bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistance of single polyaniline fibers and their junctions measured by double-probe atomic force microscopy
Authors: Higuchi Rintaro , Shingaya Yoshitaka , Nakayama Tomonobu
Published: July 2016

Electrical properties of polyaniline (PANI) fibers are of our interest as a component of network materials. Using a multiple-probe atomic force microscope with tuning fork probes, we investigated the resistance of single PANI fibers and their cross-point junction where the fibers contact each other. The resistivity of single PANI fibers was measured to be on the order of 10 Ω cm, and the contact resistance between PANI fibers was on the order of GΩ. The resistances through single cross-point junctions between two PANI fibers were very much dependent on the experimental condition, that is, the cross-point junction is stabilized or destabilized by physically placing the probes onto the two fibers. This suggests the nanomechanical instability of the cross-point junctions and a possibility to construct strain-responsive PANI fiber networks.
Suscetibilidade de Merremia cissoides, Neotonia wightii e Stizolobium aterrimum aos herbicidas amicarbazine, imazapic e sulfentrazone
Authors: Campos Luiz Henrique Franco , Carvalho Saul Jorge Pinto de , Nicolai Marcelo , Christoffoleti Pedro Jacob
Published: July 2016

Três experimentos foram desenvolvidos com o objetivo de avaliar a suscetibilidade das plantas daninhas Merremia cissoides, Neonotonia wightii e Stizolobium aterrimum aos herbicidas amicarbazone, imazapic e sulfentrazone, por meio de curvas de dose-resposta. Os experimentos foram instalados em solo argiloso, onde foram aplicadas oito doses de cada herbicida, em pré-emergência. As doses utilizadas foram: 8D, 4D, 2D, D, 1/2D, 1/4D, 1/8D e testemunha sem aplicação; sendo D a dose recomendada de amicarbazone (1200 g ha-1), imazapic (147 g ha-1), ou sulfentrazone (800 g ha-1). Para as espécies M. cissoides e N. wightii, os três herbicidas testados demonstraram controle eficaz até os 60 dias, nas doses recomendadas. Para a espécie S. aterrimum, somente o herbicida amicarbazone foi eficaz, na dose recomendada. Os níveis de controle garantem estes três herbicidas como opções de controle em pré-emergência para as espécies M. cissoides e N. wightii e apenas o herbicida amicarbazone, como opção de controle da S. aterrimum.
Manejo de Sagittaria montevidensis resistente aos mecanismos de ação da ALS e do FSII com saflufenacil associado a diferentes adjuvantes
Authors: Moura Diogo Da Silva , Noldin José Alberto , Galon Leandro , Schreiber Fábio , Martini Alfran Tellechea
Published: July 2016

Objetivou-se com esse trabalho avaliar o efeito de doses de saflufenacil e de adjuvantes no controle de sagitária resistente aos herbicidas inibidores de ALS e do Fotossistema II (FS II), e a fitotoxicidade a cultivar de arroz Epagri 108. Foram utilizados os biótipos de sagitária (Sagittaria montevidensis), SAGMO 10 - com resistência cruzada a herbicidas inibidores da ALS, e SAGMO 32 - com resistência múltipla a herbicidas inibidores da ALS e do FS II. Os tratamentos constituíram-se da aplicação de doses de saflufenacil: 75; 112,5 e 150 g i.a. ha-1; da adição dos adjuvantes Dash HC® (0,5% v/v); Assist® (1% v/v); Iharaguen-S® (0,5% v/v) e Veget’Oil® (1 L ha-1) para cada dose do herbicida aplicado nos biótipos de sagitária. Avaliou-se o controle da sagitária, a fitotoxicidade e a massa seca da parte aérea (MSPA) do arroz. O saflufenacil, nas doses de 75 a 150 g i.a. ha-1 não proporcionou controle eficiente dos biótipos de sagitária. A adição dos adjuvantes Veget’Oil®, Assist® e Iharaguen-S® ao saflufenacil não alterou a eficiência de controle de sagitária resistente a herbicidas. A cultivar Epagri 108 apresenta tolerância ao saflufenacil até 150 g i.a. ha-1, não ocorrendo redução da MSPA. A fitotoxicidade ocasionada às plantas de arroz pelo saflufenacil é menor ao se adicionar o Veget’Oil®. A massa seca das plantas do arrroz não foi afetada independente do adjuvante utilizado. O saflufenacil pode ser usado, até a dose de 150 g i.a. ha-1, associado ao adjuvante Veget’Oil® para o manejo de sagitária infestante do arroz cultivar Epagri 108, porém não proporciona controle adequado dos biótipos SAGMO 10 e SAGMO 32.
Atividade fotossintética de plantas cultivadas em solo contaminado com sulfentrazone
Authors: Belo Alessandra Ferreira , Ferreira Lino Roberto , Ferreira Evander Alves , Aguiar Luciana Monteiro , Santos José Barbosa dos , Cecon Paulo Roberto
Published: July 2016

