphous carbon film transformed into onion-like fullerene film under electron beam irradiation, with intensity about 1020e/cm2·sec using high resolution transmission electron microscopy. The transformation mechanism and growth morphology have been investigated. It is found that the nucleation and growth process of onion-like fullerenes from amorphous carbon were divided into several steps: Firstly, a few elliptic shells of carbon were induced under Al, Au or Pt nanoparticles; secondly, a gradual reorganization took place into the structures composed of quasi-concentric spheroid or sphered graphite, i.e., onion like fullerenes, and finally, fullerenes were bonded to each other into a film.
Analysis of Deformation of Porous Metals
Authors: Lee Dong Nyung , Han Heung Nam , Oh Kyu Hwan , Kim Hyoung Seop
Published: April 2011

The elasto-plastic finite element method using a yield criterion advanced by Lee and Kim was employed to analyze the effect of indenting geometry on the Brinell hardness of sintered porous copper specimens with various densities. The changes in geometry of porous iron rings with various initial relative densities were also calculated for various friction coefficients between the metal rings and compression platens. The calculated hardness values were in very good agreement with the measured data. The friction coefficient could be determined from the relationship between the change in the inner diameter and height reduction of porous metal rings with various initial relative densities.
Mesoscopic Simulation of Dislocation Activity at Crack Tips
Authors: Hartmaier A. , Gumbsch P.
Published: April 2011

Discrete dislocation dynamics simulations have been performed to study dislocation activity in the vicinity of a crack tip and to get a better understanding of the decisive mechanisms of the brittle-to-ductile transition (BDT). The comparison of these simulations with fracture experiments on tungsten single crystals leads to a preliminary model for the BDT of this material. Many features predicted by this model are also found in other materials. Dislocation nucleation and the availability of active sources are shown to be limiting plasticity at low temperatures and partly in the semi-brittle regime. At elevated temperatures dislocation nucleation occurs easily, such that plasticity in this regime and the BDT itself, must be viewed as a thermally activated processes, which are controlled by dislocation mobility.
Vacuum Ultraviolet Annealing of Tantalum Oxide Films Deposited at Room Temperature by Photo-Induced Cvd
Authors: Zhang J.-Y. , Boyd I.W.
Published: April 2011

In this paper, we report the effect of vacuum ultraviolet (VUV) annealing of tantalum oxide films deposited on Si (100) and quartz at room temperature by photo-induced chemical vapour deposition using excimer lamps. The influences of annealing pressure and temperature on the structural and optical properties have been studied using ellipsometry, Fourier transform infrared spectroscopy (FTIR) and UV spectrophotometry. Under optimum annealing conditions, the refractive index of the films was found to be around 2.15, while a dielectric constant of 24, a breakdown field of 2.3 MV/cm and an optical transmittance in the visible region of the spectrum greater than 85% were obtained.
Electronic States of Self-Assembled Quantum Dots: Symmetries in a Quantum Lens
Authors: Rodríguez Arezky H. , Trallero-Giner C. , Marín-Antuña J. , Ulloa S. E.
Published: April 2011

Electronic states in self-assembled quantum dots with a lens geometry are studied. A conformal analytical map is used to transform the quantum dot boundary into a dot with semi-spherical shape. The Hamiltonian for a carrier confined in the quantum lens is also mapped into an equivalent operator and its eigenvalues and eigenfunctions for the corresponding Dirichlet problem, of confinement by infinite walls, are analyzed. A modified Rayleigh-Schrddinger perturbation theory is developed to obtain analytical expressions for the energy levels and wavefunctions depending on the height b and radius a of the circular cross section of the spherical cap lens. Numerical calculations are shown for typical cases. The effects of decreasing rotational symmetry on the energy states and eigenfunctions of the quantum dot with lens-shape are presented: The degeneracy due to the z-component of the angular momentum m is broken for b ∦ a. Energy states and wavefunctions with m = 0 present the most pronounced influence on the b ∦ a case. Analytical expressions presented here can be used to estimate the sizes of actual self-assembled quantum dots.
Growth and Characterization of Gan Bulk Crystals Via Vapor Phase Transport
Authors: Shin H. , Thomson D. B. , Miraglia P. Q. , Wolter S. D. , Schlesser R. , Sitar Z. , Davis R. F.
Published: April 2011

