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The FIA-photo-Fenton system is based on the flow oxidation of the organic matter. A small amount of the sample containing H2O2 is injected into the acidic flow solution of Fe2+, which passes through a tubular PTFE reactor irradiated with UV light. The generated CO2 is quantified by a conductometric detector and is directly proportional to the dissolved organic carbon concentration in the sample. The optimization studies were performed using EDTA solutions. The average recovery of organic carbon was 83% with a relative standard deviation of 3.7% using a 1:5 molar ratio of Fe2+:H2O2, pH 2.0, 100 muL of sample injection and a liquid flow of 1 mL min-1. After optimization, the DOC concentration was quantified using 13 different organic compounds, where the average recovery was 90%. The rate of the analysis was in average 50 samples hour-1.O sistema FIA-foto-Fenton é baseado na oxidação em fluxo da matéria orgânica. Uma pequena quantidade de amostra contendo H2O2 é introduzida no fluxo de uma solução ácida de Fe2+, que passa por um reator tubular de PTFE irradiado com luz UV. O CO2 gerado é quantificado condutometricamente e é diretamente proporcional à concentração de carbono orgânico dissolvido na amostra. Os estudos de otimização foram realizados empregando soluções de EDTA. A recuperação média de carbono orgânico foi de 83% com desvio padrão relativo de 3,7% empregando 100 miL de amostra, pH 2,0, razão molar entre Fe2+ e H2O2 de 1:5 e uma vazão de 1 mL.min-1. Após otimização as concentrações de DOC foram quantificadas em 13 diferentes compostos orgânicos, com uma recuperação média de 90%. A velocidade de análise foi em média 50 amostras/h.

A PLS-2 multivariate calibration method has been developed for the simultaneous determination of iron, nickel and zinc in ternary mixtures by solid phase spectrophotometry associated with flow injection analysis. Fe(II), Ni(II) and Zn(II) form color complexes with 1-(2-thiazolylazo)-2-naphthol (TAN), immobilized on a C18 bonded silica support, at pH 6.4. The proposed procedure is based on the different reaction/retention ratios of the studied ions on the solid support. Bilinear spectrophotometric data of the analytes, fixed in the solid support, were recorded in the 400-800 nm wavelength range as a function of time and a partial least squares (PLS-2) algorithm was used to predict results of synthetic samples. The calibration set employed was integrated by 8 ternary mixture standards and a blank solution. Mixtures containing 0.040 to 0.20 mg L-1, of each species, were successfully resolved, using 3 factors for each analyte and a restricted number of absorbance data obtained in the wavelength range from 560 to 650 nm.

• Productivity is positively impacted by tree species richness and stand density. • Southeastern U.S. forests have a diverse representation of tree functional traits. • Structural equation modeling allows for complex analyses of ecological processes. • Long-term, large-scale analysis of diversity and productivity for 122 tree species. Numerous studies have evaluated the relationship between tree species diversity and productivity, with general trends suggesting a positive relationship. While most studies only use species richness, this study also analyzed how productivity changes with functional diversity and Shannon-Wiener's diversity index, to compare the impact of these different indicators of tree species diversity. This study used data from the USDA Forest Service Forest Inventory and Analysis (FIA) database collected in Alabama, Louisiana, and Mississippi to estimate plot-level productivity and diversity. Structural equation modeling was used to determine the strength of the relationship between different measures of tree species diversity and forest productivity directly and indirectly. This study found that species richness had the greatest influence on forest productivity, but it was largely an indirect effect mediated by stand density. Functional diversity did not have a substantial relationship with productivity while Shannon- Wiener's diversity index was negatively related to productivity when modeled with the other diversity indicators and mediated through stand density. The methodology of this research provides a framework for a similar analysis expanded spatially to other regions of the US to include more forest types for comparison of trends with the use of FIA data. [ABSTRACT FROM AUTHOR]

A flow injection system using a tubular electrode based on the redox properties of copper (II) ions occluded in EVA membrane was developed for L-ascorbic acid determination. The poly-ethylene-co-vinyl acetate (EVA 40% m/m) matrix was doped with copper (II) ions and dispersed on the surface of a graphite/epoxy tubular electrode. The electrode showed a super-Nernstian response for L-ascorbic acid concentration between 10-3 and 10-1 mol L-1 with a detection limit of 8.5×10-4 mol L-1, when 0.1 mol L-1 KH2PO4 buffer mixed with 0.1 mol L-1 hydrogen peroxide at pH 5.0 was employed as carrier. The Potentiometric-FIA system allows an analytical frequency of 120 samples per hour with a precision of 3.6%. The results obtained for ascorbic acid determination in pharmaceutical samples, without any previous treatment, were similar to those obtained by the British Pharmacopoeia method.

Anodic electrodissolution procedure in a flow injection system for determination of constituents in alloys is discussed. This approach implement sample preparation procedure by using a chamber and a DC power supply with constant direct current. Solid sample was attached to chamber as anode. In this review a general overview of these procedure is presented. The procedure presented a good performance characterized by a high sample throughput determinations, good accuracy and relative standard deviation.

