bluuebunny/crossref_metadata_2025 huggingface dataset:
Randomized Phase II Study of Ixabepilone or Paclitaxel Plus Carboplatin in Patients With Non–Small-Cell Lung Cancer Prospectively Stratified by Beta-3 Tubulin Status
Authors: Edelman Martin J. , Schneider Claus-Peter , Tsai Chun-Ming , Kim Heung-Tae , Quoix Elisabeth , Luft Alexander V. , Kaleta Remigiusz , Mukhopadhyay Pralay , Trifan Ovidiu C. , Whitaker Laura , Reck Martin
Published: April 2013

Purpose

Retrospective studies have reported that tumor expression of the beta-3 tubulin (β3T) isoform is an unfavorable prognostic factor in non–small-cell lung cancer (NSCLC) treated with tubulin-inhibiting chemotherapy. Ixabepilone is a tubulin-inhibiting agent with low susceptibility to multiple resistance mechanisms including β3T isoform expression in several tumor models. This randomized phase II study evaluated ixabepilone-based chemotherapy in stage IIIb/IV NSCLC, compared with paclitaxel-based chemotherapy. Tumor specimens were prospectively evaluated for β3T expression.

Patients and Methods

Patients were stratified by β3T status (positive v negative) and randomly assigned at a ratio of 1:1 to receive ixabepilone (32 mg/m2) and carboplatin (area under concentration-time curve [AUC], 6) or paclitaxel (200 mg/m2) and carboplatin (AUC, 6) for up to six cycles. The primary end point was progression-free survival (PFS) in the β3T-positive subgroup.

Results

Ninety-five patients (β3T positive, 52; β3T negative, 43) received ixabepilone plus carboplatin; 96 patients (β3T positive, 49; β3T negative, 47) received paclitaxel plus carboplatin. No significant differences in median PFS were observed between arms for either subgroup (β3T positive, 4.3 months in both arms; β3T negative, 5.8 v 5.3 months). Ixabepilone did not significantly improve overall survival (OS) for the β3T-positive subset or the overall population. Adverse events were similar between the two arms and comparable with those in previous studies.

Conclusion

There was no predictive value of β3T in differentiating clinical activity of ixabepilone- or paclitaxel-containing regimens. Ixabepilone did not improve PFS or OS in patients with β3T-positive tumors. β3T-positive patients had worse PFS relative to β3T-negative patients, regardless of treatment; hence, β3T expression seems to be a negative prognostic factor, but not a predictive factor, in advanced NSCLC treated with either ixabepilone or paclitaxel platinum-based doublets.
Role of macrophage activation in the lipid metabolism of postprandial triacylglycerol-rich lipoproteins
Authors: Napolitano Mariarosaria , Sennato Simona , Botham Kathleen M , Bordi Federico , Bravo Elena
Published: April 2013

The potential link between the inflammatory effects of postprandial lipemia and the induction of macrophage foam cell formation by triacylglycerol-rich lipoproteins (TGRL) was studied using postprandial triacylglycerol-rich lipoproteins (ppTGRL) derived from human volunteers and primary human monocyte-derived macrophages (HMDM). Subjects were fed a test meal high in dairy fat, followed three hours later by isolation of serum ppTGRL. Pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes were induced in HMDM by treatment with lipopolysaccharide (LPS) or dexamethasone (DEX), respectively. ppTGRL caused a dose-dependent increase in both triacylglycerol (TG) and cholesterol (CH) accumulation in the cells. TG accumulation was unaffected by LPS or DEX treatment, but LPS as compared with DEX-treated HMDM were found to accumulate more CH, and this effect was greater than that induced by ppTGRL in untreated cells. LPS-treatment had no effect on lipid uptake from ppTGRL (via the LDLr, scavenger receptors or SR-B1) or on CH efflux, but the CH synthesis inhibitor mevinolin abolished the difference between CH accumulation in LPS-and DEX-treated cells, suggesting that CH synthesis is enhanced in the inflammatory state. Phospholipid (PL) synthesis was increased in inflammatory M1 as compared with anti-inflammatory M2 HMDM. Moreover, TG synthesis was decreased by ppTGRL in DEX-treated as compared with untreated cells. We conclude, therefore, inflammation causes a greater increase in the accumulation of neutral lipids than ppTGRL in macrophages, and that this effect is related to modulation of PL metabolism and possibly also CH synthesis. Thus, the inflammatory phenotype of macrophages influences their lipid metabolism, and is, therefore, likely to modulate the induction of macrophage lipid accumulation by lipoproteins associated with foam cell formation.
Rhabdomyosarcomatous differentiation in gastrointestinal stromal tumors after imatinib resistance: a potential diagnostic pitfall
Authors: Zheng Song , Huang Ke-er , Jia Jing , Xin Li , Tao De-You
Published: April 2013