Free-standing single crystals of bulk GaN were grown via unseeded vapor phase transport at 1130°C on hexagonal BN surfaces via direct reaction of Ga with ammonia. The number of nucleation events was reduced and the crystal size increased by introducing the ammonia at high temperatures. The resulting crystals were either needles or platelets depending on the process variables employed. Low V/III ratios achieved via ammonia flow rates ≤ 75sccm and/or ammonia total pressures ≤ 430Torr favored lateral growth. The average lateral growth rate for the platelets was ∼50μm/hr; the average vertical growth rate for the needles was ∼500μm/hr. Growth rates in all other directions for each of these two morphologies were very low. Seeded growth of both needle and platelet crystals was also achieved; however, the growth rate decreased at longer times and higher pressures due to reaction with H2 from the increased decomposition of ammonia. Nitrogen dilution suppressed this decomposition. A 2mm × 1.5mm GaN crystal was grown with minimal decomposition in a 66.7%NH3 and 33.3%N2 gas mixture.
Cathodoluminescence and Micro-Structure of Polycrystalline GaN Grown on ZnO/Si
Authors: Araki Tsutomu , Kagatsume Hidetaka , Aono Hiroaki , Nanishi Yasushi
Published: April 2011

We have investigated relationships between microscopic structure and cathodoluminescence (CL) property of polycrystalline (poly-) GaN grown by electron-cyclotron-resonance plasma-excited molecular beam epitaxy (ECR-MBE) on ZnO/Si substrates. Very strong CL with a peak of 3.45 eV was observed from the poly-GaN, which mainly showed a columnar structure with a size of 50-100 nm. On the other hand, the intensity of CL from the poly-GaN with few columnar domains was weaker than that of the poly-GaN with the columnar structure. The CL image from the poly-GaN, in which the columnar domains were locally observed, showed a strong contrast between bright domains and a dark background. It is confirmed that these bright regions in the CL images are corresponding to the columnar domains of the poly-GaN, by comparing with the SEM images. These results suggest that the columnar domains are responsible for the strong CL from the poly-GaN grown on the ZnO/Si substrates. Cross-sectional transmission electron microscope (TEM) observation revealed that the columnar domains had high quality crystallinity with few defects.
Film Properties of High-Performance FSG Films
Authors: Yoda T. , Miyajima H. , Fujita K. , Nakata R. , Nishiyama Y.
Published: April 2011

An advanced FSG film of k=3.4 was developed, which exhibited excellent resistance for moisture absorption. Physical and chemical properties of this advanced FSG film were compared by typical FSG films deposited in both high density plasma (HDP) and PE-CVD reactors, for the same k value.

The advanced FSG film appears to be superior to the HDP-FSG film by a wide margin in the following tests. The moisture absorption rate by TDS (after 4 days of air exposure) is about 5 times lower, the hardness was 1.8 times more, and the hygroscopicity (after 1 hr. boiling) was 2.6 times lower.

We conclude that these differences are mainly due to the unique film structure of the advanced FSG film.
Associação entre violência por parceiro íntimo contra a mulher e infecção por HIV
Authors: Barros Claudia , Schraiber Lilia Blima , França-Junior Ivan
Published: March 2011

