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Dentro del panteón de las grandes series de televisión de las últimas décadas, sin duda The Wire (D. Simon & E. Burns, HBO, 2002-2006), ocupa un lugar destacado para la crítica y el público. The Wire, disfrazada de thriller policiaco, es un relato seriado que destaca por una estructura cíclica, unos arquetipos trágicos y una mirada coral que la diferencian del resto del contenido televisivo actual. Tres características (coralidad, tragedia y elementos cíclicos) que conforman la esencia del teatro griego. Y es que en cuanto nos detenemos a analizar The Wire vemos hasta qué punto los personajes y tramas de una de las series más prestigiosas de la historia, deben su esencia y su desarrollo a la cosmogonía y la mitología griega, soporte y alimento de toda nuestra cultura.

El objetivo de la presente investigación es desarrollar una herramienta de base tecnológica para el mejoramiento de la gestión y operación logística en las principales empresas distribuidoras de productos de consumo masivo de Ibagué. En particular, la investigación busca contribuir al mejoramiento de las principales decisiones del manejo de los inventarios, específicamente en la planeación de compras de los pedidos en las distribuidoras. Para el desarrollo de la investigación se establecen dos etapas. La primera denominada preliminar comprenderá la documentación problemática existente frente a la gestión de inventarios, al igual que los referentes teóricos para la fundamentación del desarrollo frente a la logística en sus diferentes enfoques para el sector empresarial. Por otra parte, la segunda etapa de desarrollo se estructurará en tres fases: Fase 1. Diagnóstico y caracterización en las principales empresas distribuidoras de productos de consumo masivo en Ibagué. Fase 2. Formular estrategias para identificar y seleccionar políticas de control de inventario. Fase 3. Generar una herramienta que permita establecer un modelo para mejorar la toma de decisiones. La administración de inventarios responde los problemas que surgen en las organizaciones sobre comprar y mantener existencias, formulando y respondiendo inquietudes del ¿qué?, ¿dónde?, ¿cuándo? y ¿cuánto? comprar, teniendo como principal objetivo la disminución de costos a través de la implementación de herramientas computacionales con diversos niveles de servicio que permitan determinar la situación más rentable (Ballou, 2004).

Altres ajuts: acords transformatius de la UAB A warning microanalyzer for the rapid monitoring of different heavy metals in water using Carbon Dots (CDs) as selective optical reagents is presented. The synthesized CDs have different surface functionalization and exhibit selective fluorescence quenching by heavy metal ions, that combined with the use of microfluidics, provide sensitivity, ease of automation and reproducibility to the method. Moreover, they present maximum excitation wavelengths around 350 nm, allowing multiparametric analysis with a single light source. Although quantum yields range from 16 % to 78 % depending on the type of CDs, enough sensitivity is achieved for each heavy metal using the same measurement conditions of the optical detection system (lock-in modulating frequency, signal amplitude and measurement frequency). The microanalyzer is composed of a Cyclic Olefin Copolymer (COC) analytical microsystem, a flow management system, and a miniaturized customized optical detection system. In this paper, we demonstrate that our proposed system can be used as a toxicity control system by selectively measuring five different heavy metal ions (Co, Cu, Hg, Ni, and Pb) with detection limits ranging from 2 to 12 ppb. Spiked tap water samples were analyzed, giving recoveries from 98 % to 134 %. Polluted samples containing four of the five heavy metal ions studied (Co, Cu, Ni, and Pb) were also analyzed with no significant differences observed between both methods, the proposed microanalyzer and the reference method (ICP-OES).

Altres ajuts: acords transformatius de la UAB Some inborn errors of metabolism and other diseases can result in increasing blood ammonium (hyperammonemia episodes), which can cause serious neurological complications in patients or even death. Early diagnosis, follow up and treatment are essential to minimize irreversible damages in brain. Currently, adequate analytical instrumentation for the necessary ammonium bedside determination is not available in all health centers but only in clinical laboratories of reference hospitals. We therefore have developed a low cost and portable potentiometric Point-of-Care microanalyzer (POC) to address this problem. It consists of a cyclic olefin copolymer-based microanalyzer, the size of a credit card and working in continuous flow, which integrates microfluidics, a gas-diffusion module and a potentiometric detection system. The analytical features achieved are a linear range from 30 to 1000 μmol L NH , a detection limit of 18 μmol L NH and a required sample volume of 100 μL, which comply with the medical requirements. Plasma and blood samples are analyzed with no significant differences observed between ammonium concentrations obtained with both the proposed microanalyzer and the reference method. This demonstrates the value of the developed POC for bedside clinical applications.

El Banco de la República (BanRep) genera información para la toma de decisiones, la rendición de cuentas y la difusión al público. En particular, el Reporte de Mercados Financieros está enmarcado dentro del principio de difusión al público y contribuye a cumplir con el servicio que presta el Banco de ofrecer información e investigación económica de calidad.