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the digestive tract and characterized by expression of protein-tyrosine kinase (KIT) protein. Treatment of advanced GISTs has been improved dramatically following the development of imatinib. Despite the often long-lasting clinical benefit seen in most patients treated with imatinib, many will eventually suffer disease progression. In general, progressing GISTs retain their typical morphology. In this study, we present a patient with metastatic GISTs, who received more than 16 months of treatment with imatinib and whose tumors changed their morphological and immunohistochemical characteristics after imatinib-resistance. Histological, immunohistochemical and mutational analysis was performed on the prior and post-imatinib treatment GIST samples. The imatinib-resistant tumor cells in the progressing metastases showed marked pleomorphism which proved to be rhabdomyoblastic differentiation with Desmin and Myogenin immunopositivity. However, there was no secondary mutation of KIT, PDGFRA, KRAS and BRAF genes found in the imatinib-resistant lesion, except primary KIT V559D mutation. To our knowledge, this case represents the few reports on this unusual type of transdifferentiation in GISTs under imatinib therapy. Awareness of this phenomenon would help to avoid diagnostic confusion when evaluating post-imatinib samples from GISTs.
Chitosan/poly(vinyl alcohol) hydrogel combined with Ad-hTGF-β1 transfected mesenchymal stem cells to repair rabbit articular cartilage defects
Authors: Qi Bai-Wen , Yu Ai-Xi , Zhu Shao-Bo , Zhou Min , Wu Gang
Published: April 2013

The aim of this work is to explore the feasibility and therapeutic effect of repairing rabbit articular cartilage defects using thermo-sensitive chitosan/poly (vinyl alcohol) composite hydrogel engineered Ad-hTGF-β1-transfected bone marrow mesenchymal stem cells. Rabbit's bone marrow stromal cells (BMSCs) were obtained and cultured in vitro and transfected with a well-constructed Ad-hTGF-β1 vector, the cartilage phenotype of the transfected cells was tested by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Twenty-four New Zealand white rabbits with articular cartilage defects were randomly divided into four groups: group A was treated with CS/PVA gel and transfected BMSCs; group B received CS/PVA gel and un-transfected BMSCs; group C was treated with CS/PVA gel alone and group D was the untreated control group. Experimental animals of each group were killed at 16 weeks after operation. General observation, Masson's trichrome staining and collagen II immunohistological staining of the specimens were performed to evaluate the repair effect. The Wakitani scoring method was used to evaluate the repair effect. RT-PCR and Western blot confirmed that the hTGF-β1 gene was expressed in BMSCs and triggered the expression of specific markers of cartilage differentiation such as aggrecan mRNA and Collagen II in BMSCs after transfection with Ad-hTGF-β1. Sixteen weeks after operation, the defects in group A had smooth and flat surfaces, and the defects appeared to have completely healed, exhibiting almost the same color and texture as the surrounding cartilage. Masson's trichrome staining showed that the cell arrangement and density of regenerated cartilage tissue in group A was not significantly different from that of normal cartilage tissue. The immunohistochemical staining of Col II showed a strong expression in group A and weak expression in group B, but no expression in groups C and D. According to the Wakitani score, the difference between experimental group A and all of the other groups was statistically significant (P, 0.01). To conclude, as a thermosensitive and injectable scaffold material, CS/PVA gel engineered with BMSCs transfected with hTGF-β1 can effectively repair rabbit articular cartilage defects.
High-fat, cholesterol-rich diet affects leptin expression in the aortic layers
Authors: KrawczyńSka Agata , Olczak Elzbieta , Rembiszewska Alina , Gromadzka-Ostrowska Joanna
Published: April 2013

Leptin is stated to be an important mediator between obesity and cardiovascular disease. However, whether leptin location in the aorta is dependent on diet and its atherogenic character is still unknown. This study examined the relationship between a high-fat diet with or without cholesterol and the expression of leptin in aortic layers. Forty male rats were fed a high-fat diet with fish or grape seed oil as a dietary fat source, with or without cholesterol, to enhance the atherogenic character of their diet. The experiments lasted for three and six weeks, respectively. Plasma lipid profile, plasma leptin concentration and leptin expression in the endothelium (E), myometrium (M) and adventitia (A) were examined. The length of feeding was a key factor which influenced both the lipid profile and leptin expression in the aorta. Leptin concentration positively correlated with body weight and plasma triglycerides only in the three-week experiment, which suggests that the physiological actions of leptin can be disturbed by prolonged consumption of a high-fat diet. Short-term intake of a high-fat diet with fish oil, increasing high density lipoprotein cholesterol (HDL) level and decreasing total cholesterol (TC)/HDL ratio, enhanced leptin expression in E in comparison to the group fed grape seed oil. However, in the group with the highest diet intake, leptin expression in each layer was lowest. Generally, leptin expression was most common in E; however, an extension of the period of feeding in groups fed a diet with grape seed oil with or without additional cholesterol increased leptin presence in M and A in comparison to the group fed fish oil. Significantly higher values of TC and HDL in the same groups may suggest that leptin changes in the aorta and the atherogenic impact of grape seed oil can be connected when the consumption of a high-fat diet is excessive.
Intestinal and renal guanylin peptides system in hypertensive obese mice
Authors: Simões-Silva Liliana , Moreira-Rodrigues Mónica , Quelhas-Santos Janete , Fernandes-Cerqueira Cétia , Pestana Manuel , Soares-Silva Isabel , Sampaio-Maia Benedita
Published: April 2013