OBJETIVO: Analisar a associação entre a violência por parceiro íntimo contra mulheres e a infecção ou suspeita de infecção pelo vírus da imunodeficiência humana (HIV). MÉTODOS: Estudo transversal com base em dados de questionários aplicados face-a-face e de prontuários médicos de 2.780 mulheres de 15 a 49 anos, atendidas em unidades do sistema único de saúde da Grande São Paulo, SP, em 2001-2002. As mulheres foram categorizadas em: usuárias em tratamento por serem "soropositivas para o HIV", com "suspeita de HIV" e aquelas que procuraram os serviços por outros motivos. A violência por parceiro íntimo contra mulheres na vida foi categorizada por gravidade e recorrência dos episódios de violência. A associação com o desfecho foi testada pelo modelo de Poisson com variância robusta e ajustada por variáveis sociodemográficas, sexuais e reprodutivas. RESULTADOS: A prevalência de violência foi de 59,8%. Sofrer violência reiterada e grave apresentou maior associação de infecção confirmada pelo HIV (RP = 1,91). A violência independente da gravidade e da recorrência dos episódios apresentou maior associação para a suspeita de infecção por HIV (RP = 1,29). CONCLUSÕES: A violência por parceiro íntimo contra mulheres tem papel relevante nas situações de suspeita e confirmação da infecção pelo HIV, sendo essencial incluir sua detecção, controle e prevenção como parte da atenção integral à saúde das mulheres.
Fatores associados ao consumo regular de refrigerante não dietético em adultos de Pelotas, RS
Authors: Rombaldi Airton José , Neutzling Marilda Borges , Silva Marcelo Cozzensa da , Azevedo Mario Renato , Hallal Pedro Curi
Published: March 2011

OBJETIVO: Analisar fatores associados ao consumo regular de refrigerantes não dietéticos por adultos. MÉTODOS: Estudo transversal de base populacional com 972 adultos (20 a 69 anos) do município de Pelotas, RS, realizado em 2006. A freqüência de consumo nos 12 meses anteriores à pesquisa foi medida por meio da pergunta: "em geral desde o  do ano passado, quantas vezes tu tomaste refrigerante não dietético?". As respostas categorizadas foram dicotomizadas para fins de análise. Foi considerado consumo regular de refrigerante não dietético a freqüência de cinco ou mais vezes por semana. A associação entre o desfecho e variáveis demográficas, socioeconômicas, comportamentais e nutricionais foi analisada pelo teste qui-quadrado para heterogeneidade e tendência linear e a análise multivariável foi realizada por meio de regressão de Poisson, com variância robusta. RESULTADOS: Cerca de um quinto da população adulta de Pelotas (20,4%) ingeria regularmente refrigerante não dietético. Indivíduos do sexo masculino (RP 1,50; IC95%: 1,20;2,00), fumantes atuais (RP 1,60; IC95%: 1,20;2,10) e que consumiam semanalmente lanches (RP 2,10; IC95%: 1,60;2,70) apresentaram maior prevalência de consumo de refrigerantes não dietéticos na análise ajustada. A análise estratificada por sexo mostrou que o consumo regular de frutas, legumes e verduras foi fator protetor ao consumo de refrigerantes entre mulheres (RP 0,50; IC95%: 0,30;0,90). CONCLUSÕES: A freqüência do consumo regular de refrigerantes não dietéticos na população adulta foi elevada, particularmente entre homens, jovens e fumantes.
Estudo exploratório de custos e conseqüências do pré-natal no Programa Saúde da Família
Authors: Vidal Suely Arruda , Samico Isabella Chagas , Frias Paulo Germano de , Hartz Zulmira Maria de Araújo
Published: March 2011

