bluuebunny/crossref_metadata_2025 huggingface dataset:
Interview with Jo Graham, Melissa Scott, and Martha Wells
Authors: Editor TWC
Published: September 2010

An interview with Jo Graham, Melissa Scott, and Martha Wells, who are professional authors of original fiction and media tie-in novels in addition to writing fan fiction.
Development of a Novel Fluorescence Assay Based on the Use of the Thrombin‐Binding Aptamer for the Detection of O6‐Alkylguanine‐DNA Alkyltransferase Activity
Authors: Tintoré Maria , Aviñó Anna , Ruiz Federico M. , Eritja Ramón , Fàbrega Carme
Published: September 2010

Human O6‐alkylguanine‐DNA alkyltransferase (hAGT) is a DNA repair protein that reverses the effects of alkylating agents by removing DNA adducts from the O6 position of guanine. Here, we developed a real‐time fluorescence hAGT activity assay that is based on the detection of conformational changes of the thrombin‐binding aptamer (TBA). The quadruplex structure of TBA is disrupted when a central guanine is replaced by an O6‐methyl‐guanine. The sequence also contains a fluorophore (fluorescein) and a quencher (dabsyl) attached to the opposite ends. In the unfolded structure, the fluorophore and the quencher are separated. When hAGT removes the methyl group from the central guanine of TBA, it folds back immediately into its quadruplex structure. Consequently, the fluorophore and the quencher come into close proximity, thereby resulting in decreased fluorescence intensity. Here, we developed a new method to quantify the hAGT without using radioactivity. This new fluorescence resonance energy transfer assay has been designed to detect the conformational change of TBA that is induced by the removal of the O6‐methyl group.
Mesalamine-Induced Myocarditis
Authors: Merceron Olivier , Bailly Clement , Khalil Antoine , Pontnau Florence , Hammoudi Nadjib , Dorent Richard , Michel Pierre-Louis
Published: September 2010

Nowadays mesalamine is a common treatment for Crohn's disease and hypersensitive reactions to this product have been reported. Yet there is limited information concerning mesalamine-induced myocarditis and its mechanism is not known. We described a case of mesalamine-induced myocarditis in Crohn's disease of the colon.
Liquid and Frozen Storage of Agouti (Dasyprocta leporina) Semen Extended with UHT Milk, Unpasteurized Coconut Water, and Pasteurized Coconut Water
Authors: Mollineau W. M. , Adogwa A. O. , Garcia G. W.
Published: September 2010

This study evaluated the effects of semen extension and storage on forward progressive motility % (FPM%) in agouti semen. Three extenders were used; sterilized whole cow's milk (UHT Milk), unpasteurized (CW) and pasteurized coconut water (PCW), and diluted to 50, 100, 150, and 200 × 106spermatozoa/ml. Experiment 1: 200 ejaculates were extended for liquid storage at 5∘C and evaluated every day for 5 days to determine FPM% and its rate of deterioration. Experiment 2: 150 ejaculates were extended for storage as frozen pellets in liquid nitrogen at −195∘C, thawed at 30∘to 70∘C for 20 to 50 seconds after 5 days and evaluated for FPM% and its rate of deterioration. Samples treated with UHT milk and storage at concentrations of 100 × 106spermatozoa/ml produced the highest means for FPM% and the slowest rates of deterioration during Experiment 1. During Experiment 2 samples thawed at 30∘C for 20 seconds exhibited the highest means for FPM% (12.18 ± 1.33%), 85% rate of deterioration. However, samples were incompletely thawed. This was attributed to the diameter of the frozen pellets which was 1 cm. It was concluded that the liquid storage method was better for short term storage.
Pictorial Essay: Infants of diabetic mothers
Authors: Alorainy Ibrahim A , Barlas Nauman B , Al-Boukai Amer A
Published: September 2010

About 3 to 10% of pregnancies are complicated by glycemic control abnormalities. Maternal diabetes results in significantly greater risk for antenatal, perinatal, and neonatal morbidity and mortality, as well as congenital malformations. The number of diabetic mothers is expected to rise, as more and more of the obese pediatric female population in developed and some developing countries progresses to childbearing age. Radiologists, being part of the teams managing such pregnancies, should be well aware of the findings that may be encountered in infants of diabetic mothers. Timely, accurate, and proper radiological evaluation can reduce morbidity and mortality in these infants. The purpose of this essay is to illustrate the imaging findings in the various pathological conditions involving the major body systems in the offspring of women with diabetes
Case report: MR spectroscopy in pantothenate kinase-2 associated neurodegeneration
Authors: Parashari Umesh C , Aga Pallavi , Parihar Anit , Singh Ragini , Joshi Vindhya
Published: September 2010

We report a case of a 13-year-old girl with Hallervorden-Spatz disease (HSD) or pantothenate kinase-2 associated neurodegeneration (PKAN). HSD is a rare neurodegenerative disorder, which is characterized by a rapidly progressive extrapyramidal syndrome, dementia with optic atrophy, and retinal degeneration. It is associated with accumulation of cysteine-iron complex in the globus pallidi and substantia nigra. The MRI "eye of the tiger" sign is the characteristic. MRI spectroscopy is also characteristic. It shows markedly decreased NAA/Cr values in the globus pallidi and substantia nigra with increased mI/Cr values that suggest of gliosis.
Diffusion-weighted magnetic resonance imaging in acute reversible toxic leukoencephalopathy: A report of two cases
Authors: Sivasubramanian S , Moorthy Srikant , Sreekumar KP , Kannan R Rajesh
Published: September 2010

Acute toxic leukoencephalopathy may be caused by endogenous or exogenous toxins. It may reverse clinically if the offending agent is withdrawn or the underlying condition is treated. However, demonstration of reversibility on imaging, especially with diffusion-weighted MRI, has been reported only very recently. We report two such cases.
Case report: Cervical spinal cord signal changes in a case of adult-onset subacute sclerosing panenchephalitis
Authors: Sharma Sandeep , Kumar Subhash
Published: September 2010