Guanylin (GN), uroguanylin (UGN) and the GC-C receptor have been associated with two endocrine axes: the salt and water homeostasis regulating enterorenal axis and the recently described appetite-regulating UGN/GC-C extraintestinal axis. The present work assessed the mRNA expression levels of GN peptides system (GPS) in a model of diet-induced obesity. Male C57BL/6J mice were submitted to either a high-fat high-simple carbohydrate diet (obese) or a normal diet (control). The renal and intestinal GN, UGN and GC-C receptor mRNA expression were evaluated by reverse transcriptase quantitative polymerase chain reaction in both groups, during normo-saline (NS) and high-saline (HS) diet. The diet-induced obesity was accompanied by glucose intolerance and insulin resistance as well as by a significant increase in blood pressure. During NS diet, obese mice presented reduced mRNA expression of GN in ileum and colon, UGN in duodenum, ileum and colon and GC-C in duodenum, jejunum, ileum and colon. This was accompanied by increased UGN mRNA expression in renal cortex. During HS diet, obese mice presented reduced mRNA expression of GN in jejunum as well as reduced mRNA expression of UGN and GC-C in duodenum, jejunum and colon. The data obtained suggest that, in a mouse model of diet-induced obesity, a down-regulation of intestinal mRNA expression of GN, UGN and its GC-C receptor is accompanied by a compensatory increase of renal UGN mRNA expression. We hypothesize that the decrease in gene expression levels of intestinal GPS may contribute to the development of hypertension and obesity during hypercaloric diet intake.
The RNA–Protein World
Authors: Altman Sidney
Published: April 2013

Following the naming of the RNA World for the hypothetical biochemical world during very early life forms, the current world was named the Protein World. However, the astonishing high level of transcripts from virtually all chromosomes in an organism now found in eucaryotes, as well as their extensive roles in regulating gene expression, suggests that today’s world should be labeled as the RNA–Protein World.
Ação de Inseticidas Botânicos sobre a Preferência Alimentar e sobre Posturas de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) em Milho
Authors: Mazzonetto Fábio , Coradini Flávia , Corbani Renato Zapparoli , Dalri Alexandre Barcellos
Published: April 2013

O presente trabalho objetivou comparar o efeito de diferentes extratos de origem vegetal na preferência alimentar e na postura da lagarta do cartucho Spodoptera frugiperda (J.E. Smith) em folhas de milho. Extratos aquosos a 10% p/v de Chenopodium ambrosioides (Linnaeus) (Erva de Santa Maria), Corymbia citriodora (Hill & Johnson) (Eucalipto Cheiroso), Chrysanthemum leucanthemum (Linnaeus) (Crisântemo) e Azadirachta indica (A. Juss) (Nim) foram aplicados em discos de folhas de milho e oferecidos às lagartas em testes com e sem chance de escolha. A atratividade das lagartas pelos discos com os extratos não diferiu da testemunha no teste com chance de escolha, porém os extratos de Nim e Crisântemo apresentaram efeito fagodeterrente a S. frugiperda. Nos testes sem chance de escolha, o tratamento que mais repeliu as lagartas foi utilizando extrato de Nim, representando possível alternativa para o controle das lagartas desta espécie. Nenhum dos extratos aquosos das espécies vegetais testadas apresentou efeito ovicida.

Action of Botanical Insecticides on the Preference of Food and on Postures of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Maize

Abstract. This study compares the effect of different extracts of vegetal origin in food preference and posture of the fall armyworm Spodoptera frugiperda (J.E. Smith) in maize leaves. Aqueous extracts 10% w/v of Chenopodium ambrosioides (Linnaeus), Corymbia citriodora (Hill & Johnson), Chrysanthemum leucanthemum (Linnaeus, 1753) and Azadirachta indica (A. Juss) were applied to leaf discs of maize and offered to caterpillars tests with and without choice. The attractiveness of the caterpillars for discs with the extracts did not differ from the control test-choice, but extracts of A. indica and C. leucanthemum showed antifeedant activity to S. frugiperda. In no-choice tests, the treatment was more repelled the larvae using A. indica extract, representing possible alternative for the control of caterpillars of this species. None of the aqueous extracts of the plant species tested showed ovicidal effect.
Use of Leaves Treated with Hydrogen Peroxide in Case-Building by Phylloicus spp. (Trichoptera: Calamoceratidae)
Authors: Vidovix Thyago Augusto da Silva , Martins Renato Tavares , Duarte Cleber , Pes Ana Maria Oliveira
Published: April 2013

The objective of this study was to assess if larvae of Phylloicus spp. show any preference for leaves with or without microorganisms when building cases. Two experiments were realized at municipality of Presidente Figueiredo (Amazonas – Brazil), containing leaves treated with Hydrogen peroxide (H2O2), a compost that has an antimicrobial action, and another one with untreated leaves. In the first were observed the case-building by larvae of Phylloicus spp. And in the second was tested the preference by treated or untreated leaves. The larvae were monitored during 24 hours and to statistical analysis was used the t-test. Were not observed significant differences in the number of discs used by the larvae in the first experiment (p=0.24; t=-0.73) and no preference by type of leaf in the second experiment (p=0.41; t=0.23). Therefore, we do not recommend the use of hydrogen peroxide in studies that aim to eliminate microorganisms from decomposing leaves.

Uso de Folhas Tratadas com Peróxido de Hidrogênio na Construção de Abrigos por Phylloicus spp. (Trichoptera: Calamoceratidae)

Resumo. O objetivo deste estudo foi avaliar se larvas de Phylloicus spp. possuem preferência por folhas com ou sem micro-organismos para a construção de abrigos. Dois experimentos foram realizados no município de Presidente Figueiredo (Amazonas – Brasil), contendo folhas tratadas com peróxido de hidrogênio (H2O2), composto que possui ação antimicrobiana, e folhas não tratadas. No primeiro observaram-se a construção de abrigos pelas larvas de Phylloicus spp. e no segundo testou-se a preferência por folhas tratadas ou não tratadas. As larvas foram monitoradas durante 24 horas e para a análise estatística foi utilizado o teste-t. Não foram observadas diferenças significativas no número de discos usados pelas larvas no primeiro experimento (p=0,24; t=-0,73) e nem na preferência pelo tipo de folha no segundo experimento (p=0,41; t=0,23). Portanto, não recomendamos o uso do peróxido de hidrogênio em estudos realizados em laboratório que visem à eliminação de micro-organismos de folhas em decomposição.
Formigas (Hymenoptera, Formicidae) Associadas a Ninhos de Cornitermes cumulans Kollar (Isoptera, Termitidae) no Cerrado do Planalto Central do Brasil
Authors: Gallego Ropero María Cristina , Machado Feitosa Rodrigo , Pujol Luz Jose Roberto
Published: April 2013