Proponemos nuevos modelos para el efecto de “El Nino Southern Oscillation”, ENSO, sobre los precios de los alimentos en Colombia. Estudiamos el efecto del “Oceanic Nino Index”, ONI, la medida de ENSO preferida, y de las precipitaciones locales sobre los precios de los alimentos perecederos. Estos modelos surgen de hechos estilizados conocidos, los cuales resumimos en este escrito, y admiten representaciones tiempo-variantes espacio-estado, de las que derivamos las reglas optimas de pronostico. Encontramos que una funcion de transferencia simple, condicional a la intensidad de ENSO, es suficiente para explicar estas relaciones. En adicion al bien conocido hecho que la Nina tiene un efecto distinto al del Nino sobre los precios de los alimentos, tambien hallamos que el efecto de ENSO cambia con su intensidad. Reconocer que el ONI es un indicador imperfecto de las condiciones climaticas locales mejora el ajuste de nuestro modelo, lo cual se refleja en sus pronosticos. El modelo para la precipitacion, sin embargo, no necesita de este recurso. Tambien surgen ganancias en eficiencia debido al modelamiento de la heterocedasticidad. Finalmente, estos modelos pueden servir para entender el efecto de ENSO en otras variables como el PIB.

El Banco de la República genera información para la toma de decisiones, la rendición de cuentas y la difusión al público. En particular, el Reporte de Mercados Financieros está enmarcado dentro del principio de difusión al público y contribuye a cumplir con el servicio que presta el Banco de ofrecer información e investigación económica de calidad.

Innovation in products and processes, traceability, food security and quality control are inherent challenges in agri-food sector. Trends in wine production are focused on obtaining natural wines with less chemical intervention. Following this goal, a low cost miniaturized, easy-to-use and highly automated microanalyzer to monitor total potassium in winemaking processes is presented. The microsystem monolithically integrates microfluidics as well as a potentiometric detection system and does not require any sample pretreatment. The analytical features provided are a linear range from 250 to 4000 mg L-1 K+, covering all the concentrations expected in must and wine samples, a detection limit of 75 ± 12 mg L-1 K+, and an adequate reproducibility and repeatability. Sample throughput is calculated at 20 h−1 with a waste volume generation lower than 4 mL per analysis. The microsystem lifetime is at least 4 months. Different wine and grape juice samples have been analyzed reaching outstanding results.

El comportamiento de los precios de los alimentos en Colombia ha sido un factor que inquieta a la autoridad monetaria por su volatilidad, alta ponderacion en la canasta de IPC y en ocasiones recurrentes altos niveles debido a su reaccion a choques de oferta como el clima, lo cual dificulta la tarea de estabilizar la inflacion alrededor de la meta. De lo anterior, se desprende la necesidad de tener pronosticos insesgados y mas oportunos de los cambios en el precio de los alimentos en el corto plazo. En este documento se desarrolla una metodologia que aprovecha la informacion disponible con alta frecuencia de precios y abastecimiento de alimentos y permite combinar informacion observada en varias frecuencias para generar pronosticos alternativos de la variacion de los precios de los alimentos y sus diferentes componentes. Los resultados encontrados indican que los modelos propuestos de frecuencias mixtas, producen mejores pronosticos que los tradicionales que utilizan solamente informacion de precios del Sistema de Informacion de Precios del Sector Agropecuario (SIPSA-DANE).

En este documento se presenta una caracterizacion de los fenomenos meteorologicos de El Nino y La Nina, y una descripcion de sus principales efectos sobre la inflacion en Colombia. Estos episodios climaticos se vienen presentando desde hace siglos en el territorio nacional, generando cambios en el nivel de temperaturas y precipitaciones en la mayor parte del territorio colombiano, sin que hayan tenido historicamente un patron regular de ocurrencia y de intensidad. Durante la ocurrencia de El Nino se destaca el efecto negativo sobre el sector agropecuario, que impacta fuertemente los precios de la canasta de alimentos y en menor medida la inflacion anual al consumidor. A pesar de la no sistematicidad en la ocurrencia de estos eventos climaticos, la inflacion de alimentos, la inflacion al consumidor y el precio relativo de los alimentos muestran comportamientos alcistas durante la ocurrencia de El Nino. Durante La Nina se presenta una disminucion de los precios al consumidor. El precio relativo de los alimentos muestra disminuciones al concluir cualquiera de los dos fenomenos.

In this work, the influence of laser ablation and lamination parameters in the fabrication of embedded microstructures using Low Temperature Co-Fired Ceramics, have been studied. First, the influence of laser ablation parameters in the dimensions of fabricated microchannels in Low Temperature Co-Fired Ceramics substrates was characterized and strategies for tailoring the microchannels aspect ratios are described. The influence of lamination conditions on the fabrication of monolithically embedded microstructures is presented. Thereafter, a ceramic microfluidic platform, was constructed using a multilayer approach. The ceramic microfluidic platforms incorporate three independent inlet channels and a microfluidic chamber with an monolithically integrated transparent optical windows. The construction procedure used ensures monolithic ceramic devices with homogeneous surface chemistry as well as homogeneous physical properties. Fluorescence dyes were used in order to characterize the hydrodynamic focusing as a function of flow rate ratio of the microfluidic chamber inlets. The results obtained open the possibility of studying chemical process, in static or flow conditions using fluorescence imaging, within the traditional fields of LTCC technology, such as high-temperature or organic solvents applications, while using a simple fabrication procedure suitable for low cost mass production.

meso-Bromosubstituted indodicarbocyanine dyes produce dimeric molecules, together with the debrominated species, under acid catalysis. The relationship between the dimerization and hydrodebromination routes depends on the aryl substitution of the dyes. A possible reaction mechanism is also proposed.

