ABSTRACT
A 4-terminal architecture is proposed in which two thin active layers (<100 nm) of PTB7:PC71BM are deposited on a two-sided ITO covered glass substrate. By modeling the electric field distribution inside the multilayer structure and applying an inverse solving problem procedure, we designed an optimal device architecture tailored to extract the highest photocurrent possible. By adopting such a 4-terminal configuration, we numerically demonstrated that even when the two subcells use identical absorber materials, the performance of the 4-terminal device may overcome the performance of the best equivalent single-junction device. In an experimental implementation of such a 4-terminal device, we demonstrate the viability of the approach and find a very good match with the trend of the numerical predictions.
ABSTRACT
An interlaboratory collaborative study to validate a colorimetric phosphatase inhibition assay for quantitative determination of the okadaic acid (OA) toxins group in molluscs, OkaTest, was conducted. Eight test materials, including mussels, scallops, clams, and cockles, were analyzed as blind duplicates. Blank samples and materials containing different OA toxin levels ranging from 98 to 275 microg/kg OA equivalents were included. The study was carried out by a total of 16 laboratories from 11 different countries. Values obtained for repeatability relative standard deviations (RSDr) ranged from 5.4 to 11.2% (mean 7.5%). Reproducibility RSD (RSD(R)) values were between 7.6 and 13.2% (mean 9.9%). The Horwitz ratio (HorRat) values ranged between 0.4 and 0.6. A recovery assay was also carried out using a sample spiked with OA. A mean recovery of 98.0% and an RSD of 14.5% were obtained. The results obtained in this validation study indicate that the colorimetric phosphatase inhibition assay, OkaTest, is suitable for quantitative determination of the OA toxins group. OkaTest could be used as a test that is complementary to the reference method for monitoring the OA toxins group.
Subject(s)
Colorimetry/methods , Enzyme Inhibitors/analysis , Okadaic Acid/analysis , Phosphoprotein Phosphatases/antagonists & inhibitors , Reproducibility of ResultsABSTRACT
This combined experimental (STM, XPS) and molecular dynamics simulation study highlights the complex and subtle interplay of solvent effects and surface interactions on the 2-D self-assembly pattern of a Schiff-base macrocycle containing catechol moieties at the liquid-solid interface. STM imaging reveals a hexagonal ordering of the macrocycles at the n-tetradecane/Au(111) interface, compatible with a desorption of the lateral chains of the macrocycle. Interestingly, all the triangular-shaped macrocycles are oriented in the same direction, avoiding a close-packed structure. XPS experiments indicate the presence of a strong macrocycle-surface interaction. Also, MD simulations reveal substantial solvent effects. In particular, we find that co-adsorption of solvent molecules with the macrocycles induces desorption of lateral chains, and the solvent molecules act as spacers stabilizing the open self-assembly pattern.
ABSTRACT
A Fontan completion with a hybrid approach was performed on a 27-month-old girl with a univentricular heart. A large covered stent was placed between the inferior vena cava and the cavopulmonary anastomosis through a pericardial patch in the intracardiac fenestrated tunnel, circumventing the need for an occluder device for baffle closure. The child's progress has been good and she displays normal growth and acceptable clinical, ultrasonographic, and laboratory results.
Subject(s)
Fontan Procedure/methods , Heart Defects, Congenital/surgery , Child, Preschool , Female , Heart Bypass, Right , Humans , Stents , Vena Cava, Inferior/surgeryABSTRACT
In recent years, there has been an increase in the production of shellfish and in global demand for seafood as nutritious and healthy food. Unfortunately, a significant number of incidences of shellfish poisoning occur worldwide, and microalgae that produce phycotoxins are responsible for most of these. Phycotoxins include several groups of small to medium sized natural products with molecular masses ranging from 300 to over 3000 Da. Cyclic imines (CIs) are a recently discovered group of marine biotoxins characterized by their fast acting toxicity, inducing a characteristic rapid death in the intraperitoneal mouse bioassay. These toxins are macrocyclic compounds with imine (carbon-nitrogen double bond) and spiro-linked ether moieties. They are grouped together due to the imino group functioning as their common pharmacore and due to the similarities in their intraperitoneal toxicity in mice. Spirolides (SPXs) are the largest group of CIs cyclic imines that together with gymnodimines (GYMs) are best characterized. Although the amount of cyclic imines in shellfish is not regulated and these substances have not been categorically linked to human intoxication, they trigger high intraperitoneal toxicity in rodents. In this review, the corresponding chemical structures of each member of the CIs and their derivatives are reviewed as well as all the data accumulated on their mechanism of action at cellular level.
Subject(s)
Heterocyclic Compounds, 3-Ring/metabolism , Hydrocarbons, Cyclic/metabolism , Imines/metabolism , Marine Toxins/metabolism , Microalgae/chemistry , Pyrans/metabolism , Shellfish Poisoning/metabolism , Shellfish/toxicity , Spiro Compounds/metabolism , Animals , Binding Sites , Biological Assay , Cell Survival/drug effects , Food Contamination , Heterocyclic Compounds, 3-Ring/chemistry , Heterocyclic Compounds, 3-Ring/toxicity , Humans , Hydrocarbons, Cyclic/chemistry , Hydrocarbons, Cyclic/toxicity , Imines/chemistry , Imines/toxicity , Injections, Intraperitoneal , Marine Toxins/chemistry , Marine Toxins/toxicity , Mice , Muscarinic Antagonists/chemistry , Muscarinic Antagonists/metabolism , Muscarinic Antagonists/toxicity , Nicotinic Antagonists/chemistry , Nicotinic Antagonists/metabolism , Nicotinic Antagonists/toxicity , Protein Binding , Pyrans/chemistry , Pyrans/toxicity , Receptors, Muscarinic/metabolism , Receptors, Nicotinic/metabolism , Shellfish Poisoning/physiopathology , Spiro Compounds/chemistry , Spiro Compounds/toxicity , Structure-Activity RelationshipABSTRACT
Miniaturized combined arrays of three different pH indicators allowing for sensitive, robust and broad-range acidity detection are prepared by parallel dip-pen nanolithography, which proves the potential of this technique to fabricate multiplexed platforms at the micro- and nanoscale that can act as sensors.