Com o objetivo de conhecer a fauna de formigas que coabita os cupinzeiros de Cornitermes cumulans (Kollar) no Cerrado sensu stricto do Brasil Central, foram realizadas coletas em 36 cupinzeiros em três localidades. Os cupinzeiros foram fragmentados e o material coletado foi armazenado em frascos com álcool a 80%. Apresentamos aqui uma lista das formigas associadas aos cupinzeiros de C. cumulans. Um total de 61 espécies distribuídas em nove subfamílias e 32 gêneros foi coletado. A subfamília Myrmicinae apresentou o maior número de gêneros (15) e de espécies (22). Estes resultados indicam que ninhos de cupins são importantes recursos de nidificação para várias espécies de formigas no Brasil Central.

Ants (Hymenoptera, Formicidae) Associated with Nests of Cornitermes cumulans (Kollar) (Isoptera, Termitidae) in the Cerrado of Central Brazil

Abstract. In order to survey the ant fauna inhabiting termite nests of Cornitermes cumulans (Kollar) in the Cerrado sensu stricto of Central Brazil, we collected inquiline ants in 36 termitaries in three localities. Termite mounds were fragmented and the ants collected and preserved in 80% ethanol. Here we present a list of the associated ants found in mounds of C. cumulans. A total of 61 species belonging to nine subfamilies and 32 genera were collected. The subfamily Myrmicinae had the largest number of genera (15) and species (22). The results indicate that termite mounds are an important nesting resource for several ant species in the Brazilian Cerrado.
The Implicit Hitting Set Approach to Solve Combinatorial Optimization Problems with an Application to Multigenome Alignment
Authors: Moreno-Centeno Erick , Karp Richard M.
Published: April 2013

We develop a novel framework, the implicit hitting set approach, for solving a class of combinatorial optimization problems. The explicit hitting set problem is as follows: given a set U and a family S of subsets of U, find a minimum-cardinality set that intersects (hits) every set in S. In the implicit hitting set problem (IHSP), the family of subsets S is not explicitly listed (its size is, generally, exponential in terms of the size of U); instead, it is given via a polynomial-time oracle that verifies if a given set H is a hitting set or returns a set in S that is not hit by H. Many NP-hard problems can be straightforwardly formulated as implicit hitting set problems. We show that the implicit hitting set approach is valuable in developing exact and heuristic algorithms for solving this class of combinatorial optimization problems. Specifically, we provide a generic algorithmic strategy, which combines efficient heuristics and exact methods, to solve any IHSP. Given an instance of an IHSP, the proposed algorithmic strategy gives a sequence of feasible solutions and lower bounds on the optimal solution value and ultimately yields an optimal solution. We specialize this algorithmic strategy to solve the multigenome alignment problem and present computational results that illustrate the effectiveness of the implicit hitting set approach.
Utility Copula Functions Matching All Boundary Assessments
Authors: Abbas Ali E.
Published: April 2013

The construction of a multiattribute utility function is an important step in decision analysis and can be a challenging task unless some decomposition of the utility function is performed. When every attribute is utility independent of its complement, the utility elicitation task is significantly simplified because the functional form of the utility function requires only one conditional utility function for each attribute, and some normalizing constants. When utility independence conditions do not hold, the conditional utility function of an attribute may vary across the domain of the complement attributes, and therefore a single conditional utility assessment for each attribute may not be sufficient to capture the decision maker's preferences. This paper proposes a method to construct utility functions that have the flexibility to match the variations in the conditional utility function, across the domain of the attributes, using univariate utility assessments at the boundary values. The approach incorporates the boundary assessments into a new function, which we call the double-sided utility copula. This formulation provides a wealth of new functional forms that the analyst may use to incorporate utility dependence in multiattribute decision problems. The utility copula function also allows for the flexibility to incorporate a wide range of trade-off assessments among the attributes, while keeping the utility assessments at the boundary values fixed. It is also useful in determining the order of approximation provided by using certain independence assumptions in a multiattribute decision problem when the attributes are utility dependent.
Flexible Server Allocation and Customer Routing Policies for Two Parallel Queues When Service Rates Are Not Additive
Authors: Ahn Hyun-Soo , Lewis Mark E.
Published: April 2013

We consider the question of how routing and allocation can be coordinated to meet the challenge of demand variability in a parallel queueing system serving two types of customers. A decision maker decides whether to keep customers at the station at which they arrived or to reroute them to the other station. At the same time, the decision maker has two servers and must decide where to allocate their effort. We analyze this joint decision-making scenario with both routing and station-dependent holding costs, but add an important twist. We allow the combined service rate (when the servers work at the same station) to be superadditive or subadditive. This captures positive or negative externalities that arise during collaboration. We seek an optimal control policy under the discounted or long-run average cost criteria.