OBJETIVO: Avaliar custos e conseqüências da assistência pré-natal na morbimortalidade perinatal. MÉTODOS: Estudo avaliativo com dois tipos de análise - de implantação e de eficiência, realizado em 11 Unidades de Saúde da Família do Recife, PE, em 2006. Os custos foram apurados pela técnica activity-based costing e a razão de custo-efetividade foi calculada para cada conseqüência. As fontes de dados foram sistemas de informação do Ministério da Saúde e planilhas de custos da Secretaria de Saúde do Recife e do Instituto de Medicina Integral Prof. Fernando Figueira. As unidades de saúde com pré-natal implantado ou parcial foram comparadas quanto ao seu custo-efetividade e resultados perinatais. RESULTADOS: Em 64% das unidades, o pré-natal estava implantado com custo médio total de R$ 39.226,88 e variação de R$ 3.841,87 a R$ 8.765,02 por Unidade de Saúde. Nas unidades parcialmente implantadas (36%), o custo médio total foi de R$ 30.092,61 (R$ 4.272,12 a R$ 11.774,68). O custo médio por gestante foi de R$ 196,13 com pré-natal implantado e R$ 150,46 no parcial. Encontrou-se maior proporção de baixo peso ao nascer, sífilis congênita, óbitos perinatais e fetais no grupo parcialmente implantado. CONCLUSÕES: Pré-natal é custo-efetivo para várias conseqüências estudadas. Os efeitos adversos medidos pelos indicadores de saúde foram menores nas unidades com pré-natal implantado. O custo médio no grupo parcialmente implantado foi mais elevado, sugerindo possível desperdício de recursos, uma vez que a produtividade das equipes é insuficiente para a capacidade instalada.
Perspectivas culturais sobre transmissão e tratamento da tuberculose entre os Xavánte de Mato Grosso, Brasil
Authors: Welch James R. , Coimbra Jr. Carlos E. A.
Published: March 2011

Esta nota tem por objetivo apresentar os resultados preliminares de uma pesquisa em andamento sobre as perspectivas Xavánte acerca da tuberculose (TB) e suas implicações para o tratamento e controle da endemia. Entrevistas na Terra Indígena Pimentel Barbosa, Mato Grosso, Brasil, revelaram a existência de múltiplos modelos explicativos para a doença. Os Xavánte destacam a feitiçaria (simi'õ ou abzé) e os micróbios como as principais causas de TB. Dessa forma, fazem uso de fitoterápicos assim como seguem a quimioterapia prescrita pela biomedicina. Entre os Xavánte, a cultura indígena não é impeditiva para a execução das medidas preconizadas pelo Programa Nacional de Controle da Tuberculose (PNCT), pois esta não conflita com a biomedicina. Pelo contrário, os Xavánte demonstram interesse nos exames, aceitam a vacinação com BCG, comparecem às consultas e seguem a quimioterapia prescrita. Como contraponto, importantes atividades previstas no PNCT não são realizadas pelos serviços locais, ou o são de forma incompleta, comprometendo as prioridades de detecção precoce e tratamento adequado de novos casos da doença.
Condições socioeconômicas e câncer de cabeça e pescoço: uma revisão sistemática de literatura
Authors: Boing Antonio Fernando , Antunes José Leopoldo Ferreira
Published: March 2011

O presente estudo teve como objetivo descrever as principais características dos estudos epidemiológicos que investigaram a associação entre condições socioeconômicas e câncer de cabeça e pescoço. Foram pesquisadas as bases de dados Medline (Literatura Internacional em Ciências), Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) e Scielo (Scientific Electronic Library Online), além de referências citadas nos artigos obtidos a partir da busca primária nessas bases. O período de publicação considerado englobou 38 anos (1970-2007) e a análise restringiu-se aos artigos em espanhol, inglês ou português. Foram selecionados 25 estudos, 15 com delineamento caso-controle, quatro ecológicos e seis que mesclaram informações de bases de dados oficiais, como censos e registros de câncer ou de óbitos. A maior parte das pesquisas reportou associação entre piores condições socioeconômicas e câncer de cabeça e pescoço. Os indicadores mais empregados foram a ocupação e a escolaridade. Poucos estudos investigaram mediação, procurando evidenciar quais os fatores proximais operam na associação investigada. Pesquisas adicionais, com critérios uniformes para proceder aos ajustes nos modelos de regressão e amostra suficiente, são necessárias para investigar essa dimensão.
Três anos de acidentes do trabalho em uma metalúrgica: caminhos para seu entendimento
Authors: Gonçalves Cláudia Giglio de Oliveira , Dias Adriano
Published: March 2011