Subject(s)
Hydrogen-Ion Concentration , Microarray Analysis/instrumentation , Microtechnology/methods , Indicators and Reagents , Sensitivity and SpecificityABSTRACT
Two different soft lithographic techniques (LCW and microCP) have been successfully used for the structuration of fluorescent pH-responsive molecules on surface. The molecules of choice, fluorescein (1) and a new catechol derivative (2), exhibit several protonation states with distinct emission properties over a large acid-base range. This allowed us to fabricate fluorescent arrays that respond over a large pH-window.
Subject(s)
Fluorescent Dyes/chemistry , Graphite/chemistry , Hydrogen-Ion Concentration , Nanostructures/chemistry , Nanostructures/ultrastructure , Spectrometry, Fluorescence , Surface PropertiesABSTRACT
In this letter, we report on the development of a surface molecular sensor for the detection of acidity. Lithographically controlled wetting deposition has been applied to form the nanostructure of a new fluorescent compound with three protonation states featuring different optical properties on a glass substrate. Atomic force microscopy demonstrates the functionalization of the surface with ordered arrays of the sensor molecules. The fluorescence properties of the resulting nanopattern at different pH values have been investigated by confocal fluorescene microsopy, thus revealing the fast, sensitive, reversible response of the prepared nanosensor to gas flows of varying acidity.
ABSTRACT
Hemos empleado el óxido nítrico en un paciente pediátrico con cardiopatía congénita de tipo canal atrio-ventricular completo con hipertensión arterial pulmonar severa, cianosis y desnutrición avanzada. Este ha sido llevado al laboratorio de cateterismo cardiaco para valorar el estado de los vasos pulmonares y precisar el daño vascular pulmonar, por lo cual se realizan pruebas farmacológicas con aire ambiente, oxígeno al 100 por ciento y óxido nítrico. En el estudio se demuestra el efecto vasodilatador importante del óxido nítrico: la presión de arteria pulmonar y resistencias arteriolares pulmonares descienden en forma notable de 8.75 U Wood/m² a 1.32 U Wood/m², el gasto pulmonar total aumenta, y el gradiente entre la presión en cuña y la del atrio izquierdo desparece. Por eso la hipertensión arterial pulmonar severa es reversible si el defecto congénito es corregido quirúrgicamente
Subject(s)
Humans , Male , Infant , Heart Defects, Congenital/therapy , Down Syndrome , Hemoglobins/analysis , Hypertension, Pulmonary/etiology , Nitric Oxide/administration & dosage , Nitric Oxide/pharmacokinetics , Nitric Oxide/metabolism , Nitric Oxide/therapeutic use , Pulmonary Gas Exchange/drug effects , RheologyABSTRACT
Se reporta un lactante de 38 días de vida, con 3.2 kg de peso y portador de síndrome de Down, soplo cardiaco y taquipnea. En el ecocardiograma Doppler color se encuentran persistencia del conducto arterioso e hipertensión arterial pulmonar. Se realizó cateterismo cardiaco que confirmó conducto arterioso permeable del tipo A-2 de 1.5 mm en su diámetro más angosto, con Qp/Qs de 1.8 e hipertensión arterial pulmonar. Se colocó espiral metálica de 5 cm de largo x 5 mm de diámetro por vía anterógrada a través de vena femoral, con oclusión completa del conducto y desaparición de hiperflujo e hipertensión arterial pulmonar. Concluimos que, en lactantes pequeños como en este caso, el uso de espiral metálica es una buena alternativa para el cierre del ducto arterioso
Subject(s)
Humans , Male , Child, Preschool , Cardiac Catheterization , Ductus Arteriosus, Patent/diagnosis , Ductus Arteriosus, Patent/therapy , Embolization, Therapeutic/instrumentation , Embolization, Therapeutic/methods , Down Syndrome/complicationsABSTRACT
Las lesiones térmicas intraoperatórias son un riesgo y una realidad que han ido incrementándose cada vez más. Su ocorrencia y el fundamento jurídico de la responsabilidad y de la culpabilidad son analizados en esta presentación. Se conclcuye que médicos y establecimientos asistenciales no pueden eludir esa responsabilidad y que con ciertos cuidados en el accionar médico quirúrgico, con la supervisión del equipo y del personal auxiliar y con el adecuado equipamiento y mantenimiendo del área quirúrgica, es factible evitar estos accidentes (AU)
Subject(s)
Humans , Intraoperative Complications , Burns, Electric , Burns, Chemical , Professional Practice , General Surgery , Social ResponsibilityABSTRACT
Las lesiones térmicas intraoperatórias son un riesgo y una realidad que han ido incrementándose cada vez más. Su ocorrencia y el fundamento jurídico de la responsabilidad y de la culpabilidad son analizados en esta presentación. Se conclcuye que médicos y establecimientos asistenciales no pueden eludir esa responsabilidad y que con ciertos cuidados en el accionar médico quirúrgico, con la supervisión del equipo y del personal auxiliar y con el adecuado equipamiento y mantenimiendo del área quirúrgica, es factible evitar estos accidentes