Our results show that in the superadditive case jobs should never be routed away from the lower-cost queue. When jobs are rerouted from the higher-cost queue to the low-cost queue the optimal control is monotone in the respective queue lengths. Moreover, we show that the optimal allocation is a nonidling priority rule based on the holding costs. In the subadditive case we find that the optimal policy need not exhibit such a simple structure. In fact, the optimal allocation need not prioritize one station (it may split the servers), and the optimal routing need not be monotone in the number of customers in each queue. We characterize the optimal policy for a few canonical cases and discuss why intuitive policies need not be optimal in the general case. An extensive numerical study examines the benefit of dynamically controlling both routing and resource allocation; we discuss when using one of the two levers—dynamic routing and dynamic allocation—is sufficient and when using both controls is warranted.
Energieautarker Drucksensor für Anwendungen im Automobil
Authors: Kurth Martin
Published: April 2013

Im Rahmen dieses Beitrags wird ein energieautarkes drahtloses Sensormikrosystem vorgestellt. Die Neuheit des drahtlosen Systems besteht darin, dass es als energieautarkes Sensorsystem speziell für den Einsatz in Fahrzeugen konzipiert worden ist. Der neu entwickelte energieautarke Drucksensor soll den Förderdruck im Kraftstoffsystem von Fahrzeugen drahtlos im 2,4-GHz-Frequenzband an einen Empfänger übertragen. Das energieautarke Sensorsystem wird durch einen kinematischen Wandler mit Energie versorgt, wobei ein Messwert übertragen wird, sobald ausreichend Energie im System vorhanden ist. Somit variiert die Systemdatenrate abhängig vom Systemenergieniveau. Da diese Art der Energieversorgung keine konstante Leistung an die Schaltung abgibt, ist eine spezielle Anpassschaltung, bzw. eine Spannungsversorgungsschaltung gefunden worden, die es erlaubt, den kinematischen Energiewandler an die Sensorschaltung anzupassen. Dabei wird ein Energiespeicher so lange mit Energie versorgt, bis ein bestimmter Schwellenwert erreicht ist. Dieser Schwellenwert wurde so festgelegt, dass für einen Druck- und Temperaturmesszyklus ausreichend Energie im Speicher vorhanden ist. Nach erfolgreicher Übertragung geht die Schaltung wieder in den Zustand des “Energiesammelns” über. Um einen möglichst kompakten Systemaufbau bestehend aus Drucksensor, Energiewandler mit Energiespeicher, Controller und HF Modul realisieren zu können, wurde eine Aufbauvariante in Form eines PCB/MID Trägerrahmens untersucht und dargestellt.
Kamerabasierte quantitative Messverfahren für die Silizium-Photovoltaik — Was Licht über Solarzellen erzählt
Authors: Kasemann Martin
Published: April 2013

Dieses Paper beschreibt die physikalischen Grundlagen neuer kamerabasierter Messtechniken für die Silizium-Photovoltaik. Die Methodenentwicklung zielt vor allem darauf ab, Bildintensitäten auf physikalische Standardkenngrößen (Strom, Spannung, Widerstand, Leistung) zurückführen. Dies erhöht — zumindest im Rahmen der Gültigkeit der teilweise vereinfachten physikalischen Modelle — die Aussagekraft und Vergleichbarkeit von Ergebnissen. Ausgewählte Beispiele zeigen, dass die Verfahren sowohl relevant für die Produktionskontrolle in der Solarindustrie sind, als auch wichtige neue Einsichten in die Solarzellen- und Halbleiterphysik bieten.
Bewegungszustandsbestimmung ungestützter MEMS-Beschleunigungssensoren
Authors: Keunecke Kristoph , Scholl Gerd
Published: April 2013

Ist der Bewegungszustand autonom agierender inertialer Navigationssysteme (INS) bekannt, lässt sich die Positioniergenauigkeit durch die Anwendung sog. Zero Velocity Updates (ZUPT) deutlich erhöhen. Verschwindet das Nutzsignal der Sensoren allerdings im Rauschen, was insbesondere bei langsamen Bewegungen der Fall ist, so hat die Schätzung des Bewegungszustandes anhand klassischer Verfahren der statistischen Signalanalyse über die Interpretation von Änderungen im Rauschsignal zu erfolgen. Dazu präsentiert dieser Artikel eine umfassende Charakterisierung dieser Verfahren anhand einfacher aber typischer Testszenarien.
Optische Erfassung dreidimensionaler Strukturen in einem globalen Referenzsystem
Authors: Schmitt Robert , Schönberg Alexander , Bertelsmeier Felix
Published: April 2013

Eine Herausforderung bei der Inbetriebnahme von Produktionsprozessen liegt in der Identifikation und Kompensation von Abweichungen zwischen einer virtuellen Planung und der realen Umsetzung. Diese Abweichungen können durch globale Referenzsysteme sichtbar gemacht und kompensiert werden. Dieser Beitrag beschreibt die Integration lokaler Sensorik und deren Daten in einem globalen Referenzsysteme am Beispiel eines flexiblen Lichtschnittsensors bestehend aus mehreren Kameras und einem Mehrlinien-Laserprojektor.
Ein störgrößenunterdrückendes optisches Messsystem auf Basis von Faser-Bragg-Gitter-Sensoren
Authors: Rößner Max R. , Heßke Andre , Kin Vitali , Koch Alexander W.
Published: April 2013