O objetivo deste artigo é descrever, através de estratégias metodológicas quantitativas e qualitativas, os acidentes do trabalho ocorridos em três anos numa indústria metalúrgica do interior de São Paulo para compreender suas possíveis causas. Trata-se de um estudo de casos de uma indústria; foram estudados 336 acidentes em três anos, utilizando-se três procedimentos: análise dos registros dos acidentes, entrevistas (166 acidentados) e realização de grupos focais (111 trabalhadores). A proporção de incidência anual dos acidentes foi de 16,9%; 75 casos com afastamento superior a 15 dias; 51,2% ocorreram pela manhã, afetando caldeireiros (48,2%). Entre os entrevistados, escolaridade média de 8,8 anos e idade de 31 a 50 anos (55,4%); 64,5% já haviam sofrido outros acidentes e com maior ocorrência naqueles expostos ao ruído intenso (mais 90 dBA) (53%). Nos grupos focais, identificaram-se percepções e sentimentos dos trabalhadores a respeito dos acidentes que não apareceram nas etapas anteriores. Através dos grupos focais pode-se identificar melhor os fatores que contribuem para os acidentes, como: pressões, realização de horas extras, baixos salários, condições de trabalho precárias e organização do trabalho.
Multiple Aminotransferase Peak Levels After Acute Acetaminophen Overdose in Three Patients
Authors: Rhyee Sean H. , Hoppe Jason , Heard Kennon
Published: March 2011

After acetaminophen overdose, typical trends of aspartate and alanine aminotransferase (AST and ALT, respectively) levels consist of a single peak followed by a decrease to baseline. Based on this pattern, declining AST or ALT levels have been proposed as a criterion for when to discontinue N‐acetylcysteine therapy in patients with acetaminophen overdose. We describe three patients who experienced multiple aminotransferase peak levels after acetaminophen overdose. In each case, an initial peak was followed by a 20% or greater decrease in AST or ALT level, then a second, higher peak exceeding 1000 U/L. In two cases, the second peak correlated with encephalopathy or coagulopathy. Two patients were treated with a continuous infusion of intravenous N‐acetylcysteine, with treatment interrupted for 4 hours in one of them. As observed in the three patients, multiple aminotransferase peak levels can occur after acetaminophen overdose. Although declining levels typically coincide with clinical improvement, the presence of other markers of liver injury, such as coagulopathy or encephalopathy, should prompt continued N‐acetylcysteine treatment.
Lisinopril‐Induced Nightmares
Authors: Brockman Megan M. , Trewet CoraLynn B. , Danley Dana L.
Published: March 2011

Drug‐induced nightmares have been reported in the literature and are a known adverse effect of certain antihypertensive agents such as α‐agonists and β‐blockers. Data are limited, however, on the association of this adverse effect with angiotensin‐converting enzyme (ACE) inhibitors. We describe a 63–year‐old, obese woman, with no history of illicit drug abuse, alcohol abuse, or psychiatric illness, who developed nightmares after starting lisinopril 10 mg/day for blood pressure control. The drug was discontinued, triamterene‐hydrochlorothiazide was started, and her nightmares ceased. One year later, the patient continued to have no complaints of nightmares. At that time, however, her blood pressure was slightly elevated. Triamterene was discontinued, and lisinopril was restarted at a lower dose of 5 mg/day in addition to hydrochlorothiazide 25 mg/day. Her nightmares returned; however, the patient decided to continue taking the lisinopril and tolerate the nightmares. Use of the Naranjo adverse drug reaction probability scale indicated a probable relationship (score of 6) between the patient's development of nightmares and lisinopril therapy. The exact mechanism by which ACE inhibitors cause this drug reaction is not known. Clinicians should be aware of this potential adverse effect when monitoring patients receiving ACE inhibitors.
Bivalirudin Use During Radiofrequency Catheter Ablation Procedures in Two Patients with a History of Heparin‐Induced Thrombocytopenia
Authors: Baetz Brooke E. , Gerstenfeld Edward P. , Kolansky Daniel M. , Spinler Sarah A.
Published: March 2011