In this article, we report a case of subacute sclerosing panencephalitis (SSPE) in which there were central cervical cord signal changes on MRI. The spinal cord is uncommonly involved in SSPE. However, demonstration of spinal cord signal change in a patient of SSPE has significant implications for the differential diagnosis and management
Prevalence of lower extremity venous duplication
Authors: Simpson William L , Krakowsi David
Published: September 2010

Purpose: This retrospective study was performed to determine the prevalence of lower extremity venous duplication using duplex ultrasound in the patient population of a large urban medical center. Materials and Methods: The reports of all lower extremity venous ultrasound examinations performed at our institution between January 1, 2002 and December 31, 2002 were reviewed. Ultrasound examinations that were performed for purposes other than the detection of lower extremity deep vein thrombosis were excluded. The prevalence of duplication and its specific location were recorded. In addition, the prevalence of thrombus and its specific location were also recorded. Results: A total of 3118 exams were performed in 2664 patients. Of the 2664 patients, 2311 had only one examination performed during the study period; 353 patients had more than one examination performed. We found that 10.1% of patients (270/2664) had at least one venous segment duplicated and 5.4% of patients (143/2664) had a thrombus in at least one venous segment. There was a statistically significant difference in the prevalence of both duplication and thrombus with a change in venous segment. Only 0.4% of patients (11/2664) had thrombus within a duplicated segment. Of those who had more than one examination performed, 15.3% (54/353) had the same venous segment(s) seen on one examination but not another. Conclusion: Lower extremity venous duplication is a frequent anatomic variant that is seen in 10.1% of patients, but it may not be as common as is generally believed. It can result in a false negative result for deep vein thrombosis.
Flash floods in Catalonia: a recurrent situation
Authors: Llasat M. C. , Llasat-Botija M. , Rodriguez A. , Lindbergh S.
Published: September 2010

Abstract. This work focuses on the analysis and characterization of the flash flood events occurring during summer in Catalonia. To this aim, a database with information about the social impact produced by all flood events recorded in Catalonia between 1982 and 2007 has been built. The social impact was obtained systematically on the basis of news press data and, occasionally, on the basis of insurance data. Flood events have been classified into ordinary, extraordinary and catastrophic floods, following the proposal of Llasat et al.~(2005). However, bearing in mind flash flood effects, some new categories concerning casualties and car damage have also been introduced. The spatial and temporal distribution of these flood events has been analyzed and, in an effort to better estimate the social impact and vulnerability, some indicators have been defined and analyzed for a specific region. These indicators allow an analysis of spacial and temporal trends as well as characterization of the events. Results show a flash-flood increase in summer and early autumn, mainly due to inter-annual and intra-annual changes in population density.
CAMBIOS EN LA FERTILIDAD DEL SUELO, PRODUCCIÓN DE BIOMASA Y BALANCE DE NITRÓGENO EN SISTEMAS AGROFORESTALES CON CAFÉ EN NICARAGUA
Authors: Munguía-Hernández Rodolfo , Haggar Jeremy , Silvio-Ponce Alejandro
Published: September 2010

Se estableció un experimento de un sistema agroforestal con el cultivo de café en el año 2001 en el Municipio de Masatepe, Nicaragua; estableciéndose en las parcelas principales especies arbóreas leguninosas y no leguminosas y en las subparcelas niveles de fertilizantes orgánicos y químicos aplicados a diferentes cantidades para el manejo de la fertilidad del suelo, enfermedades, plagas insectiles y malezas, con el propósito de establecer los cambios en la fertilidad del suelo, la producción de residuos vegetales y el balance de Nitrógeno. Para la determinación de las variables del suelo, mineralización del nitrógeno, carbono y biomasa microbiana se extrajo por parcela experimental un volumen de suelo para constituir una muestra compuesta. Para la producción de biomasa fueron muestreados dos árboles por parcela y determinados los contenidos de N; fue considerada la cantidad de N aportados por la adición de fertilizantes orgánicas y químicos. El N extraído por medio de la cosecha (grano uva) fue determinado para incluirlo en el balance. Los resultados muestran que se produce una menor acidez del suelo, y estadísticamente diferente en el Orgánico Intensivo comparado al manejo Convencional Moderado, y similar comportamiento en Fósforo, Potasio y la biomasa microbiana. En tanto la CIC, el N y el C total, resultó menor en el 2004 con respecto al 2001, en ambos años no hubo diferencias estadísticas entre los tratamientos. La tasa de mineralización del N es menor en el tratamiento a pleno sol con fertilizante químico con respecto a los tratamientos con sombra arbórea; mientras que los fertilizantes orgánicos muestran ser diferentes estadísticamente con respecto a fertilizantes químicos aplicados al suelo. Las cantidades de residuos vegetales producidos por la poda es dado por Inga. laurina, sin embargo, en el raleo Tabebuia. rosea la supera en esta actividad. El balance de Nitrógeno resulta negativo en los niveles de fertilizante Moderado Convencional y Orgánico Moderado dado que las extracciones por cosecha de los frutos de café y extracciones de leña son superiores a las adiciones de N vía fertilización provocando un empobrecimiento de este elemento mineral en el suelo. Palabras clave: Orgánico, Convencional, Leguminosas, Balance de Nitrógeno, Biomasa, Simarouba glauca, Tabebuia rosea, Inga laurina, Samanea samanDOI: 10.5377/calera.v10i14.22
EVALUACION DEL RENDIMIENTO DE SORGO VARIEDAD CNIA-INTA BAJO DISTINTAS FUENTES DE SUMINISTRO DEL NITROGENO
Authors: García-Centeno Leonardo , Tellez Orlando , Mason Stephen C
Published: September 2010