Faser-Bragg-Gitter können als optische Temperatur- und Dehnungssensoren, die in den Kern einer Glasfaser eingeschrieben sind, betrieben werden [1]. In bestimmten Anwendungen bieten sie Vorteile gegenüber konventionellen, elektrischen Sensoren [2]. Verglichen mit elektrischen Sensoren bringen faseroptische Messsysteme jedoch den großen technischen Aufwand der Wandlung von der optischen in die elektrische Domäne mit sich, zumal sich in der Regel die zusätzliche Aufgabe stellt, den Einfluss der nicht interessierenden Größe (Temperatur beziehungsweise Dehnung) in der Messung auszublenden. Die vorliegende Veröffentlichung stellt einen vereinfachten Aufbau vor, der Messungen mit Faser-Bragg-Gitter-Sensoren mit vergleichsweise geringem Aufwand ermöglicht und der zusätzlich die Möglichkeit bietet, temperatur- beziehungsweise dehnungskompensiert zu messen. Der Aufbau wurde sowohl simulativ als auch im Versuch überprüft.
Isolation and Diversity Analysis of Resistance Gene Homologues from Switchgrass
Authors: Zhu Qihui , Bennetzen Jeffrey L , Smith Shavannor M
Published: April 2013

Resistance gene homologs (RGHs) were isolated from the switchgrass variety Alamo by a combination of polymerase chain reaction and expressed sequence tag (EST) database mining. Fifty-eight RGHs were isolated by polymerase chain reaction and 295 RGHs were identified in 424,545 switchgrass ESTs. Four nucleotide binding site−leucine-rich repeat RGHs were selected to investigate RGH haplotypic diversity in seven switchgrass varieties chosen for their representation of a broad range of the switchgrass germplasm. Lowland and upland ecotypes were found to be less similar, even from nearby populations, than were more distant populations with similar growth environments. Most (83.5%) of the variability in these four RGHs was found to be attributable to the within-population component. The difference in nucleotide diversity between and within populations was observed to be small, whereas this diversity is maintained to similar degrees at both population and ecotype levels. The results also revealed that the analyzed RGHs were under positive selection in the studied switchgrass accessions. Intragenic recombination was detected in switchgrass RGHs, thereby demonstrating an active genetic process that has the potential to generate new resistance genes with new specificities that might act against newly-arising pathogen races.
Purifying Selection Causes Widespread Distortions of Genealogical Structure on the Human X Chromosome
Authors: O’Fallon Brendan
Published: April 2013

The extent to which selective forces shape patterns of genetic and genealogical variation is unknown in many species. Recent theoretical models have suggested that even relatively weak purifying selection may produce significant distortions in gene genealogies, but few studies have sought to quantify this effect in humans. Here, we employ a reconstruction method based on the ancestral recombination graph to infer genealogies across the length of the human X chromosome and to examine time to most recent common ancestor (TMRCA) and measures of tree imbalance at both broad and very fine scales. In agreement with theory, TMRCA is significantly reduced and genealogies are significantly more imbalanced in coding regions and introns when compared to intergenic regions, and these effects are increased in areas of greater evolutionary constraint. These distortions are present at multiple scales, and chromosomal regions as broad as 5 Mb show a significant negative correlation in TMRCA with exon density. We also show that areas of recent TMRCA are significantly associated with the disease-causing potential of site as measured by the MutationTaster prediction algorithm. Together, these findings suggest that purifying selection has significantly distorted human genealogical structure on both broad and fine scales and that few chromosomal regions escape selection-induced distortions.
Incidence of Rash After Amoxicillin Treatment in Children With Infectious Mononucleosis
Authors: Chovel-Sella Aluma , Ben Tov Amir , Lahav Einat , Mor Orna , Rudich Hagit , Paret Gideon , Reif Shimon
Published: April 2013

BACKGROUND:

“Ampicillin rash,” a phenomenon unique to patients with Epstein-Barr virus acute infectious mononucleosis (AIM) treated with ampicillin, was first reported in the 1960s. The incidence was estimated as being between 80% and 100%, and the figures have not been reviewed since those first accounts. We sought to establish the current incidence of rash associated with antibiotic treatment among children with AIM.

METHODS:

A retrospective study of all hospitalized children diagnosed as having AIM based upon positive Epstein-Barr virus serology in 2 pediatric tertiary medical centers in Israel.

RESULTS:

Of the 238 children who met the study entry criteria during the study period, 173 were treated with antibiotics. Fifty-seven (32.9%) of the subjects treated with antibiotics had a rash during their illness compared with 15 (23.1%) in untreated patients (P = .156; not significant). Amoxicillin was associated with the highest incidence of antibiotic-induced rash occurrence (29.5%, 95% confidence interval: 18.52–42.57), but significantly lower than the 90% rate reported for ampicillin in past studies. Age, gender, ethnicity, and atopic or allergic history were not associated with the development of rash after antibiotic exposure. Among the laboratory data, only increased white blood cell counts were more prevalent among subjects who did not develop an antibiotic-induced rash.

CONCLUSIONS:

The incidence of rash in pediatric patients with AIM after treatment with the current oral aminopenicillin (amoxicillin) is much lower than originally reported.
Association Between Total Duration of Breastfeeding and Iron Deficiency
Authors: Maguire Jonathon L. , Salehi Leila , Birken Catherine S. , Carsley Sarah , Mamdani Muhammad , Thorpe Kevin E. , Lebovic Gerald , Khovratovich Marina , Parkin Patricia C. ,   on behalf of the TARGet Kids! collaboration
Published: April 2013

OBJECTIVE:

To determine whether there is an association between the total breastfeeding duration and iron stores, iron deficiency, and iron deficiency anemia in healthy urban children.