Objetivou-se com este trabalho, avaliar os efeitos do sulfentrazone sobre as características associadas à atividade fotossintética de Helianthus annus, Canavalia ensiformis, Dolichos lab lab e Arachis hypogaea consideradas espécies com potencial de remediação de solo contaminado por esse herbicida. O experimento foi conduzido em esquema fatorial 4 x 3 em delineamento inteiramente casualizado, com quatro repetições. O primeiro fator constou do cultivo das espécies H. annus, C. ensiformis, D. lab lab e A. hypogaea e o segundo de três doses (0, 250 e 500 g ha-1) de sulfentrazone aplicadas em pré-emergência. Após o preenchimento dos vasos com 6,0 kg de solo, classificado como Argissolo Vermelho-Amarelo, fez-se a irrigação e aplicou-se à superfície do solo o herbicida. Um dia após esta aplicação, procedeu-se a semeadura das espécies vegetais. Aos 40 dias após a emergência (DAE) das espécies vegetais, foram determinadas a condutância estomática (gs - mol m-1 s-1), a taxa de transpiração (E - mol H2O m-2 s-1), a concentração de CO2 na câmara subestomática (Ci - µmol mol-1), o gradiente de CO2 (ΔC - µmol mol-1) e a taxa fotossintética (A - µmol m-2 s-1). Essas avaliações foram realizadas utilizando-se um analisador de gases no infravermelho (IRGA). Aos 100 DAE das plantas foi coletada a parte aérea e determinada a matéria seca. Resíduos de sulfentrazone no solo podem afetar as variáveis fisiológicas estudadas, todavia, a produção de matéria seca da parte aérea dessas espécies não foi influenciada pela ação do herbicida, independentemente das doses aplicadas, indicando a tolerância das espécies ao sulfentrazone.
Controle de capim-amargoso perenizado em pleno florescimento
Authors: Zobiole Luiz Henrique Saes , Krenchinski Fábio Henrique , Albrecht Alfredo Junior Paiola , Pereira Gabriel , Lucio Felipe Rodolfo , Rossi Caio , Rubin Rogério Da Silva
Published: July 2016

O capim-amargoso é uma planta de difícil controle devido as suas características vegetativas de sobrevivência e pela sua resistência ao glyphosate. O objetivo do presente trabalho foi avaliar a eficácia de diversos graminicidas no controle do capim-amargoso perenizado em pleno florescimento. Para isso foram instalados dois experimentos a campo, sendo que no experimento 1 foram testados 4 graminicidas associados ao glyphosate, em aplicação única no qual foi avaliado as porcentagens de controle aos 14 e 28 dias após a aplicação (DAA). Já no experimento 2 foram aplicados 17 tratamentos (aplicação A) e após 35 dias realizada a aplicação sequencial de clethodim + glyphosate (Aplicação B), nesse experimento foram avaliadas as porcentagens de controle aos 14, 28 e 35 DAA de A e B, assim como a massa seca das plantas de capim-amargoso após a última avaliação de controle. No experimento 1 não se obteve controle satisfatório das plantas de capim-amargoso perenizado com nenhum dos tratamentos utilizados. No experimento 2, os resultados antes da aplicação sequencial (B) não foram eficientes no controle do capim-amargoso, entretanto aos 35 dias após aplicação B, os tratamentos com as doses de haloxyfop-methyl a partir de 100 g i.a. ha-1 associado ao herbicida clethodim + glyphosate (Aplicação B) foram eficientes no seu controle com consequente diminuição da massa seca. Conclui-se que a aplicação única de graminicidas não foi eficaz no controle do capim-amargoso em pleno florescimento, sendo necessário a aplicação sequencial (A + B) para promover o controle adequado.
Role of the 3‐Vessel and Trachea View in Antenatal Detection of Tetralogy of Fallot
Authors: Palatnik Anna , Grobman William A. , Cohen Leeber S. , Dungan Jeffrey S. , Gotteiner Nina L.
Published: July 2016

Prenatal diagnosis of tetralogy of Fallot remains less frequent compared to other major congenital heart defects. In this study, we examined how often the 3‐vessel and trachea view was abnormal in a large series of prenatally diagnosed cases of tetralogy of Fallot. In addition, we compared its sensitivity to that of the traditional outflow tract views for detection of tetralogy of Fallot. We found that both views were abnormal in all fetuses with tetralogy of Fallot, showing reversed aortic‐to‐pulmonary valve and aortic arch isthmus‐to‐ductus arteriosus ratios in the outflow tract and 3‐vessel and trachea views, respectively. However, as a single measured marker, the enlarged aortic arch isthmus on the 3‐vessel and trachea view appears to be the most sensitive for tetralogy of Fallot.
Description and Comparison of the Sonographic Characteristics of Poorly Differentiated Thyroid Carcinoma and Anaplastic Thyroid Carcinoma
Authors: Hahn Soo Yeon , Shin Jung Hee
Published: July 2016

Objectives

Although poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma account for a substantial portion of the morbidity and mortality associated with thyroid cancer, a chance of a cure exists with aggressive treatment, especially in patients with poorly differentiated thyroid carcinoma. The goal of this study was to evaluate the sonographic characteristics of poorly differentiated thyroid carcinoma and to compare the sonographic findings of poorly differentiated and anaplastic thyroid carcinomas.

Methods

The study included 29 patients with 30 poorly differentiated thyroid carcinomas and 26 patients with 26 anaplastic thyroid carcinomas. Two radiologists retrospectively reviewed sonographic findings. Clinical and sonographic findings were compared between poorly differentiated and anaplastic thyroid carcinomas by univariate and multivariate analyses.

Results

In the group of patients with poorly differentiated thyroid carcinoma, the mean age was 53.7 years (range, 14–73 years), and the mean tumor size was 3.6 cm (range, 0.6–10.0 cm). The common sonographic findings of poorly differentiated thyroid carcinoma were heterogeneous echogenicity (93.3%), solitary nodules (80.0%), a circumscribed margin (63.3%), an oval‐to‐round shape (63.3%), and hypoechogenicity (60.0%). A circumscribed margin (P = .003) and an oval‐to‐round shape (P = .015) were significantly more frequent in poorly differentiated thyroid carcinoma than in anaplastic thyroid carcinoma. In the multivariate analysis, only the circumscribed margin on sonography was an independent predicting factor for poorly differentiated thyroid carcinoma (odds ratio, 4.642).