Dada la importancia del cultivo de sorgo para pequeños y medianos productores nicaragüenses y su utilización para la producción de grano, la Universidad Nacional Agraria y el Programa INTSORMIL, desde el año 2000 evaluaron distintos materiales de sorgo. Después de tres años de resultados, se seleccionó la variedad CNIA-INTA por su buen rendimiento de grano para ser sometido a niveles bajos de fertilización (práctica del pequeño productor) y a un método alternativo que incluyen el uso de abono verde (Vigna radiata L.), como fuente de N. Con este propósito tres ensayos se establecieron en el ciclo de postrera del 2004. El primero en Tisma, Departamento de Masaya, el segundo en el Centro Experimental de Occidente (CEO) en el Municipio de Posoltega, departamento de Chinandega y el tercero en San Ramón, Matagalpa, en la Comunidad Guadalupe, ubicada a 10 km. de la cabecera departamental. Se utilizó un diseño de bloques completos al azar (BCA), con cuatro repeticiones. Cada parcela constituida de siete surcos de cinco m de largo, separados a 0.60 m. Se utilizaron los cuatro surcos centrales como parcela útil para muestreos de las variables a evaluar. El análisis de varianza mostró diferencias altamente significativas entre localidades y tratamientos y para localidad x tratamiento para el rendimiento de grano (RG). Los tratamientos urea (toda) a la siembra (6 078 kg ha-1) y Mungo (5 655 kg ha-1) fueron estadísticamente iguales y ambos se diferenciaron del tratamiento urea fraccionada (4 488 kg ha-1). Entre localidades, Tisma obtuvo el mayor rendimiento con 7,259 kg -1 superior al obtenido en el CEO, con 3 933 kg ha-1. No se encontraron diferencias entre tratamientos en el peso de mil granos y rendimiento de biomasa (RB), sin embargo, en San Ramón se obtuvo el mayor peso (26.74 g) y el menor en CEO (23.78 g). La forma de suministrar nitrógeno no tuvo efecto sobre la materia seca producida, sin embargo, el tratamiento con mungo, superó ligeramente a la biomasa producida con fertilización química. El mismo comportamiento se obtuvo para esta variable entre localidades. Se obtuvo interacción positiva entre localidad x tratamiento, siendo en Tisma donde se alcanzan los mayores rendimientos cuando se aplica el N 30 días después de la siembra (dds). El uso de mungo, presentó el segundo mejor rendimiento en las dos localidades antes mencionadas.DOI: 10.5377/calera.v10i14.24
INTOXICACIÓN EXPERIMENTAL EN TERNEROS HOLSTEIN CON Ageratum houstonianum Mill (Celestina azul) Y Lantana camara L. (Filigrana, Verbena Morada, Cinco negritos)
Authors: Aparicio-Medina José Manuel , Paredes-Vanegas Varinia
Published: September 2010

La fotosensibilización hepatógena se estudia por los servicios veterinarios desde el siglo pasado, estableciéndose una de las causales de ésta enfermedad la Lantana camara (verbena morada), donde los animales presentaban hemorragias y dermatitis, no reportándose la presencia de plantas fotosensibilizadoras, ni dermatitis ocasionada por otra causa según los resultados laboratoriales, sólo la evidencia del consumo junto al forraje de la planta Ageratum houstonianum Mill. El objetivo de este trabajo es evaluar algunos efectos tóxicos de las plantas A. houstonianum y L. camara en terneros y se realizó a partir de la formación de dos grupos de animales (terneros) intoxicados experimentalmente con A. houstonianum y L. camara basado en las regulaciones de bienestar animal para los casos estudiados. Se estudiaron aspectos relacionados con la triada, tiempo de sangramiento y de coagulación en los que hubo evidencias de alteración para los parámetros fisiológicos de la especie en los animales tratados. Los análisis estadísticos se basaron en t student y regresión lineal. Palabras clave: Plantas fotosensibilizantes, fotosensibilización, hemorragias, dermatitis, Intoxicación por plantasDOI: 10.5377/calera.v10i14.28
UNA PROPUESTA DIFERENTE PARA ERRADICAR LA POBREZA RURAL: TRANSFORMAR LOS AFECTADOS POR EL SUBDESARROLLO EN CONSTRUCTORES DEL DESARROLLO
Authors: Lacki Polan
Published: September 2010

DOI: 10.5377/calera.v10i14.30
FACTORES QUE INCIDEN EN EL NIVEL DE POBREZA DE LAS FAMILIAS CAMPESINAS EN LAS COMUNIDADES DE LA MONTAÑITA UNO Y LA MONTAÑITA DOS, MUNICIPIO DE TISMA, MASAYA
Authors: Medioroz Yvette Sánchez , Viachica Elgin Antonio Vivas
Published: September 2010

Este estudio se realizó en las comunidades de La Montañita1 y La Montañita 2 del Municipio de Tisma, Departamentode Masaya, en el año 2002. Se aplicaron 30 encuestas porcomunidad. Las comunidades de "La Montañita 1" y "LaMontañita 2" del Municipio de Tisma, Departamento deMasaya tienen una población mayoritariamente analfabeta, unfactor que incide negativamente en elevar el nivel de vida delas familias campesinas y se constituye en una dificultad paraemprender acciones de desarrollo y erradicación de la pobreza acorto plazo. Un segmento las poblaciones de estas comunidadestienen nivel académico de primaria incompleta, siendopotencialmente analfabetos; y otro porcentaje (13.2% y 27.1%Montañita 1 y 2 respectivamente) nunca han recibido ningúntipo de formación. La capacitación de estas comunidades hasido insignificante, debido a que el 89.1% no ha recibidoningún tipo de capacitación y solamente el 10.9% dice haberrecibido. De las personas que han recibido capacitación, el 4%lo ha hecho solamente una vez, esto nos indica que en estascomunidades los proyectos no han priorizado la capacitacióncomo estrategia de desarrollo y mejoramiento del nivel devida. Es importante mencionar que el 47.7% dice que nadieha llegado a capacitar y el 16.7% piensa que no tiene tiempodisponible para participar en este tipo de actividades. Otrofactor importante a considerar en el mejoramiento del nivel devida de las comunidades rurales es la organización comunitaria,no pertenecía a ningún tipo de organización y el 14.3% no tuvovínculos con alguna organización. Además, el 85.5% dice nohaber ningún tipo de beneficio.Palabras clave: Pobreza; Analfabetismo y Nivel de VidaDOI: 10.5377/calera.v9i13.13
DISPONIBILIDAD Y ACCESO A LOS ALIMENTOS DE POBLADORES RURALES DEL MUNICIPIO DE SAN JOSÉ DE CUSMAPA, MADRIZ EN EL AÑO 2008
Authors: Rodríguez Pedro Noel Torrez , Blandón Indania Del Socorro Montes , Martinez Iris Lucía Manzanares
Published: September 2010