The analysis of soluble reactive phosphate (SRP) in water is key to control water quality. In order to continuous monitor orthophosphate content in water during treatment processes and in the effluents of wastewater treatment plants, conventional procedures, usually performed in a laboratory, must be adapted. This means pursuing efforts on miniaturizing systems to operate in situ and automating analytical methods to work on-line. The design, construction and evaluation of an automatic and low cost cyclic olefin copolymer (COC)-based spectrophotometric microanalyzer, capable of operating in unattended conditions, is presented to monitor soluble reactive phosphorous, as orthophosphate ion, in wastewater samples coming from sewage treatment plants. The microsystem, constructed by CNC micromilling and using a multilayer approach, integrates microfluidics to carry out the phosphomolybdenum blue (PMB) reaction and an optical flow-cell for the spectrophotometric orthophosphate determination in a single polymeric substrate smaller than a credit card. It is connected to a compact optical detection system composed by a LED emitting at 660 nm and a PIN-photodiode, both integrated in a PCB. Flow management is automatically performed by programmed microvalves and micropumps, which control autocalibration processes and allow unattended operation. Analytical features after the optimization of the microfluidic platform and the chemical and the hydrodynamic variables, were a linear range from 0.09 to 32 mg L−1 P and a detection limit of 0.03 mg L−1 P with a sampling rate of 24 samples h−1, demonstrating the microanalyzer suitability for SRP monitoring in water. Moreover, real samples were analyzed obtaining promising results.

The design, construction and evaluation of a low cost, cyclic olefin copolymer (COC)-based continuous flow microanalyzer, with optical detection, to monitor carbon dioxide in bottled wines and beers as well as in fermentation processes, is presented. The microsystem, constructed by computer numerically controlled (CNC) micromilling and using a multilayer approach, integrates microfluidics, gas-diffusion module and an optical flow-cell in a single polymeric substrate. Its size is slightly bigger than a credit card, exactly 45 × 60 × 4 mm in the microfluidic and diffusion module zone and 22.5 × 40 × 3 mm in the flow-cell zone. The gas-diffusion module is based on a hydrophobic polyvinylidene fluoride (PVDF) membrane, which allows the transfer of the carbon dioxide present in the sample to a bromothymol blue (BTB) pH-sensitive acceptor solution, where the color change is measured optically. The detection system consisted of a LED with an emission peak at 607 nm and a photodiode integrated in a printed circuit board (PCB). The obtained analytical features after the optimization of the microfluidic platform and hydrodynamic variables are a linear range from 255 to 10000 mg L−1 of CO2 and a detection limit of 83 mg L−1 with a sampling rate of 30 samples h−1.

The progress made in recent years in the area of micro total analysis system (μ-TAS) has allowed the development of analytical tools for determination and measurement of elements and compounds that previously required bench laboratory equipment for such purposes. μ-TAS provides a high degree of sensitivity and they are simple and affordable. This work details a process by which classical colorimetric methodologies used in analysis have been adapted from discontinuous to continuous flow systems, for determination of cobalt in aqueous solutions in real time. The purpose of this adaptation is the subsequent system miniaturization using low temperature co-fired ceramics (LTCC). The adapted methodology for the colorimetric determination of cobalt uses 3-Hydroxy-4-nitroso-2,7-naphtalene disulfonic acid disodium salt or nitroso-R salt (NRS) as the main reagent, in an environment of acetate and sodium citrate which favors the reaction. The carrier solution is prepared with sulfuric acid. The system encompasses a microfluidic structure in LTCC, a peristaltic pump to maintain the continuous flow, a six-way valve for sample injection, and an issuer of light of 540 nm based on a multiled. Using the integrated circuit TCS3414, the signal is sent to the computer wirelessly through zigbee protocol, and at the end a LabVIEW-based application shows the absorbance for a range of concentrations between 0.5 and 10 mg/L.

A boron trifluoride–methanol complex demonstrated remarkable deprotection selectivity against commonly used amino-protecting groups in the deacetylation of acetanilides and high sensitivity to the steric hindrance of substrates. The scope and limitations of the reaction were explored.

The successful integration of sample pretreatment stages, sensors, actuators and electronics in microfluidic devices enables the attainment of complete micro total analysis systems, also known as lab-on-a-chip devices. In this work, we present a novel monolithic autonomous microanalyzer that integrates microfluidics, electronics, a highly sensitive photometric detection system and a sample pretreatment stage consisting on an embedded microcolumn, all in the same device, for on-line determination of relevant environmental parameters. The microcolumn can be filled/emptied with any resin or powder substrate whenever required, paving the way for its application to several analytical processes: separation, pre-concentration or ionic-exchange. To promote its autonomous operation, avoiding issues caused by bubbles in photometric detection systems, an efficient monolithic bubble removal structure was also integrated. To demonstrate its feasibility, the microanalyzer was successfully used to determine nitrate and nitrite in continuous flow conditions, providing real time and continuous information.

Ultrasmooth gold/silver/gold trilayer nanostructured plasmonic sensors were obtained using commercial Blu-ray optical discs as nanoslits-based flexible polymer substrates. A thin gold film was used as an adhesion and nucleation layer to improve the chemical stability and reduce the surface roughness of the overlying silver film, without increasing ohmic plasmon losses. The structures were physically and optically characterized and compared with nanostructures of single gold layer. Ultrasmooth and chemically stable trilayer nanostructures with a surface roughness, Departament d'Universitats, Recerca i Societat de la Informació, Grant/Award Number: 2014 SGR 624; Ministerio de Economía y Competitividad, Grant/Award Number: SEV-2013-0295; Programa Estatal de investigación, desarrollo e innovación orientada a los Retos de la Sociedad, Grant/Award Number: TEC2016-78515-R; Spanish Ministry of Economy, Industry and Competitiveness (MINECO, Grant/Award Number: SEV2013-0295; CERCA programme/Generalitat de Catalunya; Departament d'Universitats, Recerca i Societat de la Informació de la Generalitat de Catalunya, Grant/Award Number: 2014 SGR 624; PreDICT project, Grant/Award Number: TEC2016-78515-R; CONACYT, Grant/Award Number: 225362