Conclusions

Both poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma commonly present as a relatively large malignant mass on sonography; however, poorly differentiated thyroid carcinoma showed a significantly higher incidence of a circumscribed margin and an oval‐to‐round shape than anaplastic thyroid carcinoma. Knowledge of sonographic characteristics will be useful for differentiation of poorly differentiated and anaplastic thyroid carcinomas.
QUALIDADE DA ÁGUA UTILIZADA NA IRRIGAÇÃO DE HORTALIÇAS NA REGIÃO DO LITORAL NORTE DE SANTA CATARINA
Authors: Cantu Rafael Ricardo , Haro Marcelo Mendes , Morales Rafael Gustavo Ferreira , Visconti Alexandre , Schallenberger Euclides
Published: July 2016

A produção de hortaliças é uma atividade com elevada importância socioeconômica para o Estado de Santa Catarina. Sua viabilidade técnica e econômica depende da disponibilidade da água utilizada para irrigação, cuja qualidade deve atender aos requisitos legais. O presente trabalho teve como objetivo avaliar atributos relacionados à qualidade da água empregada na irrigação de hortaliças, oriunda de reservatórios de captação de água das chuvas e de rios, açudes, poços e córregos na região do litoral Norte de Santa Catarina. Os municípios do estudo foram Tijucas, Itajaí, Itapema, Piçarras, Barra Velha, Porto Belo e Camboriú. Foram analisadas características físicas (dureza, condutividade elétrica e sólidos dissolvidos totais), químicas (pH, Ca, Mg, Na, K, Cd, Pb) e biológicas (coliformes termotolerantes e demanda bioquímica de oxigênio) das amostras de água. Os resultados revelaram que, apesar de possuir algumas inconformidades, as águas da chuva e de poços artesianos são as mais indicadas para a irrigação do cultivo de hortaliças no litoral Norte Catarinense.
SÍNTESE DE BIODIESEL A PARTIR DE RESÍDUOS GORDUROSOS DE FRITURA UTILIZANDO COMO FERRAMENTA PLANEJAMENTO FATORIAL
Authors: Tintor Cleiton Barcot , Hirata Daniela Battaglia , Pereira Ernandes Benedito
Published: July 2016

O objetivo deste trabalho foi a produção de biodiesel via rota enzimática, utilizando resíduo gorduroso de fritura como substrato e o planejamento fatorial como ferramenta de análise. O planejamento fatorial foi empregado para avaliar os parâmetros da reação de transesterificação, quanto à razão molar óleo:etanol (1:3; 1:4,7; 1:9; 1:13,3 e 1:15) e temperatura (30, 34, 45, 56 e 60ºC). A reação foi conduzida em shaker, usando 20 g do meio reaciona e 2 g do derivado imobilizado de lipase durante 15h. Os diferentes ensaios foram avaliados por cromatografia gasosa (verificação do teor de ésteres de etila) e viscosímetro, mostrando uma produção de 67,9% de ésteres de etila para a razão molar óleo:etanol de 1:4,7 e 34ºC de temperatura; e uma viscosidade de 3,82 cP para a razão molar óleo:etanol de 1:3 e 45ºC de temperatura, sendo estes os melhores resultados, indicando que a variável que interferiu significativamente no rendimento da reação foi a temperatura.
Generating human hematopoietic stem cells in vitro –exploring endothelial to hematopoietic transition as a portal for stemness acquisition
Authors: Slukvin Igor I.
Published: July 2016

Advances in cellular reprogramming technologies have created alternative platforms for the production of blood cells, either through inducing pluripotency in somatic cells or by way of direct conversion of nonhematopoietic cells into blood cells. However, de novo generation of hematopoietic stem cells (HSCs) with robust and sustained multilineage engraftment potential remains a significant challenge. Hemogenic endothelium (HE) has been recognized as a unique transitional stage of blood development from mesoderm at which HSCs arise in certain embryonic locations. The major aim of this review is to summarize historical perspectives and recent advances in the investigation of endothelial to hematopoietic transition (EHT) and HSC formation in the context of aiding in vitro approaches to instruct HSC fate from human pluripotent stem cells. In addition, direct conversion of somatic cells to blood and HSCs and progression of this conversion through HE stage are discussed. A thorough understanding of the intrinsic and microenvironmental regulators of EHT that lead to the acquisition of self‐renewal potential by emerging blood cells is essential to advance the technologies for HSC production and expansion.
An improved empirical model of electron and ion fluxes at geosynchronous orbit based on upstream solar wind conditions
Authors: Denton M. H. , Henderson M. G. , Jordanova V. K. , Thomsen M. F. , Borovsky J. E. , Woodroffe J. , Hartley D. P. , Pitchford D.
Published: July 2016

A new empirical model of the electron fluxes and ion fluxes at geosynchronous orbit (GEO) is introduced, based on observations by Los Alamos National Laboratory (LANL) satellites. The model provides flux predictions in the energy range ~1 eV to ~40 keV, as a function of local time, energy, and the strength of the solar wind electric field (the negative product of the solar wind speed and the z component of the magnetic field). Given appropriate upstream solar wind measurements, the model provides a forecast of the fluxes at GEO with a ~1 h lead time. Model predictions are tested against in‐sample observations from LANL satellites and also against out‐of‐sample observations from the Compact Environmental Anomaly Sensor II detector on the AMC‐12 satellite. The model does not reproduce all structure seen in the observations. However, for the intervals studied here (quiet and storm times) the normalized root‐mean‐square deviation < ~0.3. It is intended that the model will improve forecasting of the spacecraft environment at GEO and also provide improved boundary/input conditions for physical models of the magnetosphere.
Pilot Mouse Study of 1 mm Inner Diameter (ID) Vascular Graft Using Electrospun Poly(ester urea) Nanofibers
Authors: Gao Yaohua , Yi Tai , Shinoka Toshiharu , Lee Yong Ung , Reneker Darrell H. , Breuer Christopher K. , Becker Matthew L.
Published: July 2016