El tema disponibilidad y acceso se enmarca dentro dela seguridad alimentaria y nutricional; específicamente,es un análisis de las variables disponibilidad, acceso yaprovechamiento de alimentos de los pobladores ruralesdel Municipio de San José de Cusmapa (El Mojón, ElRodeo, Los Llanitos, Los Ángeles I, II III, San Franciscode Imires y La Fuente). En el estudio se planteó disponerde información respecto a la situación alimentaria de lalocalidad, para que los decisores orienten líneas, políticas yestrategias en función de mejorar la calidad de vida de lospobladores rurales del municipio. La metodología utilizadafue participativa con pobladores rurales de San José,líderes comunales, representantes de ONG's, autoridadesmunicipales, del Ministerio de Educación y Salud. Ellosbrindaron información que fue recopilada a través de laobservación, encuestas y entrevistas que luego, fue analizaday presentada ante las autoridades locales de las cualessurgieron sugerencias que fueron incorporadas al estudio.Se seleccionó a las comunidades de San José de Cusmapaporque representan el 87.1% de extrema pobreza, según mapade pobreza de Nicaragua realizado en el 2001. Con relacióna la variable disponibilidad, los resultados demostraron queel 71.4% de la población no logra satisfacer sus necesidadesalimenticias, cifra coincidente con el estudio de pobreza del2001. Respecto al acceso a los alimentos, sólo un 10.2% depobladores tiene un acceso pleno y suficiente a los mismos;el 79.6% sólo a medias lo logra, y el 10.2% lo hace deforma insuficiente. Sobre higiene uso y aprovechamiento delos alimentos, un 93.9% de la población conoce y hace usoadecuado de los mismos. Ello se explica porque la mayoríade los pobladores han recibido capacitación al respecto. SanJosé de Cusmapa presenta una aguda situación de inseguridadalimentaria, debido a que solo un 28.6% de sus pobladoresdispone de alimentos seguros y estables; un 10.2% tiene accesoa los alimentos y el 90% aprovecha y utiliza higiénicamente losalimentos poco disponible y accesible. Los factores de riesgosde la seguridad alimentaria están asociados a las prolongadassequías, insuficientes factores de producción, bajo rendimientode cultivos, alta incidencia de plagas y enfermedades, escasezde fuentes de agua y semillas, poca presencia y apoyo deorganizaciones y los altos precios de los alimentos.Palabras clave: Seguridad alimentaria y nutricional;disponibilidad; acceso; higiene y aprovechamiento dealimentos.DOI: 10.5377/calera.v9i13.14
UTILIDAD DE MARCADORES RAPD EN LA CARACTERIZACIÓN MOLECULAR DE QUEQUISQUE (Xanthosoma spp.) DE NICARAGUA. ESTUDIO PRELIMINAR
Authors: Reyes-Castro Guillermo
Published: September 2010

El quequisque es un cultivo de importancia en los trópicos ysubtrópicos por ser fuente de alimento y recursos para productores.Nicaragua está ubicada en el centro de origen del géneroXanthosoma, donde pueden encontrarse muchas especies silvestresde uso potencial. Sin embargo, la información sobre la relacióngenética inter e intra específica es escasa. Se evaluó el uso de losmarcadores moleculares generados por 40 cebadores RAPD (kitsB y D, Operon technologies) en la caracterización de especies delgénero Xanthosoma colectados en Nicaragua. Con tal fin se extrajoADN de vitroplantas de tres especies Xanthosoma silvestres ycuatro cultivadas, cuatro Alocasia ornamentales y tres Colocasiacultivadas. Los marcadores moleculares generados fueronsometidos al análisis fenético utilizando el programa Neighbourjoining. Catorce de los cebadores revelaron polimorfismo entrelos genotipos. El dendograma generado agrupó las Xanthosomacultivadas y silvestres, exceptuando X mexicum. Las especiesColocasia y Alocasia no formaron un grupo claro. Este estudioconfirma la variación genética en las especies Xanthosomasilvestres y cultivadas creciendo en Nicaragua. Los marcadoresmoleculares generados por los catorce cebadores RAPD puedenser utilizados para la caracterización molecular del banco degermoplasma del género Xanthosoma colectado en el país.Palabras clave: Xanthosoma; marcadores moleculares;diversidad genética; RADSDOI: 10.5377/calera.v9i13.18
Bioinspired Water‐Vapor‐Responsive Organic/Inorganic Hybrid One‐Dimensional Photonic Crystals with Tunable Full‐Color Stop Band
Authors: Wang Zhanhua , Zhang Junhu , Xie Jing , Li Chuang , Li Yunfeng , Liang Sen , Tian Zhicheng , Wang Tieqiang , Zhang Hao , Li Haibo , Xu Weiqing , Yang Bai
Published: September 2010