Current guidelines recommend using bivalirudin, a direct thrombin inhibitor, as a preferred alternative to unfractionated heparin in patients with heparin‐induced thrombocytopenia (HIT) for percutaneous coronary intervention, as well as for cardiac and vascular surgery. Anticoagulation during radio‐frequency catheter ablation (RFA) procedures may be another potential use for bivalirudin in the setting of HIT. Radiofrequency catheter ablation procedures involving left atrial or left ventricular access are increasingly employed as a method to treat cardiac arrhythmias. Because stroke risk is a serious complication of RFA, anticoagulation is required during this procedure. We describe the first report, to our knowledge, of successful use of bivalirudin anticoagulation during RFA procedures in two patients with a history of clinically diagnosed HIT that precluded the use of unfractionated heparin or low‐molecular‐weight heparin. One of the patients underwent RFA for ventricular tachycardia, the other for pulmonary vein isolation for the treatment of atrial fibrillation. In both patients, bivalirudin was administered as a 0.75–mg/kg intravenous bolus, followed by a 1.75–mg/kg/hour infusion. Activated clotting time (ACT) was measured after the initial bolus in each patient. However, no dosage adjustment was made based on the ACT, and the infusion rate of bivalirudin remained fixed during the procedures. Both procedures were completed without any embolic events. No bleeding or clotting events were noted; one patient experienced minor access site oozing that was not felt to be clinically important. Bivalirudin is a therapeutic option for anticoagulation during left‐sided catheter RFA procedures in patients with a history of HIT.
Current and Future Clinical Strategies in the Management of Chronic Myeloid Leukemia
Authors: Rao Kamakshi V. , Iannucci Andrea , Jabbour Elias
Published: March 2011

Rational design of tyrosine kinase inhibitors, such as imatinib, against leukemogenic Bcr‐Abl kinase has resulted in unprecedented responses and survival rates in patients with chronic myeloid leukemia (CML). Although these responses are sustained for years in the majority of patients, a fraction of the patients either fail or respond suboptimally to imatinib therapy, or are intolerant to the drug. Biologic insights into the mechanisms of imatinib resistance led to the development of several strategies, including dose escalation and second‐generation tyrosine kinase inhibitors. Dasatinib and nilotinib are second‐generation tyrosine kinase inhibitors that are approved as second‐line treatment for imatinib‐resistant patients based on their activity in these patients and their favorable toxicity profiles. Dasatinib and nilotinib have demonstrated promising activity as front‐line therapy and are being directly compared with imatinib therapy in this setting. Salvage treatment options are evolving for patients with CML, with several novel agents showing promising activity, even in patients with the noted T315I mutation. The role of stem cell transplantation for patients with CML is being redefined in the context of significant transplantation‐related morbidity and mortality and the availability of effective alternate therapies. In this context, practical considerations such as guidelines for monitoring responses to imatinib therapy, criteria for choice of second‐line therapy, management of the adverse events of tyrosine kinase inhibitors, and quality‐of‐life issues are of particular importance. This review summarizes recent advances in the treatment of CML over the past decade, with an emphasis on tyrosine kinase inhibitor therapy.
Blood Loss Control with Two Doses of Tranexamic Acid in a Multimodal Protocol for Total Knee Arthroplasty
Authors: Ortega-Andreu Miguel , Pérez-Chrzanowska Hanna , Figueredo Reyes , Gómez-Barrena Enrique
Published: March 2011