An off‐the‐shelf, small diameter tissue engineered vascular graft (TEVG) would be transformative to surgeons in multiple subspecialties. Herein, the results of a small diameter (ID ≈ 1 mm) vascular graft constructed from resorbable, amino acid‐based poly(ester urea) (PEU) are reported. Electrospun PEU grafts of two different wall thicknesses (type A: 250 μm; type B: 350 μm) are implanted as abdominal infra‐renal aortic grafts in a severe combined immune deficient/beige mouse model and evaluated for vessel remodeling over one year. Significantly, the small diameter TEVG does not rupture or lead to acute thrombogenic events during the intervals tested. The pilot TEVG in vivo shows long‐term patency and extensive tissue remodeling with type A grafts. Extensive tissue remodeling in type A grafts leads to the development of well‐circumscribed neovessels with an endothelial inner lining, a neointima containing smooth muscle cells. However, due to slow degradation of the PEU scaffold materials in vivo, the grafts remain after one year. The type B grafts, which have 350 μm thick walls, experience occlusion over the one year interval due to intimal hyperplasia. This study affords significant findings that will guide the design of future generations of small diameter vascular grafts.
Synthesis of 3‐Iodoquinolines by Copper‐Catalyzed Tandem Annulation from Diaryliodoniums, Nitriles, and 1‐Iodoalkynes
Authors: Wang Xuesong , Wang Xingyong , Huang Dayun , Liu Chulong , Wang Xinyan , Hu Yuefei
Published: July 2016

A novel method for the synthesis of 3‐iodoquinolines was developed by copper‐catalyzed tandem annulation from diaryliodoniums, nitriles, and 1‐iodoalkynes. It is a method that is characterized by the most convenient operation and wide molecular diversity.

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Investigation into Morphology Characterization of Various Surface Electrode of Biopolymer Actuator: Ionic Polymer Metal Composites
Authors: Sun Zhuangzhi , Zhao Gang , Yang Ge
Published: July 2016

Focusing on various surface electrode effects on electromechanical properties of biopolymer actuator: ionic polymer metal composites (IPMC), a new laminated structure model, composed with the electrolyte layer, the middle layer and the surface electrode layer, is provided to redefine the composition of IPMC actuator. A failure analysis is performed to study the failure reasons of IPMC actuator. Subsequently, based on various surface electrode of IPMC actuator, the electromechanical properties were further investigated by comparison with the chemical plating samples and the electrophoretic deposition sample. Finally, after the analysis of the morphology characteristics, the improvement mechanism of the various surface electrodes is obtained to further clarify. Results find the electromechanical properties of IPMC actuator is closely attributed to the electrical conductivity of the surface electrode.
Inverted Current–Voltage Hysteresis in Mixed Perovskite Solar Cells: Polarization, Energy Barriers, and Defect Recombination
Authors: Tress Wolfgang , Correa Baena Juan Pablo , Saliba Michael , Abate Antonio , Graetzel Michael
Published: July 2016

Organic‐inorganic metal halide perovskite solar cells show hysteresis in their current–voltage curve measured at a certain voltage sweep rate. Coinciding with a slow transient current response, the hysteresis is attributed to a slow voltage‐driven (ionic) charge redistribution in the perovskite solar cell. Thus, the electric field profile and in turn the electron/hole collection efficiency become dependent on the biasing history. Commonly, a positive prebias is beneficial for a high power‐conversion efficiency. Fill factor and open‐circuit voltage increase because the prebias removes the driving force for charge to pile‐up at the electrodes, which screen the electric field. Here, it is shown that the piled‐up charge can also be beneficial. It increases the probability for electron extraction in case of extraction barriers due to an enhanced electric field allowing for tunneling or dipole formation at the perovskite/electrode interface. In that case, an inverted hysteresis is observed, resulting in higher performance metrics for a voltage sweep starting at low prebias. This inverted hysteresis is particularly pronounced in mixed‐cation mixed‐halide systems which comprise a new generation of perovskite solar cells that makes it possible to reach power‐conversion efficiencies beyond 20%.
Parallelized Nanopillar Perovskites for Semitransparent Solar Cells Using an Anodized Aluminum Oxide Scaffold
Authors: Kwon Hyeok‐Chan , Kim Areum , Lee Hongseuk , Lee Daehee , Jeong Sunho , Moon Jooho
Published: July 2016

Semitransparent solar cells have attracted significant attention for practical applications, such as windows in buildings and automobiles. Here, semitransparent, highly efficient, 1D nanostructured perovskite solar cells are demonstrated employing anodized aluminum oxide (AAO) as a scaffold layer. The parallel nanopillars in the perovskite layer enable construction of haze‐free semitransparent devices without any hysteresis behavior. By controlling the pore size in the AAO, the volume occupied by the perovskite layer can be precisely varied, and the color neutrality of the resulting devices can be achieved. With the incorporation of a transparent cathodic electrode (indium tin oxide) with a buffer layer (MoOx), a highly efficient semitransparent nanopillared perovskite solar cell is achievable with a power‐conversion efficiency of 9.6% (7.5%) and a whole device average visible light transmittance of 33.4% (41.7%). To determine the role of the scaffold layer in improving the photoelectrical properties of the cell, impedance spectroscopy analyses are performed, revealing that the AAO‐structured perovskite layer suppresses internal ion diffusion and enables critical improvements in long‐term stability under continuous illumination.
Paternity in wild ring‐tailed lemurs (Lemur catta): Implications for male mating strategies
Authors: Parga Joyce A. , Sauther Michelle L. , Cuozzo Frank P. , Youssouf Jacky Ibrahim Antho , Lawler Richard R. , Sussman Robert W. , Gould Lisa , Pastorini Jennifer
Published: July 2016