Bioinspired organic/inorganic hybrid one‐dimensional photonic crystals (1DPCs) are prepared by alternating thin films of titania and poly(2‐hydroxyethyl methacrylate‐co‐glycidyl methacrylate) (PHEMA‐co‐PGMA) by spin‐coating, which is a simple, reproducible, and low‐cost approach. Their optical properties are tuned by changing the number of layers, incident angles, and the thickness of the layers. The color of the 1DPCs can span the entire visible spectral range when the period or the refractive index is changed. Due to the response of PHEMA‐co‐PGMA to water vapor, the 1DPCs possess fast water‐vapor responsiveness and reversible full‐color switching. The color of the 1DPCs varies from blue to green, yellow, orange, and red under differing humidities, covering the whole visible range. At high water‐vapor concentrations, the color of the 1DPCs rapidly changes from blue to red and comes back to the original state immediately after exposure to air; this behaviour is like that of some animals in nature. The repeatability of the reversible response of the 1DPCs to water vapor is perfect and can be repeated more than 100 times. The as‐prepared 1DPCs successfully combine structural color and water‐vapor sensitivity, which is promising for use as materials for colorful detection across the full color range.
Self‐Propagating Domino‐like Reactions in Oxidized Graphite
Authors: Kim Franklin , Luo Jiayan , Cruz‐Silva Rodolfo , Cote Laura J. , Sohn Kwonnam , Huang Jiaxing
Published: September 2010

Graphite oxide (GO) has received extensive interest as a precursor for the bulk production of graphene‐based materials. Here, the highly energetic nature of GO, noted from the self‐propagating thermal deoxygenating reaction observed in solid state, is explored. Although the resulting graphene product is quite stable against combustion even in a natural gas flame, its thermal stability is significantly reduced when contaminated with potassium salt by‐products left from GO synthesis. In particular, the contaminated GO becomes highly flammable. A gentle touch with a hot soldering iron can trigger violent, catastrophic, total combustion of such GO films, which poses a serious fire hazard. This highlights the need for efficient sample purification methods. Typically, purification of GO is hindered by its tendency to gelate as the pH value increases during rinsing. A two‐step, acid–acetone washing procedure is found to be effective for suppressing gelation and thus facilitating purification. Salt‐induced flammability is alarming for the fire safety of large‐scale manufacturing, processing, and storage of GO materials. However, the energy released from the deoxygenation of GO can also be harnessed to drive new reactions for creating graphene‐based hybrid materials. Through such domino‐like reactions, graphene sheets decorated with metal and metal oxide particles are synthesized using GO as the in situ power source. Enhanced electrochemical capacitance is observed for graphene sheets loaded with RuO2 nanoparticles.
Engineering the Extracellular Environment: Strategies for Building 2D and 3D Cellular Structures
Authors: Guillame‐Gentil Orane , Semenov Oleg , Roca Ana Sala , Groth Thomas , Zahn Raphael , Vörös Janos , Zenobi‐Wong Marcy
Published: September 2010

Cell fate is regulated by extracellular environmental signals. Receptor specific interaction of the cell with proteins, glycans, soluble factors as well as neighboring cells can steer cells towards proliferation, differentiation, apoptosis or migration. In this review, approaches to build cellular structures by engineering aspects of the extracellular environment are described. These methods include non‐specific modifications to control the wettability and stiffness of surfaces using self‐assembled monolayers (SAMs) and polyelectrolyte multilayers (PEMs) as well as methods where the temporal activation and spatial distribution of adhesion ligands is controlled. Building on these techniques, construction of two‐dimensional cell sheets using temperature sensitive polymers or electrochemical dissolution is described together with current applications of these grafts in the clinical arena. Finally, methods to pattern cells in three‐dimensions as well as to functionalize the 3D environment with biologic motifs take us one step closer to being able to engineer multicellular tissues and organs.
OLEDs: Degradation Mechanisms in Small‐Molecule and Polymer Organic Light‐Emitting Diodes (Adv. Mater. 34/2010)
Authors: So Franky , Kondakov Denis
Published: September 2010

Degradation in organic light‐emitting diodes (OLEDs) is a complex problem. Depending upon the materials and the device architectures used, the degradation mechanism can be very different. In this Progress Report, using examples in both small molecule and polymer OLEDs, the different degradation mechanisms in two types of devices are examined. Some of the extrinsic and intrinsic degradation mechanisms in OLEDs are reviewed, and recent work on degradation studies of both small‐molecule and polymer OLEDs is presented. For small‐molecule OLEDs, the operational degradation of exemplary fluorescent devices is dominated by chemical transformations in the vicinity of the recombination zone. The accumulation of degradation products results in coupled phenomena of luminance‐efficiency loss and operating‐voltage rise. For polymer OLEDs, it is shown how the charge‐transport and injection properties affect the device lifetime. Further, it is shown how the charge balance is controlled by interlayers at the anode contact, and their effects on the device lifetime are discussed.
Copper(II) Triflate‐Catalyzed Intramolecular Hydroamination of Homoallylic Amino Alcohols as an Expedient Route to trans‐2,5‐Dihydro‐1H‐pyrroles and 1,2‐Dihydroquinolines
Authors: Rao Weidong , Kothandaraman Prasath , Koh Chii Boon , Chan Philip Wai Hong
Published: September 2010

A new efficient synthetic route to trans‐2,5‐dihydro‐1H‐pyrroles and 1,2‐dihydroquinolines that relies on copper(II) triflate‐catalyzed intramolecular hydroamination of homoallylic amino alcohols under mild and operationally straightforward conditions is described. For reactions leading to the trans‐2,5‐dihydro‐1H‐pyrrole product, yields of 52–83% along with trans selectivities up to >99:1 dr and ee values up to 97% were accomplished from enantioenriched 1‐(tosylamino)pent‐4‐en‐2‐ols ranging from 91–99% ee. Without the need for inert and moisture‐free conditions, reactions involving 1‐[2‐ (tosylamino)phenyl]but‐3‐en‐1‐ols afforded the corresponding 1,2‐dihydroquinoline products in excellent yields up to 99% and with complete chemoselectivity. The mechanism is suggested to involve cop‐ per(II)‐mediated dehydration of the homoallylic amino alcohol. Protonation of the resultant cop‐ per(II)‐activated aminodiene is then thought to trigger subsequent intramolecular hydroamination to give the partially hydrogenated nitrogen heterocycle.
Thermodynamic analysis of capillary flows in the presence of hydrodynamic slip
Authors: Laouir A. , Tondeur D.
Published: September 2010