Introduction: All over the world 5.4 million people die due to tobacco related diseases per year. Considering that teenagers are highly impressionable by media in tobacco consumption, they constitute the population of interest in order to diminish the use of tobacco and the morbidity associated with its use. Objective: To identify factors associated at the beginning of tobacco consumption. Methodology: Descriptive cross-sectional study using a poll created from a questionnaire on tobacco by Center of Disease Control and Prevention, with a sample of smokers, over 18, selected in the most popular smoking areas at Universidad Javeriana, Bogota – Colombia. Results: The most frequent factors related to the beginning of tobacco consumption were: Peer pressure (34.6%), curiosity (24.7%) and stress (17.6%). The average starting smoking age was 14.3 (±1.9). Conclusion: The low capacity of opposing social pressure at parties and recreational events showed as the most important factor at the beginning of a smoking habit.

A novel and versatile optical reader for microfluidic platforms is presented. The reader includes a modular insertion port based on the lock and key concept for reproducible alignment with a miniaturized optical detection system comprising an interchangeable light emitting diode (LED) and a photodiode. The modular nature of the insertion port allows the use of microfluidic platforms in variable shapes and fluidic configurations. Three different analytical methodologies based on absorbance or fluorescence measurements were used to demonstrate the flexibility and reproducibility of the proposed experimental setup.

This work is focused on the design and implementation of a microsystem for continuous colorimetric determination of cobalt in aqueous solutions in real time. The main goal is the colorimetric determination of cobalt by adapting colorimetric methodologies used in discontinuous analysis systems to a continuous flow system and its subsequent miniaturization using the LTCC (Low Temperature Co-fired Ceramics) technology. The measure absorbance was recorded using an optical detection system based on a LED (Light Emitting Diode) with a wavelength of 540 nm.

Assisted reproductive technology (ART) can benefit from the features of microfluidic technologies, such as the automation of time-consuming labor-intensive procedures, the possibility to mimic in vivo environments, and the miniaturization of the required equipment. To date, most of the proposed approaches are based on polydimethylsiloxane (PDMS) as platform substrate material due to its widespread use in academia, despite certain disadvantages, such as the elevated cost of mass production. Herein, we present a rapid fabrication process for a cyclic olefin copolymer (COC) monolithic microfluidic device combining hot embossing—using a low-temperature cofired ceramic (LTCC) master—and micromilling. The microfluidic device was suitable for trapping and maturation of bovine oocytes, which were further studied to determine their ability to be fertilized. Furthermore, another COC microfluidic device was fabricated to store sperm and assess its quality parameters over time. The study herein presented demonstrates a good biocompatibility of the COC when working with gametes, and it exhibits certain advantages, such as the nonabsorption of small molecules, gas impermeability, and low fabrication costs, all at the prototyping and mass production scale, thus taking a step further toward fully automated microfluidic devices in ART.

The construction and evaluation of a Cyclic Olefin Copolymer (COC)-based continuous flow potentiometric microanalyzer to simultaneously monitor potassium, chloride and nitrate ions in samples from an on-board water recycling process expected to be installed in future manned space missions is presented. The main goals accomplished in this work address the specific required characteristics for a miniaturized on-line monitoring system to control water quality in such missions. To begin with, the integration of three ion-selective electrodes (ISEs) and a reference electrode in a compact microfluidic platform that incorporates a simple automatic autocalibration process allows obtaining information about the concentration of the three ions with optimal analytical response characteristics, but moreover with low reagents consumption and therefore with few waste generation, which is critical for this specific application. By a simple signal processing (signal removal) the chloride ion interference on the nitrate electrode response can be eliminated. Furthermore, all fluidics management is performed by computer-controlled microvalves and micropumps, so no manual intervention of the crew is necessary. The analytical features provided by the microsystem after the optimization process were a linear range from 6.3 to 630 mg L−1 and a detection limit of 0.51 mg L−1 for the potassium electrode, a linear range from 10 to 1000 mg L−1 and a detection limit of 1.58 mg L−1 for the chloride electrode and a linear range from 10 to 1000 mg L−1 and a detection limit of 3.37 mg L−1 for the nitrate electrode with a reproducibility (RSD) of 4%, 2% and 3% respectively. Sample throughput was 12 h−1 with a reagent consumptions lower than 2 mL per analysis.

The synthesis of a set of open-chain bis-aminosubstituted cyanine dyes as well as others with cyclic fragments in the polymethine chain is presented. These dyes are suitable for the development of polymeric compositions with variable optical characteristics as they can be covalently incorporated into the polymer.

All-ceramic microfluidic platforms with integrated optical microflow cells, fabricated using the low-temperature co-fired ceramics (LTCC) technology, are presented. The fabrication procedure described allows the construction of hermetically sealed monolithic microfluidic platforms, with homogeneous surface chemistry and physical properties. Therefore, the presented procedure eliminates the problems related to properties mismatch of the different construction materials used up to now to integrate transparent windows in the ceramic platforms. LTCC sheets, used as optical windows, were optically characterized in terms of transmittance according to their thickness in the UV–Vis–NIR regions. The influence of optical microflow cells parameters, such as optical path length, diameter, and window thickness, on sensitivity and detection limit, were investigated using the colorimetric complex [Fe(phen)3]2+ formed between Fe(II) and 1,10-phenanthroline. Detection limit as low as 8 ppb of Fe(II) was obtained. The results open the possibility of using optical detection within the traditional application fields of LTCC technology, such as high-temperature or organic solvents applications, while using a simple fabrication procedure suitable for low-cost mass production.