In group‐living species with male dominance hierarchies where receptive periods of females do not overlap, high male reproductive skew would be predicted. However, the existence of female multiple mating and alternative male mating strategies can call into question single‐male monopolization of paternity in groups. Ring‐tailed lemurs (Lemur catta) are seasonally breeding primates that live in multi‐male, multi‐female groups. Although established groups show male dominance hierarchies, male dominance relationships can break down during mating periods. In addition, females are the dominant sex and mate with multiple males during estrus, including group residents, and extra‐group males—posing the question of whether there is high or low male paternity skew in groups. In this study, we analyzed paternity in a population of wild L. catta from the Bezà Mahafaly Special Reserve in southwestern Madagascar. Paternity was determined with 80–95% confidence for 39 offspring born to nine different groups. We calculated male reproductive skew indices for six groups, and our results showed a range of values corresponding to both high and low reproductive skew. Between 21% and 33% of offspring (3 of 14 or three of nine, counting paternity assignments at the 80% or 95% confidence levels, respectively) were sired by extra‐troop males. Males siring offspring within the same group during the same year appear to be unrelated. Our study provides evidence of varying male reproductive skew in different L. catta groups. A single male may monopolize paternity across one or more years, while in other groups, >1 male can sire offspring within the same group, even within a single year. Extra‐group mating is a viable strategy that can result in extra‐group paternity for L. catta males.
Zugang zu Pyrazolidin‐3,5‐dionen durch anodischen N‐N‐Bindungsaufbau
Authors: Gieshoff Tile , Schollmeyer Dieter , Waldvogel Siegfried R.
Published: July 2016

Pyrazolidin‐3,5‐dione sind wichtige heterocyclische Strukturmotive und von großem Interesse für pharmazeutische Anwendungen. In der klassischen organischen Chemie wird die Hydrazinbindung durch eine Kondensationsreaktion des entsprechenden Hydrazins eingebracht. Allerdings sind N,N′‐Diarylhydrazine toxisch und müssen wegen ihrer geringen kommerziellen Verfügbarkeit separat hergestellt werden. Wir haben einen alternativen und nachhaltigen Zugang zu Pyrazolidin‐3,5‐dionen unter Verwendung leicht zugänglicher Aniline als Vorstufen entwickelt. Der N‐N‐Bindungsaufbau erfolgt durch eine anodische Oxidation, die in einer sehr einfachen ungeteilten Zelle unter galvanostatischen Bedingungen durchgeführt wird.
Die Chemie von [AuO]+/CH4 in der Gasphase: Selektive Sauerstoffatom‐Übertragung auf, statt Wasserstoffatom‐Abstraktion von Methan
Authors: Zhou Shaodong , Li Jilai , Schlangen Maria , Schwarz Helmut
Published: July 2016

Die thermischen Reaktionen von [AuO]+ mit Methan wurden mittels FT‐ICR‐Massenspektrometrie und quantenchemischen Rechnungen untersucht. Im Gegensatz zu den bereits untersuchten Oxiden der 11. Gruppe, [CuO]+ und [AgO]+, reagiert [AuO]+ mit CH4 ausschließlich unter Bildung von CH3OH durch Sauerstoffatomübertragung. Der neuartige Mechanismus dieser spezifischen Oxidation wird vorgestellt und die Ursachen der Trägheit des [AgO]+/CH4‐Reaktionspaares mittels theoretischer Untersuchungen aufgedeckt.
Sequence‐Specific Incorporation of Enzyme–Nucleotide Chimera by DNA Polymerases
Authors: Welter Moritz , Verga Daniela , Marx Andreas
Published: July 2016

DNA polymerases select the right nucleotide for the growing polynucleotide chain based on the shape and geometry of the nascent nucleotide pairs and thereby ensure high DNA replication selectivity. High‐fidelity DNA polymerases are believed to possess tight active sites that allow little deviation from the canonical structures. However, DNA polymerases are known to use nucleotides with small modifications as substrates, which is key for numerous core biotechnology applications. We show that even high‐fidelity DNA polymerases are capable of efficiently using nucleotide chimera modified with a large protein like horseradish peroxidase as substrates for template‐dependent DNA synthesis, despite this “cargo” being more than 100‐fold larger than the natural substrates. We exploited this capability for the development of systems that enable naked‐eye detection of DNA and RNA at single nucleotide resolution.
The Unique Gas‐Phase Chemistry of the [AuO]+/CH4 Couple: Selective Oxygen‐Atom Transfer to, Rather than Hydrogen‐Atom Abstraction from, Methane
Authors: Zhou Shaodong , Li Jilai , Schlangen Maria , Schwarz Helmut
Published: July 2016

The thermal reaction of [AuO]+ with methane has been explored using FT‐ICR mass spectrometry complemented by high‐level quantum chemical calculations. In contrast to the previously studied congener [CuO]+, and to [AgO]+, [AuO]+ reacts with CH4 exclusively via oxygen‐atom transfer to form CH3OH, and a novel mechanistic scenario for this selective oxidation process has been revealed. Also, the origin of the inertness of the [AgO]+/CH4 couple has been addressed computationally.
Control of Imine Exchange Kinetics with Photoswitches to Modulate Self‐Healing in Polysiloxane Networks by Light Illumination
Authors: Kathan Michael , Kovaříček Petr , Jurissek Christoph , Senf Antti , Dallmann Andre , Thünemann Andreas F. , Hecht Stefan
Published: July 2016

Various aldehyde‐containing photoswitches have been developed whose reactivity toward amines can be controlled externally. A thermally stable bifunctional diarylethene, which in its ring‐closed form exhibits imine formation accelerated by one order of magnitude, was used as a photoswitchable crosslinker and mixed with a commercially available amino‐functionalized polysiloxane to yield a rubbery material with viscoelastic and self‐healing properties that can be reversibly tuned by irradiation.
Dissipative particle dynamics studies on the interfacial tension of A/B homopolymer blends and the effect of Janus nanorods
Authors: Zhou Chun , Luo Shi‐kai , Sun Yi , Zhou Yang , Qian Wen
Published: July 2016