A thermodynamic description of liquid flows in capillaries with hydrodynamic slip at the solid–liquid interface is given. Slip over the capillary wall brings into play surface interactions and therefore involves interfacial energy and entropy. Energy and entropy balance equations are written so as to take into account surface effects. The two relations constitute a general mathematical model that allows readily analyzing various situations and to explore the behavior of such thermodynamic process. The main result derived concerns the existence of a capillary pressure of slip; slip occurrence leads to a pressure decrease in the flow and might cause cavitation. The variation in magnitude of the slip effect, viewed as a thermodynamic transformation, may take place irreversibly. Slip irreversibility and the probable occurrence of a two‐phase flow regime are possible factors that may cause additional pressure drop. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Thermal dissociation of compressed ZnO and SnO2 powders in a moving‐front solar thermochemical reactor
Authors: Chambon Marc , Abanades Stéphane , Flamant Gilles
Published: September 2010

The high‐temperature thermal dissociation reaction of ZnO and SnO2 was investigated, as part of a two‐step thermochemical water‐splitting cycle for H2 production. A lab‐scale solar reactor (1 kW) was designed, built, and operated for continuous dissociation of volatile oxides under reduced pressure. In this reactor, compressed oxide powders placed in a vertical ceramic cavity are irradiated by highly concentrated solar energy. The reactor design allows moving the reaction front for achieving continuous reactant feeding. ZnO and SnO2 thermal dissociations were successfully performed at about 1900 K, with the recovery of up to 50% of products as nanopowders with high specific surface area (in the range 20–60 m2/g) and with mass fractions of reduced species up to 48 wt % for Zn and 72 wt % for SnO. The performed O2 measurements confirmed the kinetics of ZnO dissociation and gave an activation energy of 380 ± 16 kJ/mol, based on an ablation regime of the ZnO surface. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Monitoring of minimal residual disease in acute myeloid leukemia with frequent and rare patient‐specific NPM1 mutations
Authors: Dvorakova Dana , Racil Zdenek , Jeziskova Ivana , Palasek Ivo , Protivankova Marketa , Lengerova Martina , Razga Filip , Mayer Jiri
Published: September 2010

Nucleophosmin (NPM1) mutations in exon 12 are the most common genetic alternation in cytogenetically normal AML (CN‐AML). Although mutation types A, B, and D represent the majority of cases, rare mutation variants of the NPM1 gene in individual patients do occur. In this study, we have evaluated a novel, DNA‐based real‐time quantitative polymerase chain reaction (RQ‐PCR) for the detection of three of the most commonly occurring mutations and for six rare patient‐specific mutation types, which represent 28% of all of the NPM1 mutations in our group of 25 CN‐AML patients. Furthermore, the prognostic relevance of NPM1‐based monitoring of minimal residual disease (MRD) in peripheral blood (PB), bone marrow (BM), and in specific cell subsets (CD34+, CD34−, CD34dim) of BM were evaluated. In 80% of the evaluable patients, a molecular relapse preceded a hematological relapse. Moreover, in this subset of patients, the molecular relapse occurred at a median of 97 days before the hematological relapse. Our compartment analysis showed a strong correlation between BM and PB (r = 0.907, P < 0.001) as well as a high copy number of mutated NPM1 in CD34+ BM cells. In conclusion, we have demonstrated applicability of our presented RQ‐PCR method for a large percentage of mutated NPM1 patients with CN‐AML as well as the usefulness for long‐term follow‐up monitoring of MRD and the prediction of hematological relapse. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Transport of copper, nickel and zinc ions across ultrafiltration membrane based on modified polysulfone and cellulose acetate
Authors: Arthanareeswaran Gangasalam , Thanikaivelan Palanisamy
Published: September 2010

In this work, an attempt has been made to separate divalent copper, nickel and zinc ions from aqueous solutions by modified polymeric membranes. Membranes from polysulfone (PSf) and cellulose acetate (CA) were prepared in the absence and presence of the hydrophilic polymer, sulfonated poly ether ether ketone (SPEEK) and additive, polyethyleneglycol (PEG 600), in various compositions. Studies were carried out to find the rejection and permeate flux of Cu(II), Ni(II) and Zn(II) ions using polyethyleneimine (PEI) as the chelating ligand. On increasing concentrations of SPEEK and PEG in PSf and CA casting solution, the rejection of metal ions is decreasing while the permeate flux has an increasing trend. These effects are due to the increased pore formation in the PSf and CA membranes because of the hydrophilic polymer and additive. In general, it was found that CA/SPEEK/PEG blend membranes displayed higher permeate flux and lower rejection compared to PSf/SPEEK/PEG blend membranes at all additive concentrations. It has also been demonstrated that the extent of removal of metal ions depend on the affinity of metal ions to PEI to form macromolecular complexes and the thermodynamic stability of the formed complexes. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Diversity, abundance, and size structure of bivalve assemblages in the Sipsey River, Alabama
Authors: Haag Wendell R. , Warren Melvin L.
Published: September 2010

Patterns of mussel diversity and assemblage structure in the Sipsey River, Alabama, are described. Qualitative data were used to describe river‐wide patterns of diversity. Quantitative data were used to describe the structure of mussel assemblages at several sites based on whole‐substrate sampling that ensured all size classes were detected.

Major human impacts to the stream are limited to apparent effects of coal mining in the headwaters and the impoundment of the lower 9 km of the river by a dam on the Tombigbee River. These impacts resulted in a sharp decline in mussel diversity in the headwaters, and extirpation or decline of populations of several large‐river species in the lower river that were probably dependent on colonization from the Tombigbee River.