An optical microfluidic system based on the use of modified gold nanoparticles for monitoring Hg(II) is presented. The system is based on the specific recognition of the heavy metal by a new synthesized ionophore based on a modified thiourea, which is attached to the gold nanoparticles. This interaction generates a change on the gold Surface Plasmon Resonance (SPR) band. The sensitivity and selectivity of the procedure is firstly studied in batch. The obtained results demonstrate the mercury selective response over the different tested ions that can be found in environmental water samples. Due to the remarkable unusual rapid signal change observed during the interaction of the metal and the modified gold nanoparticles, the reaction can be easily performed in a microfluidic system. Results obtained by using the microfluidic system revealed improved analytical features compared to batch experiments such as a lower detection limit (11 ppb), higher sensitivity and faster analysis time, all this with an easy and automated procedure. Therefore, the approach has shown great potential for designing low cost instrumentation for automatic in-field discrete or continuous measurements of Hg(II).

The present paper describes the use of a microfluidic system to synthesize carbon dots (Cdots) and their use as optical pH sensors. The synthesis is based on the thermal decomposition of ascorbic acid in dimethyl sulfoxide. The proposed microsystem is composed of a fluidic and a thermal platform, which enable proper control of synthesis variables. Uniform and monodispersed 3.3 nm-sized Cdots have been synthesized, the optical characterization of which showed their down/upconversion luminescence and colorimetric properties. The obtained Cdots have been used for pH detection with down and upconverison fluorescent properties as excitation sources. The naked eye or a photographic digital camera has also been implemented as detection systems with the hue parameter showing a linear pH range from 3.5 to 10.2. On the other hand, experiments on the cytotoxicity and permeability of the Cdots on human embryonic kidney cells revealed their adsorption on cells without causing any impact on the cellular morphology. This work was supported by Projects SGR 2009-0323 from Catalonia Government and P10-FQM-5974 from the Junta de Andalucía (Spain). These projects were partially supported by European Regional Development Funds (ERDF). Our thanks to “Reincorporacion de Doctores UGR” programs and Greib startup

This work describes the development of a fully integrated Low Temperature Co-fired Ceramic (LTCC) microreactor for the synthesis of carbon dots (CDots). The microreactor integrates fluidics, a heating resistor and an optical window for fluorescence imaging of the reaction progress in a monolithic, all ceramic device, ensuring homogeneous surface chemistry and physical properties. A pool of different CDots was synthesized at high temperature and pressure using a hydrothermal method, demonstrating the robustness of the microreactor. The synthesis was monitored by following the photoluminescence of the produced CDots, and the reaction conditions were optimized according to their Quantum Yield (QY) and the flow pattern inside the microchannel. The obtained CDots exhibited blue photoluminescence upon irradiation with UV light with QYs of up to 0.77. The CDots were screened as metal nanoprobes and bioimaging contrast agents.

The construction and evaluation of a Low Temperature Co-fired Ceramics (LTCC)-based continuous flow potentiometric microanalyzer prototype to simultaneously monitor the presence of two ions (potassium and nitrate) in samples from the water recycling process for future manned space missions is presented. The microsystem integrates microfluidics and the detection system in a single substrate and it is smaller than a credit card. The detection system is based on two ion-selective electrodes (ISEs), which are built using all-solid state nitrate and potassium polymeric membranes, and a screen-printed Ag/AgCl reference electrode. The obtained analytical features after the optimization of the microfluidic design and hydrodynamics are a linear range from 10 to 1000 mg L−1 and from 1.9 to 155 mg L−1 and a detection limit of 9.56 mg L−1 and 0.81 mg L−1 for nitrate and potassium ions respectively.

La función administrativa de protección del patrimonio arqueológico con frecuencia conlleva pesadas cargas y un importante quebranto económico para los propietarios inmobiliarios. Tales cargas se traducen en concretas obligaciones de hacer y de soportar, que varían en función de la naturaleza del inmueble afectado y de los supuestos concurrentes. Así, la realización de obras en terrenos que gozan de una declaración formal de valor cultural, la constatación o presunción de restos arqueológicos o su hallazgo casual determinan en diferente medida la imposición de aquellas obligaciones arqueológicas. Ante la falta de una regulación sistemática sobre la materia en la legislación estatal y autonómica de patrimonio cultural, este trabajo analiza todas esas cargas arqueológicas y examina los diversos conceptos indemnizables y los mecanismos previstos para compensar el perjuicio sufrido.

A boron trifluoride–methanol complex demonstrated remarkable deprotection selectivity against commonly used amino-protecting groups in the deacetylation of acetanilides and high sensitivity to the steric hindrance of substrates. The scope and limitations of the reaction were explored.