METHODS:

A cross-sectional study of healthy children, aged 1 to 6 years, seen for primary health care between December 2008 and July 2011 was conducted through the TARGet Kids! practice-based research network. Univariate and adjusted regression analyses were used to evaluate an association between total breastfeeding duration and serum ferritin, iron deficiency, and iron deficiency anemia.

RESULTS:

Included were 1647 healthy children (median age 36 months) with survey, anthropometric, and laboratory data. An association was found between increasing duration of breastfeeding and lower serum ferritin (P = .0015). Adjusted logistic regression analysis revealed the odds of iron deficiency increased by 4.8% (95% confidence interval: 2%–8%) for each additional month of breastfeeding. Exploratory analysis suggested an increasing cumulative probability of iron deficiency with longer total breastfeeding duration with an adjusted odds ratio of 1.71 (95% confidence interval: 1.05–2.79) for iron deficiency in children breastfed over versus under 12 months of age. The relationship between total breastfeeding duration and iron deficiency anemia did not meet statistical significance.

CONCLUSIONS:

Increased total breastfeeding duration is associated with decreased iron stores, a clinically important association warranting additional investigation.
Reversible Lactic Acidosis in a Newborn With Thiamine Transporter-2 Deficiency
Authors: Pérez-Dueñas Belén , Serrano Mercedes , Rebollo Mónica , Muchart Jordi , Gargallo Eva , Dupuits Celine , Artuch Rafael
Published: April 2013

Thiamine transporter-2 deficiency is a recessive disease caused by mutations in the SLC19A3 gene. Patients manifest acute episodes of encephalopathy; symmetric lesions in the cortex, basal ganglia, thalami or periaqueductal gray matter, and a dramatic response to biotin or thiamine. We report a 30-day-old patient with mutations in the SLC19A3 gene who presented with acute encephalopathy and increased level of lactate in the blood (8.6 mmol/L) and cerebrospinal fluid (7.12 mmol/L), a high excretion of α-ketoglutarate in the urine, and increased concentrations of the branched-chain amino acids leucine and isoleucine in the plasma. MRI detected bilateral and symmetric cortico-subcortical lesions involving the perirolandic area, bilateral putamina, and medial thalami. Some lesions showed low apparent diffusion coefficient values suggesting an acute evolution; others had high values likely to be subacute or chronic, most likely related to the perinatal period. After treatment with thiamine and biotin, irritability and opisthotonus disappeared, and the patient recovered consciousness. Biochemical disturbances also disappeared within 48 hours. After discontinuing biotin, the patient remained stable for 6 months on thiamine supplementation (20 mg/kg/day). The examination revealed subtle signs of neurologic sequelae, and MRI showed necrotic changes and volume loss in some affected areas. Our observations suggest that patients with thiamine transporter 2 deficiency may be vulnerable to metabolic decompensation during the perinatal period, when energy demands are high. Thiamine defects should be excluded in newborns and infants with lactic acidosis because prognosis largely depends on the time from diagnosis to thiamine supplementation.
Effect of Slag on Mixing Time in Gas-Stirred Ladles Assisted with a Physical Model
Authors: Amaro-Villeda Adrián M. , Conejo A. , Ramírez-Argáez Marco A.
Published: April 2013

A 1/6th water physical model of a 140 tons gas-stirred steel ladle is used to evaluate mixing times (τm at 95% of chemical uniformity) in a two phase system without slag (air-water) and in a more realistic three phase system (air-water-oil) to simulate the argon-steel-slag system and quantify the effect of the slag layer on the mixing time. Slag layer is kept constant at 0.004 m. Mixing times are estimated through measured changes in pH due to the addition of a tracer (NaOH 1 M). The effect of the following variables on the mixing time is evaluated for a single injector: gas flow rate (7, 17 y 37 l/min) and the injector position (R/r= 0, 1/3, ½, 2/3 and 4/5). Experimental results obtained in this work show good agreement when compared against mixing time correlations reported by Mazumdar for the two phase air-water case (no slag considered). Another comparison is done using the new concept called “effective bath height” proposed by Barati, where the mixing time is a function of the size of the slag layer since this layer dissipates part of the total amount of stirring energy introduced into the ladle by the injection of gas. Agreement is not good in this case. Finally, an estimation of the percentage of the stirring energy dissipated by the slag is computed, including other factors that govern the dissipation of stirring energy. Percentage of energy dissipated by the slag is found to be between 2.7 to 12 % depending on the process conditions.
Decarburization of Hot-Rolled Non-Oriented Electrical Steels
Authors: Gutiérrez Emmanuel J. , Salinas Armando
Published: April 2013

The high temperature decarburization-oxidation behavior of hot rolled, non-oriented electrical steel strips is investigated during air-annealing treatments. Annealing temperature and time are varied from 700 – 1050 °C and 10 to 150 min, respectively. The experimental results show that uniform external oxidation affects strongly the rate at which carbon can be removed from this material. The thickness of the oxide layer formed after 150 minutes of annealing increases linearly with increasing temperature in the range 828 and 920 °C. The effect of temperature on the thickness of the oxide scale at temperatures outside this range is significantly smaller. These results indicate that the rate of oxidation in this material is strongly influenced by the microstructure of the steel during annealing. Decarburization rates are very slow during annealing at T ≤ 750 °C where the oxide layer is thin and porous. In contrast, fast and intense decarburization of the strips is observed as a result of annealing at temperatures between 800 and 850 °C. Finally, decarburization at T ≥ 875 °C becomes slower as the temperature is increased until at T ≥ 950 °C this process is practically inhibited. Measurements of C content as a function of time and temperature show that the observed decarburization kinetics follows Wagner’s model at 800 and 850 °C. However, at higher annealing temperatures decarburization is slower than that predicted by the model. This behavior is related to the increment of the oxide scale thickness and a transition from cracked to crack-free oxide structure which makes C diffusion through the oxide film very difficult.
Mid-infrared silicon waveguide resonators with Q∼105 by using photonic crystal cavities
Authors: Lin Pao , Singh Vivek , Cai Yan , Patel Neil Sunil , Mu Jianwei , Zhang Lin , Kimerling Lionel , Agarwal Anuradha Murthy
Published: April 2013