Despite localized impacts, mussel assemblages throughout much of the river appear to be mostly intact and self‐sustaining. These assemblages have several attributes that differ substantially from those in more degraded streams: (1) high retention of historical species richness; (2) gradual, longitudinal increase in species richness from upstream to downstream, resulting in distinctive headwater and downstream assemblages; (3) ubiquity of most species within particular river segments; (4) low dominance and high evenness with large populations of many species; and (5) frequent recruitment for most species resulting in occurrence of individuals in many size classes.

Few detailed and demographically unbiased descriptions of relatively intact mussel assemblages exist. We propose that characteristics described in the Sipsey River can be used as a baseline comparison for assessing relative degree of assemblage alteration in other streams and can serve as goals for restoration efforts. Published in 2010 by John Wiley and Sons, Ltd.
Experimental determinations of factors affecting the sink rates of baited hooks to minimize seabird mortality in pelagic longline fisheries
Authors: Robertson Graham , Candy Steven G. , Wienecke Barbara , Lawton Kieran
Published: September 2010

An experiment was conducted in Australia's pelagic longline fishery to establish a scientific basis for the introduction of line weighting to reduce seabird mortality. The experiment examined the effects of different bait species (blue mackerel, yellow‐tail mackerel and squid), bait life status (dead or alive), weight of leaded swivels (60 g, 100 g and 160 g) and leader length (distance between leaded swivel and hooks: 2 m, 3 m and 4 m) on the sink rates of baited hooks from 0–6 m deep.

On average, live bait sank much more slowly than dead bait. The sink rates of individual live bait were highly variable: many were <2 m underwater 18 s after deployment, including some on the heaviest swivels, and some were <10 m deep after 120 s.

Within the dead bait group, all three swivel weights on 3 m and 4 m leaders sank at similar rates. Initial sink rates (e.g. 0–2 m) were 2–3 times slower than final rates (e.g. 4–6 m) for all combinations of swivel weight and leader length. The fastest initial and final sink rates were associated with heavy swivels placed close to hooks.

The results show that (a) compared with dead bait, live bait greatly increases the exposure of baited hooks to seabirds; (b) initial sink rates of dead bait are increased by placing leaded swivels close to hooks and final rates by increasing the weight of the swivels; (c) adding weight to long leaders makes little difference to sink rates; and (d) the small (incremental) changes to swivel weights and leader lengths typically preferred by industry will be difficult to detect at sea and unlikely to substantially reduce seabird mortality.

We suggest that experiments designed to reduce seabird mortality from that associated with 60 g swivels and ∼3.5 m leaders (the preferred option by industry) should aim to expedite the initial sink rates as well as rates to deeper depths. This objective could be achieved by including branch lines with ≥120 g swivels ≤2 m in comparative assessments of the effectiveness of line weighting regimes in reducing seabird mortality. Copyright © 2010 John Wiley & Sons, Ltd.
Gründerzeit‐Mauerwerk unter Erdbebenbelastung — Vergleich zwischen normativen Ansätzen und messtechnischen Ergebnissen
Authors: Zimmermann Thomas , Strauss Alfred
Published: September 2010

Das Bauen mit Mauerwerk beruht auf Erfahrungen aus vielen Jahrhunderten. Obwohl diese Bauweise weltweit Anwendung findet, ist die Kenntnis über das Materialverhalten von Mauerwerk bis heute mit Unsicherheiten behaftet.

Die Bestimmung der Sicherheit dieser Strukturen gegen Erdbeben ist eine komplexe Herausforderung und unter anderem vom Widerstand des Gebäudes, der Einwirkung und konstruktiven Details abhängig. Deshalb sind die seismischen Einwirkungen und das Verhalten von Mauerwerk unter seismischer Belastung von großem Interesse. Für die Bewertung bestehender Altbauten ist das tatsächliche Trag‐ und Verformungsverhalten bedeutsam, damit vorhandene Reserven abgeschätzt werden können. Insbesondere in erdbebengefährdeten Regionen kann durch die Kenntnis des Materialverhaltens eine realitätsnahe Beurteilung der bestehenden Bausubstanz erfolgen. Falls erforderlich, können konstruktiv und wirtschaftlich optimierte Ertüchtigungs‐ und Verstärkungsmaßnahmen zum Einsatz kommen.

Old masonry under seismic loads — Comparison of normative guidelines and measured results. Building with masonry is based on experiences of many centuries. Although, this design is used worldwide, knowledge about the material behaviour of masonry is still afflicted with uncertainties.

The determination of the safety of these structures against earthquakes is a complex challenge. For instance, it depends on the resistance of the structure, the seismic action and on many of uncertain structural details. Therefore the seismic impact itself and the behaviour of masonry under seismic loads are of high inter est. Especially in earthquake prone regions a realistic assess ment of existing buildings may be achieved by having knowledge regarding material behaviour. If needed, constructively and economically optimized retrofit and strengthening methods can be applied.
Flow injection methods for the determination of retinol and α‐tocopherol using lucigenin‐enhanced chemiluminescence
Authors: Asgher Mohammad , Yaqoob Mohammad , Waseem Amir , Nabi Abdul
Published: September 2010