Monitoring organic environmental contaminants is of crucial importance to ensure public health. This requires simple, portable and robust devices to carry out on-site analysis. For this purpose, a low-temperature co-fired ceramics (LTCC) microfluidic potentiometric device (LTCC/ POT) was developed for the first time for an organic compound: sulfamethoxazole (SMX). Sensory materials relied on newly designed plastic antibodies. Sol–gel, self-assembling monolayer and molecular-imprinting techniques were merged for this purpose. Silica beads were amine-modified and linked to SMX via glutaraldehyde modification. Condensation polymerization was conducted around SMX to fill the vacant spaces. SMX was removed after, leaving behind imprinted sites of complementary shape. The obtained particles were used as ionophores in plasticized PVC membranes. The most suitable membrane composition was selected in steady-state assays. Its suitability to flow analysis was verified in flow-injection studies with regular tubular electrodes. The LTCC/ POT device integrated a bidimensional mixer, an embedded reference electrode based on Ag/AgCl and an Ag-based contact screen-printed under a micromachined cavity of 600 m depth. The sensing membranes were deposited over this contact and acted as indicating electrodes. Under optimum conditions, the SMX sensor displayed slopes of about −58.7 mV/decade in a range from 12.7 to 250 g/mL, providing a detection limit of 3.85 g/mL and a sampling throughput of 36 samples/h with a reagent consumption of 3.3 mL per sample. The system was adjusted later to multiple analyte detection by including a second potentiomet-ric cell on the LTCC/ POT device. No additional reference electrode was required. This concept was applied to Trimethoprim (TMP), always administered concomitantly with sulphonamide drugs, and tested in fish-farming waters. The biparametric microanalyzer displayed Nernstian behaviour, with aver-age slopes −54.7 (SMX) and +57.8 (TMP) mV/ decade. To demonstrate the microanalyzer capabilities for real applications, it was successfully applied to single and simultaneous determination of SMX and TMP in aquaculture waters. The authors acknowledge the financial support from FCT, Fundacão para a Ciência e Tecnologia/FEDER (project PTDC/AGR-AAM/68359/2006). Oneofus (Almeida SAA) is grateful to FCT for the PhD Grant (SFRH/BD/42509/2007). Publicado

Resumen Objetivos Estudiar los efectos del tratamiento de los pacientes con fractura de cadera en una unidad ortogeriatrica conjunta entre los servicios de traumatologia y geriatria comparados con el tratamiento hospitalario habitual y analizar las diferencias de costes entre ambos sistemas de asistencia. Material y metodos Estudio prospectivo cuasi-experimental de intervencion, aleatorizado, en 506 pacientes ingresados en un hospital terciario con el diagnostico de fractura de cadera osteoporotica. El sistema habitual de tratamiento fue el ingreso a cargo de traumatologia con interconsulta a geriatria (tipo IC) y el sistema a estudio consistio en el ingreso en una unidad ortogeriatrica (UOG) para el tratamiento conjunto integrado entre los especialistas en traumatologia y geriatria. Este incluyo la designacion de un interlocutor unico por cada servicio, seguimiento por la enfermera de ortogeriatria, valoracion geriatrica precoz, atencion clinica diaria coordinada, pase de visita conjunto semanal y planificacion coordinada de la programacion quirurgica, del inicio de la deambulacion y del destino y momento del alta. Resultados Se incluyo a 255 pacientes consecutivos ingresados en la UOG y 251 tratados simultaneamente mediante IC. No existieron diferencias, salvo por una edad ligeramente inferior en el grupo de UOG, en las caracteristicas previas ni en la tasa de intervencion quirurgica de ambos grupos. En los pacientes de la UOG fue mas frecuente recibir rehabilitacion en la fase aguda, ser capaz de caminar al alta y ser derivado a unidades de recuperacion funcional (todas con p Conclusiones La UOG es un nivel asistencial que aporta mejoras en la evolucion funcional de los pacientes y una reduccion total de estancias hospitalarias. En base a ello reduce los costes de asistencia. Estos resultados hacen recomendable este sistema de atencion a los pacientes con fractura de cadera en fase aguda.

A general procedure is presented for the fabrication of miniaturized continuous flow analytical microsystems based on photometric detection using the low temperature co-fired ceramics technology. Optical elements such as light emitting diodes and photodiodes (all in the size of a few hundred micrometers) are integrated by means of an off-chip approach. A simple procedure is demonstrated to integrate a glass window after the ceramic sintering in order to minimize the decrease in sensitivity due to the reduction of the optical path length when scaling down. A flow cell with a shape of a bubble has been used to increase the area of the light beam. The device is robust, affordable, and small-sized. It enables absorbance measurements to be performed in-situ or for continuous monitoring of environmental samples. Specifically, a microsystem is introduced for colorimetric determination of chromium (VI) ion in waters based on the diphenylcarbazide reagent as a model. Under the optimized conditions, a linear response is obtained for the concentration range from 0.1 to 20 mg L-1, with a detection limit of 50 μg L-1.

A multicommutation-based flow system with photometric detection was developed, employing an analytical microsystem constructed with low temperature co-fired ceramics (LTCC) technology, a solid-phase reactor containing particles of Canavalia ensiformis DC (urease source) immobilized with glutaraldehyde, and a mini-photometer coupled directly to the microsystem which monolithically integrates a continuous flow cell. The determination of urea in milk was based on the hydrolysis of urea in the solid-phase reactor and the ammonium ions produced were monitored using the Berthelot reaction. The analytical curve was linear in the urea concentration range from 1.0 x 10(-4) to 5.0 x 10(-3) mol L(-1) with a limit of detection of 8.0 x 10(-6) mol L(-1). The relative standard deviation (RSD) for a 2.0 x 10(-3) mol L(-1) urea solution was lower than 0.4% (n = 10) and the sample throughput was 13 h(-1). To check the reproducibility of the flow system, calibration curves were obtained with freshly prepared solutions on different days and the RSD obtained was 4.7% (n = 6). Accuracy was assessed by comparing the results of the proposed method with those from the official procedure and the data are in close agreement, at a 95% confidence level.