One dimensional photonic crystal 1D-PhC silicon waveguide resonators with quality factor, Q∼105, are demonstrated at mid-infrared wavelengths between 2 um to 5 um. Silicon has several advantages for mid-infrared applications including its broad mid-infrared transmission spectrum which extends out to 9 um, CMOS compatible fabrication processing, and ease of electronic-photonic integration. The proposed resonators are composed of photonic crystal cavities with optimized (i) lattice parameter a, (ii) cavity width w and (iii) hole radius r. Finite difference time domain (FDTD) simulations are used to adjust these three parameters, a, w, and r, to select a resonant frequency of interest within the mid-infrared spectral range. Due to the high quality factor Q, these PhC silicon waveguide resonators have much higher sensitivity as chemical sensors and have the potential to replace bulky instruments such as an FTIR.
Microstructure-based Simulations of the High-Strain-Rate Response of Heterogeneous Ti/Al/B Reactive Powder Mixtures
Authors: Gonzales Manny , Gurumurthy Ashok , Kennedy Gregory B. , Gokhale Arun M. , Thadhani Naresh N.
Published: April 2013

We investigate the dynamic behavior under uniaxial stress loading conditions of heterogeneous mixtures of Ti/Al/B via impact simulations on simulated microstructures. We simulate a range of Al concentrations at a constant theoretical material density (TMD) to determine their effects on the mechanical response of a realistic microstructure to impact conditions. We also study particle-level effects such as mixing, extreme deformation, and hot spot formation due to void collapse, as a function of microstructure. Our goal is to shed light on the possible meso-scale phenomena that makes a certain mixture more reactive than others of variable Al composition.
Difference in elastic properties of CrB2 determined by microscopic and macroscopic measurements
Authors: Tanaka Katsushi , Tsutsui Satoshi , Okamoto Norihiko L. , Inui Haruyuki , Baron Alfred Q.R.
Published: April 2013

CrB2 possess the hexagonal AlB2 structure which belongs to the spacegroup of P6/mmm. The compound exhibits para- to antiferro-magnetic transition at about 88 K. By using a macroscopic measurement technique, that is, a conventional resonant ultrasound spectroscopy (RUS) with a millimeter size mono-crystal, significant elastic anomalies have been observed just above the magnetic transition temperature. On the other hand, elastic constants determined by a microscopic measurement technique, that is, an inelastic X-ray scattering method (BL35XU of SPring-8, Japan) do not show any elastic anomalies at around the transition temperature. In order to explain the discrepancy, we have introduced a kind of so called ΔE effect resulting from a multidomain structure. If crystal lattice is slightly deformed by a spontaneous magnetostriction in the antiferromagnetic state, the symmetry of crystal lattice is lowered from hexagonal to monoclinic when the symmetry of magnetic structure is taken into account. By the lowering of the symmetry, the crystal consists of six magnetic domains in the antiferro magnetic state. If magnetic domain boundaries move in response to externally applied stresses, the mechanical deformation is absorbed by nonelastic deformations induced by the movement of magnetic domain boundaries. This multidomain model well explains the experimental results obtained by both microscopic (X-ray) and macroscopic (ultrasound) measurements. The microscopic measurement technique is useful to obtain the true elastic properties of crystal lattice without effects coming from a multidomain structure.
Influence of etching time and bonding strategies on the microshear bond strength of self- and light-cured pit-and-fissure sealants
Authors: Souza-Junior Eduardo José , Borges Boniek Castillo Dutra , Montes Marcos Antônio Japiassú Resende , Alonso Roberta Caroline Bruschi , Ambrosano Glaucia Maria Bovi , Sinhoreti Mário Alexandre Coelho
Published: April 2013

This study evaluated the impact of extended etching and bonding strategies on the microshear bond strength of three sealant materials. Two pit-and-fissure sealants [FluroShield, Dentsply (light-cured) and AlphaSeal, DFL (self-cured)] and one light-cured flowable composite resin (Permaflo, Ultradent) were evaluated according to different enamel etching times (15 s or 30 s) and bonding procedures (no adhesive application, application of primer/hydrophobic resin or hydrophobic resin only). Intact enamel blocks were obtained from bovine teeth and sealed via the tested protocols. After 24 h, the microshear bond strength test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were classified by stereomicroscopy. Data were submitted to a three-way ANOVA and to Tukey's test (α=0.05). There was no statistically significant difference (p>0.05) among the materials. Permaflo showed higher bond strength when etched for 30 s alone. Enamel overetching decreased the bond strength of the light-cured sealant. Primer/bond previous treatment improved bond performance for AlphaSeal. In conclusion, from the tested conditions, all sealant materials presented similar bond strength values in relation to bonding protocol and etching time. The flowable composite can be used as a pit-and-fissure sealant. The use of a three-step adhesive system was essential for the self-cured sealant application.