Janus nanorods are used as a novel rigid compatibilizer to improve the interfacial tension of incompatible A/B homopolymer blends. Dissipative particle dynamics (DPD) methods are preformed to explore the effect of Janus nanorods on the interfacial tension. The results show that Janus nanorods are a good compatibilizer only when the appropriate length is chosen, which is different from the traditional coil compatibilizer (surfactants and block copolymers). The length of the Janus nanorods can significantly influence their orientation through the competition between the entropic and enthalpic effects. The shorter Janus nanorods preferring “standing” have a better efficiency in improving the interfacial tension than the longer ones preferring “lying.” If we can control the orientation of the longer Janus nanorods, they are still a good compatibilizer. This simulation work can widen the application of Janus nanoparticles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44098.
Amphiphilic copolymers based on PEG‐acrylate as surface active water viscosifiers: Towards new potential systems for enhanced oil recovery
Authors: Raffa Patrizio , Broekhuis Antonius A. , Picchioni Francesco
Published: July 2016

With the purpose of investigating new potential candidates for enhanced oil recovery (EOR), amphiphilic copolymers based on Poly(ethylene glycol) methyl ether acrylate (PEGA) have been prepared by Atom Transfer Radical Polymerization (ATRP). A P(PEGA) homopolymer, a block copolymer with styrene PS‐b‐P(PEGA), and an analogous terpolymer including also sodium methacrylate (MANa) in the poly(PEGA) (PPEGA) block, PS‐b‐P(PEGA‐co‐MANa) have been prepared and characterized. Viscosity and surface activity of solutions of the prepared polymers in pure and salty water have been measured and the results have been interpreted in terms of the chemical structures of the systems. A clear influence of the presence of the charged MANa moieties has been observed in both rheological and interfacial properties. The PS‐b‐P(PEGA‐co‐MANa) terpolymer, being an effective surface active viscosifying agent, is a good candidate as polymeric surfactant for applications in enhanced oil recovery and related. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44100.
Establishment of X chromosome inactivation and epigenomic features of the inactive X depend on cellular contexts
Authors: Vallot Céline , Ouimette Jean‐François , Rougeulle Claire
Published: July 2016

X chromosome inactivation (XCI) is an essential epigenetic process that ensures X‐linked gene dosage equilibrium between sexes in mammals. XCI is dynamically regulated during development in a manner that is intimately linked to differentiation. Numerous studies, which we review here, have explored the dynamics of X inactivation and reactivation in the context of development, differentiation and diseases, and the phenotypic and molecular link between the inactive status, and the cellular context. Here, we also assess whether XCI is a uniform mechanism in mammals by analyzing epigenetic signatures of the inactive X (Xi) in different species and cellular contexts. It appears that the timing of XCI and the epigenetic signature of the inactive X greatly vary between species. Surprisingly, even within a given species, various Xi configurations are found across cellular states. We discuss possible mechanisms underlying these variations, and how they might influence the fate of the Xi.
Divergent Synthesis of Diastereomeric Sphingosines from a Chiral Aziridine
Authors: Kang On‐Yu , Shin Mi‐Ri , Kang Han‐Young
Published: July 2016

All four stereoisomers of sphingosines were synthesized starting from a single intermediate, chiral aziridine (2), which was efficiently prepared by enzymatic desymmetrization in an enatiopure form. Aziridine (2) was converted to 3, which was used for the synthesis of 4. Both the advanced key intermediates, vinylaziridines 3 and 4, were successfully converted to threo‐sphingosines 1a and 1b, respectively. Ring‐closing metathesis (RCM) using the Grubbs II catalyst was the key reaction in the synthesis. Two erythro‐sphingosines 1c and 1d were synthesized by the ring‐expansion reactions of vinylaziridines 3 and 4, followed by RCM reactions. The successful divergent synthesis confirmed that chiral vinylaziridine 2 can be used as a key intermediate for the synthesis of sphingosine‐related natural products.
Life‐cycle and cost of goods assessment of fed‐batch and perfusion‐based manufacturing processes for mAbs
Authors: Bunnak Phumthep , Allmendinger Richard , Ramasamy Sri V. , Lettieri Paola , Titchener‐Hooker Nigel J.
Published: July 2016

Life‐cycle assessment (LCA) is an environmental assessment tool that quantifies the environmental impact associated with a product or a process (e.g., water consumption, energy requirements, and solid waste generation). While LCA is a standard approach in many commercial industries, its application has not been exploited widely in the bioprocessing sector. To contribute toward the design of more cost‐efficient, robust and environmentally‐friendly manufacturing process for monoclonal antibodies (mAbs), a framework consisting of an LCA and economic analysis combined with a sensitivity analysis of manufacturing process parameters and a production scale‐up study is presented. The efficiency of the framework is demonstrated using a comparative study of the two most commonly used upstream configurations for mAb manufacture, namely fed‐batch (FB) and perfusion‐based processes. Results obtained by the framework are presented using a range of visualization tools, and indicate that a standard perfusion process (with a pooling duration of 4 days) has similar cost of goods than a FB process but a larger environmental footprint because it consumed 35% more water, demanded 17% more energy, and emitted 17% more CO2 than the FB process. Water consumption was the most important impact category, especially when scaling‐up the processes, as energy was required to produce process water and water‐for‐injection, while CO2 was emitted from energy generation. The sensitivity analysis revealed that the perfusion process can be made more environmentally‐friendly than the FB process if the pooling duration is extended to 8 days. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1324–1335, 2016
The role of more than 40 years of improvement in protein A chromatography in the growth of the therapeutic antibody industry
Authors: Bolton Glen R. , Mehta Krunal K.
Published: July 2016