The construction and evaluation of a Low Temperature Co-fired Ceramics (LTCC)-based microsystem prototype as a possible on-site microanalyzer to monitor the presence of two ions in water simultaneously is presented. The approach has been assayed to detect nitrate and chloride ions as model analytes by means of integrating in the same single substrate an ion selective polymeric membrane to nitrate and two screen-printed Ag/AgCl electrodes. One supplies the chloride ion concentration and the other is to complete the potentiometric detection system as the reference electrode. The results obtained by the full characterization of the microanalyzer prove the relevance of the proposal and the possibility to be transferred to real-world samples and environmental monitoring.

Low-temperature cofired ceramics (LTCC) technology is a versatile fabrication technique used to construct microflow systems. It permits the integration of several unitary operations (pretreatment, separation, (bio)chemical reaction, and detection stage) of an analytical process in a modular or monolithic way. Moreover, because of its compatibility with biological material, LTCC is adequate for analytical applications based on enzymatic reactions. Here we present the design, construction, and evaluation of a LTCC microfluidic system that integrates a microreactor (internal volume, 24.28 microL) with an immobilized beta-galactosidase from Escherichia coli (0.479 activity units) and an optical flow cell to measure the product of the enzymatic reaction. The enzyme was immobilized on a glyoxal-agarose support, maintaining its activity along the time of the study. As a proof of concept, the LTCC-beta-galactosidase system was tested by measuring the conversion of ortho-nitrophenyl beta-D-galactopyranoside, the substrate usually employed for activity determinations. Once packed in a monolithically integrated microcolumn, the miniaturized flow system was characterized, the operational conditions optimized (flow rate and injection volume), and its performance successfully evaluated by determining the beta-galactosidase substrate concentration at the millimolar level.

A novel fluorescence dip-probe POF (Polymer Optical Fiber) sensor that allows performing in situ chemical determinations has been fabricated. The dip-probe sensor design has been optimized by simulations in order to improve the fluorescence collection. To demonstrate its possibilities, it has been chemically activated with a lead-selective plasticized PVC (polyvinylchloride) membrane containing a new synthesized suitable fluoroionophore and a commercial lead ionophore. The analytical response of the dip-probe sensor has been characterized and it shows a fully reversible response with a sensitivity of −35.10 mV/dec C and a Pb2+ detection limit of 7 × 10−6 M, which can be appropriate for monitoring contamination episodes. No significant interferences with other metal ions have been found. The device has been finally tested to determine the lead content in contaminated natural samples with promising results.

In this work, selective chemical sensors of phosphorus (PO4 3−) installed in PVC probes and their associated instrumentation were evaluated in soil solution phosphorous monitoring. The evaluation was carried out with the addition of a 0.1 mol L−1 P‐PO4 3− solution in the soil, followed by data acquisition supplied by the probes; by collecting soil samples in the region where the probes were installed; and by phosphorus determination through conventional laboratory techniques. The phosphorus amounts were determined by spectrophotometry after the following extraction methodologies: Mehlich 1, Mehlich 3, and ionic exchange resin. The results, compared with the potentials registered by the probes, express the best correlation with the results obtained with the resin method. The results indicate good response of the sensors and the potential applicability of these probes to assist in the monitoring of soil nutrients, helping to establish rational processes in the use of fertilizers in crops.

A miniaturized and robust optical fluorosensor, designed as a portable instrumentation for the in situ analysis of ions in water samples by using optodes has been constructed with low cost discrete optical components. The chemical recognition element of the device consists of a plasticized PVC-based fluorescent optode, which includes a new hexamethine–hemicyanine dye as a fluorophore. The signal can be attributed to a certain analyte depending on the ionophore employed. In this work, a commercial potassium ionophore (valinomycin) has been used to formulate a model membrane selective to potassium. The sensor has been fully characterized using a simple flow injection analysis (FIA) system and analytical parameters such as sensitivity (0.71 mV dec −1 ), limit of detection (2.2 × 10 −5 M K + ), repeatability (R.S.D. = 4.2%), reproducibility, lifetime and ionic interferences have been determined. The developed miniaturized system has been applied to the potassium concentration determination in spiked tap water samples. The obtained results have been compared to those acquired by the ICP-OES reference method and the suitability of the experimental setup for the determination of ions in water samples by the miniaturized fluorescence proposal has been demonstrated.

The integration of optical detection methods in continuous flow microsystems can highly extend their range of application, as long as some negative effects derived from their scaling down can be minimized. Downsizing affects to a greater extent the sensitivity of systems based on absorbance measurements than the sensitivity of those based on emission ones. However, a careful design of the instrumental setup is needed to maintain the analytical features in both cases. In this work, we present the construction and evaluation of a simple miniaturized optical system, which integrates a novel flow cell configuration to carry out chemiluminescence (CL) measurements using a simple photodiode. It consists of a micromixer based on a vortex structure, which has been constructed by means of the low-temperature cofired ceramics (LTCC) technology. This mixer not only efficiently promotes the CL reaction due to the generated high turbulence but also allows the detection to be carried out in the same area, avoiding intensity signal losses. As a demonstration, a flow injection system has been designed and optimized for the detection of cobalt(II) in water samples. It shows a linear response between 2 and 20 muM with a correlation of r > 0.993, a limit of detection of 1.1 muM, a repeatability of RSD = 12.4 %, and an analysis time of 17 s. These results demonstrate the suitability of the proposal to the determination of compounds involved in CL reactions by means of an easily constructed versatile device based on low-cost instrumentation. This work was supported by the Spanish "Comisión Interministerial de Ciencia y Tecnología" through Projects CICYT-TEC2006-13907-C04/MIC and PTR1995-0770-OP and Project MEC (PHB2004-0105-PC)-CAPES. Publicado