Average blood loss after total knee arthroplasty (TKA) usually ranges from 1500 to 1900 cc, including both the postoperative drain and hidden blood loss. This represents about 46% of TKA patients requiring postoperative blood transfusion. Not only the risks of disease transmission but also those of ABO incompatibility, infection due to immunosupression, increased procedure costs, and increased length of hospital stay, are potential problems that foster blood saving strategies. In this study, 71 unilateral TKAs using a multimodal protocol to decrease blood loss were compared to 61 historical cases. Patients in both groups underwent cemented TKA with the same system, surgical technique, and multimodal protocol (MIS approach, plug in the femoral canal, tourniquet removal after wound closure and compressive bandage, analgesic periarticular infiltration with vasoconstrictor, postoperative drain at atmospheric pressure, opened 2 hours after the end of the surgical procedure and removed after 24 hours). The study series incorporated intravenous tranexamic acid (TXA) infusion in 2 doses of 10-15 mg/kg, 15 minutes before tourniquet release and 3 hours later. Results showed no transfusion requirements in the TXA series (0%), with 23/61 (37.7%) transfusions in the control, with an average cost decrease of 240 euros per patient. Visible bleeding in 24h significantly decreased from 553.36 cc (range 50-1500) to 169.72 cc (range 10-480) in the TXA series. As a conclusion, implementing a TXA-based multimodal protocol produced significant decrease in the transfusion rate, visible blood loss, and cost per patient, thus proving effectiveness and efficiency in the surgical management of TKA.
Biocompatibility and Bone Formation of Flexible, Cotton Wool-like PLGA/Calcium Phosphate Nanocomposites in Sheep
Authors: Schneider Oliver D , Mohn Dirk , Fuhrer Roland , Klein Karina , Kämpf Käthi , Nuss Katja M.R , Sidler Michèle , Zlinszky Katalin , Rechenberg Brigitte von , Stark Wendelin J
Published: March 2011

Background:

The purpose of this preliminary study was to assess thein vivoperformance of synthetic, cotton wool-like nanocomposites consisting of a biodegradable poly(lactide-co-glycolide) fibrous matrix and containing either calcium phosphate nanoparticles (PLGA/CaP 60:40) or silver doped CaP nanoparticles (PLGA/Ag-CaP 60:40). Besides its extraordinaryin vitrobioactivity the latter biomaterial (0.4 wt% total silver concentration) provides additional antimicrobial properties for treating bone defects exposed to microorganisms.

Materials and Methods:

Both flexible artificial bone substitutes were implanted into totally 16 epiphyseal and metaphyseal drill hole defects of long bone in sheep and followed for 8 weeks. Histological and histomorphological analyses were conducted to evaluate the biocompatibility and bone formation applying a score system. The influence of silver on thein vivoperformance was further investigated.

Results:

Semi-quantitative evaluation of histology sections showed for both implant materials an excellent biocompatibility and bone healing with no resorption in the adjacent bone. No signs of inflammation were detectable, either macroscopically or microscopically, as was evident in 5 µm plastic sections by the minimal amount of inflammatory cells. The fibrous biomaterials enabled bone formation directly in the centre of the former defect. The area fraction of new bone formation as determined histomorphometrically after 8 weeks implantation was very similar with 20.5 ± 11.2 % and 22.5 ± 9.2 % for PLGA/CaP and PLGA/Ag-CaP, respectively.

Conclusions:

The cotton wool-like bone substitute material is easily applicable, biocompatible and might be beneficial in minimal invasive surgery for treating bone defects.
Total Elbow Arthroplasty
Authors: Sanchez-Sotelo Joaquin
Published: March 2011

Total elbow arthroplasty has continued to evolve over time. Elbow implants may be linked or unlinked. Unlinked implants are attractive for patients with relatively well preserved bone stock and ligaments, but many favor linked implants, since they prevent instability and allow replacement for a wider spectrum of indications. Inflammatory arthropathies such as rheumatoid arthritis represent the classic indication for elbow arthroplasty. Indications have been expanded to include posttraumatic osteoarthritis, acute distal humerus fractures, distal humerus nonunions and reconstruction after tumor resection. Elbow arthroplasty is very successful in terms of pain relief, motion and function. However, its complication rate remains higher than arthroplasty of other joints. The overall success rate is best for patients with inflammatory arthritis and elderly patients with acute distal humerus fractures, worse for patients with posttraumatic osteoarthritis. The most common complications of elbow arthroplasty include infection, loosening, wear, triceps weakness and ulnar neuropathy. When revision surgery becomes necessary, bone augmentation techniques provide a reasonable outcome.
Internal corrosion of carbon steel piping in hot aquifers service
Authors: Simicic Milos , Govedarica Dragan
Published: March 2011