Protein A chromatography has been used as the mAb capture step in the majority of FDA submissions. In this study, the performance of protein A chromatography, as indicated by capacity, operational flow rate, and productivity (rate of mAb production per liter of resin) was examined over its full history to gain insights into the reasons for its consistent use. Protein A productivity and capacity have increased 4.3 and 5.5% a year, respectively, since 1978. In contrast, protein A operational flow rate increased between 1978 and 2001 and then remained constant or declined as further improvements provided only marginal benefits. The productivity of protein A resin and also the mAb bioreactor titer (14% growth) rapidly improved starting in about 1990 to economically provide material for clinical trials. Technology improvement is typically driven by product sales. The sales of protein A resin, as indicated by sales of protein A ligand (21% growth), have closely paralleled the sales of mAbs (20% growth). Both increased rapidly in 2000 after the first major mAb therapeutics were approved and the markets were developed. It is likely that alternatives to protein A chromatography have not been implemented because of the order of magnitude improvement in protein A performance. Protein A membrane adsorbers and monoliths have higher productivity than packed columns due to their short bed heights and high operational flow rates. These devices are not currently practical for large‐scale manufacturing but may represent a format for future improvements in protein A productivity. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1193–1202, 2016
Comparative Analysis of DNA‐Binding Selectivity of Hairpin and Cyclic Pyrrole‐Imidazole Polyamides Based on Next‐Generation Sequencing
Authors: Kashiwazaki Gengo , Chandran Anandhakumar , Asamitsu Sefan , Kawase Takashi , Kawamoto Yusuke , Sawatani Yoshito , Hashiya Kaori , Bando Toshikazu , Sugiyama Hiroshi
Published: July 2016

Many long pyrrole‐imidazole polyamides (PIPs) have been synthesized in the search for higher specificity, with the aim of realizing the great potential of such compounds in biological and clinical areas. Among several types of PIPs, we designed and synthesized hairpin and cyclic PIPs targeting identical sequences. Bind‐n‐Seq analysis revealed that both bound to the intended sequences. However, adenines in the data analyzed by the previously reported Bind‐n‐Seq method appeared to be significantly higher in the motif ratio than thymines, even though the PIPs were not expected to distinguish A from T. We therefore examined the experimental protocol and analysis pipeline in detail and developed a new method based on Bind‐n‐Seq motif identification with a reference sequence (Bind‐n‐Seq‐MR). High‐throughput sequence analysis of the PIP‐enriched DNA data by Bind‐n‐Seq‐MR presented A and T comparably. Surface plasmon resonance assays were performed to validate the new method.
A Reusable Mesoporous Nickel Nanocomposite Catalyst for the Selective Hydrogenation of Nitroarenes in the Presence of Sensitive Functional Groups
Authors: Hahn Gabriela , Ewert Julia‐Katharina , Denner Christine , Tilgner Dominic , Kempe Rhett
Published: July 2016

The synthesis of aromatic amines from nitroarenes through hydrogenation is an industrially and academically important reaction. In addition, the employment of base metal catalysts in reactions that are preferentially mediated by rare noble metals is a desirable aim in catalysis and an attractive element‐conservation strategy. Especially appealing is the observation of novel selectivity patterns with such inexpensive metal catalysts. Herein, we report a novel mesostructured Ni nanocomposite catalyst. It is the first example of a reusable Ni catalyst that is able to hydrogenate nitroarenes selectively to anilines in the presence of highly sensitive functional groups such as C=C bonds and nitrile, aldehyde, and iodo substituents.
Palladium Nanoparticle Size Effect in Hydrodesulfurization of 4,6‐Dimethyldibenzothiophene (4,6‐DMDBT)
Authors: Shen Jing , Semagina Natalia
Published: July 2016

Pd nanoparticle size sensitivity of 4,6‐dimethyldibenzothiophene (4,6‐DMDBT) hydrodesulfurization was investigated by using 4, 8, 13, and 87 nm particles and was compared with the sulfur‐free and sulfur‐inhibited hydrogenation of 3,3‐dimethylbiphenyl, which is a product of direct desulfurization of 4,6‐DMDBT. The smallest 4 nm particles provided unprecedented (for Pd at 5 MPa and 300 °C) direct desulfurization selectivity of 20 % at 40 % conversion because of the reduced contribution of the hydrogenation path. The 4 nm particles were poisoned by the adsorbed sulfur to the greatest extent. The optimal size, providing the highest Pd mass‐based yield of the desulfurized products, was found to be 8 nm. The catalyst with 87 nm particles was based on Pd nanocubes with the lowest edge/terrace surface atom ratio and large terraces and this showed the lowest sulfur extraction from both 4,6‐DMDBT and sulfurous intermediates as a result of the low availability of edge atoms for a perpendicular sigma‐mode adsorption through the lone pair of the sulfur atom.
Origin of the Improved Performance in Lanthanum‐doped Silica‐supported Ni Catalysts
Authors: Baudouin David , Margossian Tigran , Rodemerck Uwe , Webb Paul B. , Veyre Laurent , Krumeich Frank , Candy Jean‐Pierre , Thieuleux Chloé , Copéret Christophe
Published: July 2016