Los moluscos acumulan metales pesados y ponen en riesgo la salud del consumidor. Entre estos metales, el mercurio esta considerado como no esencial y muy toxico. Se determino la concentracion de mercurio en mejillones, berberechos y navajas, en conservas comercializadas en Galicia (Espana). Las porciones de musculo, hepatopancreas y liquido de cobertura se sometieron a un proceso de digestion, en medio acido, en microondas. El mercurio se analizo por voltamperometria de redisolucion anodica con electrodo de oro. Los resultados para molusco completo, expresados en ppm y peso fresco, mostraron los mayores niveles para mejillones (0,27), seguidos de berberechos (0,20) y finalmente las navajas (0,08). El contenido de mercurio por porciones fue: hepatopancreas > liquido de cobertura > musculo. Todas las concentraciones de mercurio estuvieron por debajo del limite maximo permitido para consumo humano. Por tanto, su consumo no supone riesgo alguno para la salud del consumidor.

A novel compact dual-wavelength measurement system for absorbance chemical sensing incorporating digital lock-in amplifiers is reported. Its main innovation is the introduction of a reference wavelength to correct the possible non-specific optical changes of the system. The performance of the instrumentation has been tested on a laboratory setup and with integrated optical absorbance sensors.

An agrarian sensorial system based on temperature, moisture, and all solid-state ion-selective potentiometric sensors was developed with the objective of monitoring the behavior of H+ and Ca2+ ions in soil and in real conditions, contributing with a new tool that tries to complement the current precision agriculture technology. The evaluation of the sensorial system to pH monitoring presented a good correlation between the results obtained by the system and the standard methodology, allowing us to notice the soil buffer capacity at different soil depths. With regard to calcium, the sensor system also presented an agreement between its results and those obtained by flame atomic absorption spectrometry, using a calibration model based on multiple linear regressions that allows the correct determination of Ca2+ concentrations in soil depths where the relative moisture is different. In this way, using well-known potentiometric sensors in a complex, discontinued, and heterogeneous matrix, such as soil, the sensorial system proved to be a useful task for agrochemical field applications.

Among the several fabrication techniques used to construct microflow systems, the low-temperature cofired ceramics (LTCC) technology, taking advantage of its multilayer approach, is one of the most versatile ones. It permits the integration of several unitary operations of an analytical process in a modular or monolithic way. Moreover, due to its perfect compatibility with screen-printing techniques, it also permits the integration of electronic components used to control the whole system setup. In this work the design, construction, and evaluation of a miniaturized analyzer for pesticide determination that integrates a pretreatment stage, based on two mixers or reactors, and an amperometric detection system to measure the product of an enzymatic inhibition reaction are presented. The detection system was monolithically integrated in the microfluidic platform, and it consisted of a screen-printed reference electrode and two platinum sheets, acting as auxiliary and working electrodes, which were embedded within the ceramic structure. The miniaturized system was characterized and successfully evaluated by determining carbofuran at the nanomolar level.

New norcyanine dyes were characterised for their use as long wavelength chromoionophores in optodes. Different membrane compositions were formulated for pH determination in water and their response in terms of sensitivity, linear range, response time and reversibility was examined with the aim to apply them in planar optochemical sensors. Their absorbance maxima are located in the NIR region (785–830 nm), which is very appropriate for applications using common low cost telecommunication components. The characterised optodes showed good analytical features. Hence, fully reversible, reproducible, fast, and sensitive bulk optodes were obtained. The photostability of dyes in the plasticised matrices and their tendency to leach from the membrane phase were also evaluated at different conditions.

New far-visible absorbing anilino-cyanine dyes have been synthesised for future application as chromoionophores in integrated waveguide absorbance optodes based on bulk optodes. The effect of the heterocycle, of the substitution of the heterocyclic nitrogen and of the type of heptamethine central ring on the pKa values (4.3–8.2 in ethanol–water solutions and 9.5–11.0 in plasticised PVC membranes), on the spectroscopic characteristics of the dye and on photostability is discussed. pH-selective bulk optodes have been formulated as a first approach to develop ion-selective optodes, and sensitivity, repeatability, lifetime and response time have been determined. The dyes show good analytical behaviour for use as chromoionophores for the development of ion-selective optodes. Reversible (80–87%), fast (tr90% = 0.94–2.28 min) and pH-sensitive membranes (slopes of 0.09–0.23 ΔAbs·pHdec–1, absorbance range 0.19–0.53) have been obtained. Moreover, they exhibit good spectroscopic features for employment with integrated optochemical sensors: absorption maxima of the acidic species in plasticised PVC membranes matched those of 650–670-nm LEDs, high molar absorption coefficients (\( \varepsilon _{{{\text{acidic}}}} = 3.5 \times 10^{4} - 9.3 \times 10^{4} \) L mol–1 cm–1 and \( \varepsilon _{{{\text{basic}}}} = 1.9 \times 10^{4} - 6.7 \times 10^{4} \) L mol−1 cm−1) and fluorescence.