Internal corrosion of carbon steel pipelines is a major problem encountered
in water service. In terms of prediction of the remaining lifetime for water
pipelines based on the corrosion allowance, the three main approaches are
corrosion modelling, corrosion inhibitor availability, and corrosion
monitoring. In this study we used two theoretical corrosion models, CASSANDRA
and NORSOK M-506 of quite different origin in order to predict uniform
corrosivity of hot aquifers in eight different pipelines. Because of the
varying calculation criteria for the different models, these can give very
different corrosion rate predictions for the same data input. This is
especially true under conditions where the formation of protective films may
occur, such as at elevated temperatures. The evaluation of models was
conducted by comparison using weight-loss coupons and three corrosion
inhibitors were obtained from commercial suppliers. The tests were performed
during the 60-day period. Even though inhibitors? efficiencies of 98% had
been achieved in laboratory testing, inhibitors? availabilities of 85% have
been used due to logistics problems and other issues. The results, given in
mmpy, i.e. millimeter per year, are very consistent with NORSOK M-506
prediction. This is presumably because the model considers the effect of the
formation of a passive iron carbonate film at temperatures above 80 ?C and
significant reduction in corrosion rate. Corrosion inhibitor A showed a
better performance than inhibitors B and C in all cases but the target
corrosion rates of less than 0.1 mmpy were achieved for all inhibitors. The
chemical type of corrosion inhibitor A is based on quaternary amines mixed
with methanol, isopropyl alcohol, xylene and ethylbenzene. Based on the
obtained results the carbon steel lifetime of 30 years, provided proper
inhibitors are present and 3mm corrosion allowance, can be achieved for hot
aquifers service with presented water compositions.
Functional Sympatholysis During Exercise in Patients With Type 2 Diabetes With Intact Response to Acetylcholine
Authors: Thaning Pia , Bune Laurids T. , Zaar Morten , Saltin Bengt , Rosenmeier Jaya B.
Published: March 2011

OBJECTIVE

Sympathetic vasoconstriction is blunted in contracting human skeletal muscles (functional sympatholysis). In young subjects, infusion of adenosine and ATP increases blood flow, and the latter compound also attenuates α-adrenergic vasoconstriction. In patients with type 2 diabetes and age-matched healthy subjects, we tested 1) the sympatholytic capacity during one-legged exercise, 2) the vasodilatory capacity of adenosine and ATP, and 3) the ability to blunt α-adrenergic vasoconstriction during ATP infusion.

RESEARCH DESIGN AND METHODS

In 10 control subjects and 10 patients with diabetes and normal endothelial function, determined by leg blood flow (LBF) response to acetylcholine infusion, we measured LBF and venous NA, with and without tyramine-induced sympathetic vasoconstriction, during adenosine-, ATP-, and exercise-induced hyperemia.

RESULTS

LBF during acetylcholine did not differ significantly. LBF increased ninefold during exercise and during adenosine- and ATP-induced hyperemia. Infusion of tyramine during exercise did not reduce LBF in either the control or the patient group. During combined ATP and tyramine infusions, LBF decreased by 30% in both groups. Adenosine had no sympatholytic effect.

CONCLUSIONS

In patients with type 2 diabetes and normal endothelial function, functional sympatholysis was intact during moderate exercise. The vasodilatory response for adenosine and ATP did not differ between the patients with diabetes and the control subjects; however, the vasodilatory effect of adenosine and ATP and the sympatholytic effect of ATP seem to decline with age.