Dry‐reforming catalysts were prepared by supporting Ni nanoparticles (2–3 nm) on La‐doped silica. These materials display higher activity and stability in low‐temperature dry reforming (773 K) than Ni/SiO2 or Ni/La2O3. The La‐doped silica‐supported catalysts were found to have exclusively lanthanum silicate at their surface rather than La2O3 and/or SiO2. While an increasing amount of La was found to favor both CO2 adsorption capacity and strength, it also influenced the hydrogen adsorption strength on nickel particles significantly, as evidenced by H2 temperature‐programmed desorption analysis. Finally, CH4 temperature‐programmed reduction analysis revealed that the CH4 cracking threshold temperature varies in the order: Nibulk<Ni/La34@SiO2<Ni/La2.1@SiO2≪Ni/SiO2<Ni/La2O3, which parallels the catalytic performance. Balancing the adsorption of CH4, H2, and CO2 on supported Ni nanoparticles (2–3 nm) on La‐doped silica improves the catalytic performance of this low‐temperature dry‐reforming catalyst.
Bioprospecting of Halotolerant Bacterial Isolates for Potassium Recovery from K‐Feldspar
Authors: Bachani Pooja , Bhattacharya Sourish , Jain Deepti , Patidar Shailesh Kumar , Soundarya Rajapitamahuni , Tirkey Sushma Rani , Ranawat Bablesh , Bharadwaj S. V. Vamsi , Mishra Sandhya
Published: July 2016

Potassium‐solubilizing bacteria were isolated from solar salt pans of an experimental salt farm and Sambhar Lake, mining areas of Naseerabad, and wastewater from a marble cutting machinery. Seven promising bacterial isolates from Makrana, three from Sambhar Lake, and three from Naseerabad were found to have comparatively better potassium‐solubilizing capacity. Out of these, three potential bacterial isolates were identified as Acinetobacter soli (MTCC 5918), Enterobacter xiangfangensis (MTCC 5917), and Acinetobacter baumannii (MTCC 5916). A. soli was found to have maximum potassium‐releasing capacity in the supernatant which may be further applied as a biofertilizer.
Laser Ablation Synthesis of Gold Selenides by using a Mass Spectrometer as a Synthesizer: Laser Desorption Ionization Time‐of‐Flight Mass Spectrometry
Authors: Prokeš Lubomír , Kubáček Pavel , Peña‐Méndez Eladia Maria , Amato Filippo , Conde José Elias , Alberti Milan , Havel Josef
Published: July 2016

Methods for the rapid construction of new chemical motifs have the potential to accelerate the development of nanoscience. The synthesis of new chemical entities by laser ablation has been systematically demonstrated by using mixtures of gold and selenium. The compounds generated are detected by time‐of‐flight mass spectrometry and, for selected compounds, the structure is investigated by using density functional theory optimization. In total, 67 new gold selenide clusters have been synthesized, demonstrating an unsuspected richness in gold chemistry. Chemical species generated in the gas phase might inspire new routes for the synthesis of novel compounds in the solid state.
Interactions of Isonitriles with Metal–Boron Bonds: Insertions, Coupling, Ring Formation, and Liberation of Monovalent Boron
Authors: Braunschweig Holger , Celik Mehmet Ali , Dewhurst Rian D. , Ferkinghoff Katharina , Hermann Alexander , Jimenez‐Halla J. Oscar C. , Kramer Thomas , Radacki Krzysztof , Shang Rong , Siedler Eva , Weißenberger Felix , Werner Christine
Published: July 2016

Boryl, borylene, and base‐stabilized borylene complexes of manganese and iron undergo a range of different reactions when treated with isonitriles including single, double, and partial isonitrile insertions into metal−boron bonds, ring formation, isonitrile coupling, and the liberation of new monovalent boron species. Two of the resulting cyclic species have also been found to react selectively with anhydrous HCl to form ring‐opened products. The diverse isonitrile‐promoted reactivity of transition‐metal–boron compounds has been explored computationally.
How do you write and present research well? 17—Submit your manuscript to the journal you cite most
Authors: Patience Gregory S. , Boffito Daria C. , Patience Paul A.
Published: July 2016

More people have cited Axel Becke's article on Density Functional Thermochemistry[1] than any other article between 1989 and 2014—over 45 000. How many citations has WoS indexed for the most cited chemical engineering paper?[2,3]

less than 1000

between 1000 and 5000

between 5000 and 10 000

more than 10 000
Henry Enfield Roscoe – Wegbereiter der Chemie im Großbritannien des 19. Jahrhunderts
Authors: Remane Horst , Bartel Hans‐Georg
Published: July 2016

Der Beitrag erinnert aus Anlass des 100. Todestages an den bedeutenden britischen Chemiker Henry Enfield Roscoe (1833–1915). Nach dem Abschluss des Studiums der Chemie als Bachelor of Arts an der Universität London 1853 ging dieser zu Robert Bunsen (1811–1899) nach Heidelberg. Dort wurde er nach der Promotion (mit „summa cum laude“) dessen Assistent. Zusammen mit seinem Lehrer und Freund Bunsen hat Roscoe die grundlegenden Studien über die chemische Wirkung des Lichts („Photochemische Untersuchungen“) durchgeführt. Er trug ebenfalls zur Forschung und Anwendung der damals noch neuen Spektralanalyse von Bunsen und Gustav Robert Kirchhoff (1824–1887) bei. Nach seiner Rückkehr nach Großbritannien wurde Roscoe Professor für Chemie am Owens College in Manchester (seit 1880 Universität). In den ungefähr dreißig Jahren seiner dortigen Tätigkeit trug er maßgeblich zur Etablierung einer modernen chemischen Ausbildung und Forschung in seinem Lande bei. Ihm gelang als Erstem die Darstellung von metallischem Vanadium, indem er Vanadium(II)‐chlorid mit Wasserstoff reduzierte. Bei seinen systematischen Untersuchungen von Wolframverbindungen gelang ihm die Darstellung und Charakterisierung zahlreicher noch nicht bekannter Vertreter. Roscoe konnte beweisen, dass das hypothetische chemische Element Philippium ein Gemisch aus Terbium und Yttrium ist. Darüber hinaus war Roscoe sehr erfolgreich als Wissenschaftsorganisator und ‐politiker, aber auch als Autor von umfangreichen Lehrbüchern der Chemie tätig.