Flow injection (FI) methods are reported to determine retinol and α‐tocopherol based on its enhancement affect of lucigenin chemiluminescence (CL) in alkaline medium. Surfactants including Brij‐35, Triton X‐100, cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate have been reported for the first time to enhance lucigenin CL intensity in the presence of retinol and α‐tocopherol. With Brij‐35, the CL intensity was enhanced by 67% for retinol and 58% for α‐tocopherol. CTAB was found to enhance the CL intensity by 16% for retinol whereas for α‐tocopherol, the CL intensity was quenched up to 95%. Retinol could be determined specifically in the presence of α‐tocopherol using CTAB. The calibration graphs were found to be linear up to 1.43 mg/L (R2 = 0.9985, n = 8) with a detection limit (3s) of 1.43 × 10−3 mg/L for retinol and 2.15 mg/L (R2 = 0.9989; n = 8) with a detection limit (3s) of 4.31 × 10−4 mg/L for α‐tocopherol. An injection throughput of 120/h, and relative standard deviations of 0.9–2.8% (n = 4) were achieved in the concentration range studied. The influence of common ions, excipients in pharmaceutical formulations and related organic compounds on the determination of retinol and α‐tocopherol individually was studied. The proposed methods were applied to determine retinol and α‐tocopherol in pharmaceutical formulations and human blood serum. The results did not differ significantly from the CL method and HPLC reference method at 95% confidence level. Copyright © 2010 John Wiley & Sons, Ltd.
Free Radical Substitution in Aliphatic Compounds. Part IV. The Reaction of Trichloromethyl Radicals with Propane, n‐Butane and Iso‐Butane
Authors: Mcgrath B. P. , Tedder J. M.
Published: September 2010

Mixtures of bromotrichloromethane and the alkanes at circa 60 mm pressure have been irradiated in a Pyrex vessel with light from a medium pressure mercury lamp. The products, which consist solely of chloroform and monobromoalkanes, have been analysed. The reaction has been shown to be a chain process involving attack on the alkane by trichloromethyl radicals which abstract hydrogen atoms from the primary, secondary and tertiary positions in the order 1 : 80 : 2,300 at 190°.kk2/kp2 = 2.68 ± 1.48 exp (3.08 ± 0.46 k. cal/RT); kt2/k82 ≈︁ 5.25 × exp (5.5 k. cal/RT).
Photosensibilisierte C4 Ringsynthesen und die Haupttypen Photosensibilisierter Reaktionen in Lösung
Authors: Schenck Günther O. , Steinmetz Reinhard
Published: September 2010

The C4‐cyclomerization photosensitized by carbonyl compounds is a type of reaction capable of various generalizations. It opens up the synthesis of cyclobutane‐ and cyclobutene‐derivatives often not otherwise amenable.

Among the main types of photosensitization the photosensitized C4‐cyclomerization belongs to the biradical relais‐mechanisms. In some cases the possibility of a mere physical excitation‐transfer from the excited sensitizer to the substrates has been eliminated. Presumably in all cases photosensitized C4‐cyclomerization occurs via homogeneous catalysis involving the production of short‐lived photoadduct‐biradicals composed of excited sensitizer and unsaturated substrate.
Isomérisation Photochimique en Solution du Dibenzoyléthyléne et Dibenzoylstyrène
Authors: Cauzzo Giulio , Mazzucato Ugo , Foffani Antonio
Published: September 2010

On a étudié l'isomérisation photochimique trans‐cis du dibenzoyléthylène et de son dérivé α‐substitué, dibenzoylstyrène à l'aide des spectres d'absorption dans l'ultraviolet.

La réaction a été suivie dans différents milieux en solution concentrée désaérée: l'isomérisation est pratiquement insensible aux changements de solvant; on a observé au contraire une remarquable influence de l'oxygène dissous.

L'effet de sels, négligeable dans un large intervalle de concentrations, devient considérable en présence d'ions paramagnétiques, le rendement quantique décroissant d'une façon presque linéaire avec la concentration du sel. La présence d'iode provoque également un ralentissement de la vitesse d'isomérisation.

Les résultats obtenus permettent de tirer des conclusions sur le mécanisme de la réaction.
La Photolyse de Quelques Composes Cycliques en Milieu Rigide
Authors: Migirdicyan Eva , Leach Sydney
Published: September 2010

Étude de la photolyse en solution rigide d'éthanol à 77°K des composés suivants:

benzène; cyclohexadiène ‐1,3; cyclohexadiène –1,4:

cyclohexadiène –1,3 hydroxyéthyle 5;

cyclohexadiène –1,3 phényle 6 hydroxyéthyle 5;

cyclo‐octatétraène.

Les produits formés sont identifiés par spectroscopie U.V.

Pour tous ces composés on observe la rupture d'une liaison carbone‐carbone du cycle qui, selon le cas étudié, procède soit directement, soit par l'intermédiaire de la formation d'un pont transannulaire.
The influence of pretreatment and enzyme loading on the effectiveness of batch and fed‐batch hydrolysis of corn stover
Authors: Chandra Richard P. , Au‐Yeung Kathy , Chanis Carolina , Roos Alexandra A. , Mabee Warren , Chung Pablo A. , Ghatora Sonia , Saddler Jack N.
Published: September 2010

To try to improve hydrolysis yields at elevated solids loadings, a comparison was made between batch and fed‐batch addition of fresh substrate at the initial and later phases of hydrolysis. Both ethanol (EPCS) and steam‐pretreated corn stover (SPCS) substrates were tested at low (5 FPU) and high (60 FPU) loadings of cellulase per gram of cellulose. The fed‐batch addition of fresh substrate resulted in a slight decrease in hydrolysis yields when compared with the corresponding batch reactions. A 72‐h hydrolysis of the SPCS substrate resulted in a hydrolysis yield of 66% compared with 51% for the EPCS substrate. When the enzyme adsorption and substrate characteristics were assessed during batch and fed‐batch hydrolysis, it appeared that the irreversible binding of cellulases to the more recalcitrant original substrate limited their access to the freshly added substrate. After 72‐h hydrolysis of the SPCS substrate at low enzyme loadings, ∼40–50% of the added cellulases were desorbed into solution, whereas only 20% of the added enzyme was released from the EPCS substrate. Both simultaneous and sequential treatments with xylanases and cellulases resulted in an up to a 20% increase in hydrolysis yields for both substrates at low enzyme loading. Simons' stain measurements indicated that xylanase treatment increased cellulose access, thus facilitating cellulose hydrolysis. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2011