An analytical procedure was developed for the simultaneous determination of acetaminophen (ACP) and tramadol (TRA) by flow injection analysis with multiple pulse amperometric detection (FIA–MPA) using a cathodically pretreated boron-doped diamond electrode (BDDE). The proposed method was applied to the simultaneous determination of ACP and TRA in pharmaceutical samples and synthetic biological fluids. The obtained results are in acceptable levels, the proposed method presents low RSD values (< 2.70 and 4.70% for intra- and inter-day, respectively), linear ranges from 1.0 to 100 μmol L − 1 for ACP and from 0.08 to 10 μmol L − 1 for TRA, limits of detection of 0.03 and 0.04 μmol L − 1 for ACP and TRA, respectively, elevated analytical frequency (approximately 85 injections h − 1 ) and adequate accuracy (confirmed by comparison with HPLC results). [ABSTRACT FROM AUTHOR]

Control of chemotherapies preparations are now an obligation in France, though analytical control is compulsory. Several methods are available and none of them is presumed as ideal. We wanted to compare them so as to determine which one could be the best choice. We compared non analytical (visual and video-assisted, gravimetric) and analytical (HPLC/FIA, UV/FT-IR, UV/Raman, Raman) methods thanks to our experience and a SWOT analysis. The results of the analysis show great differences between the techniques, but as expected none us them is without defects. However they can probably be used in synergy. Overall for the pharmacist willing to get involved, the implementation of the control for chemotherapies preparations must be widely anticipated, with the listing of every parameter, and remains according to us an analyst’s job. [ABSTRACT FROM AUTHOR]

Wall-to-wall remotely sensed data are increasingly available to monitor landscape dynamics over large geographic areas. However, statistical monitoring programs that use post-stratification cannot fully utilize those sensor data. The Kalman filter (KF) is an alternative statistical estimator. I develop a new KF algorithm that is numerically robust with large numbers of study variables and auxiliary sensor variables. A National Forest Inventory (NFI) illustrates application within an official statistics program. Practical recommendations regarding remote sensing and statistical issues are offered. This algorithm has the potential to increase the value of synoptic sensor data for statistical monitoring of large geographic areas. [ABSTRACT FROM AUTHOR]

Generating accurate and unbiased wall-to-wall canopy height maps from airborne lidar data for large regions is useful to forest scientists and natural resource managers. However, mapping large areas often involves using lidar data from different projects, with varying acquisition parameters. In this work, we address the important question of whether one can accurately model canopy heights over large areas of the Southeastern US using a very heterogeneous dataset of small-footprint, discrete-return airborne lidar data (with 76 separate lidar projects). A unique aspect of this effort is the use of nationally uniform and extensive field data (∼1800 forested plots) from the Forest Inventory and Analysis (FIA) program of the US Forest Service. Preliminary results are quite promising: Over all lidar projects, we observe a good correlation between the 85th percentile of lidar heights and field-measured height (r = 0.85). We construct a linear regression model to predict subplot-level dominant tree heights from distributional lidar metrics (R2 = 0.74, RMSE = 3.0 m, n = 1755). We also identify and quantify the importance of several factors (like heterogeneity of vegetation, point density, the predominance of hardwoods or softwoods, the average height of the forest stand, slope of the plot, and average scan angle of lidar acquisition) that influence the efficacy of predicting canopy heights from lidar data. For example, a subset of plots (coefficient of variation of vegetation heights <0.2) significantly reduces the RMSE of our model from 3.0-2.4 m (∼20% reduction). We conclude that when all these elements are factored into consideration, combining data from disparate lidar projects does not preclude robust estimation of canopy heights. [ABSTRACT FROM AUTHOR]

Phthalocyanines and metallophthalocyanines play a very important role in the metabolism of living organisms through biological pigments or biochromes and are therefore also employed in numerous applications in analytical chemistry. In flow-, and sequential-injection analysis and microfluidic systems the role of phthalocyanines and metallophthalocyanines is centered as either that of analyte or that of a reagent or modifier in the determination of other species. This paper covers the attributes of phthalocyanines and metallophthalocyanines complexes as enhancements in chemical analysis in flow- and sequential injection analysis and microfluidic systems and points out the advantages and disadvantages in the implementation thereof. [ABSTRACT FROM AUTHOR]

25-Hydroxyvitamin D [25(OH)D], the predominant circulating form of vitamin D, is an accurate indicator of the general vitamin D status of an individual. Because vitamin D deficiencies have been linked to several pathologies (including osteoporosis and rickets), accurate monitoring of 25(OH)D levels is becoming increasingly important in clinical settings. Current 25(OH)D assays are either chromatographic or immunoassay-based assays. These assays include HPLC, liquid chromatography-tandem mass spectrometry (LC-MS/MS), enzyme-immunosorbent, immunochemiluminescence, immunofluorescence and radioimmunoassay. All these assays use heterogeneous formats that require phase separation and special instrumentations. In this article, we present an overview of these assays and introduce the first homogeneous assay of 25(OH)D for use on general chemistry analyzers. A special emphasis is put on the unique challenges posed by the 25(OH)D analyte. These challenges include a low detection limit, the dissociation of the analyte from its serum transporter and the inactivation of various binding proteins without phase separation steps. [ABSTRACT FROM PUBLISHER]

A commercially available thin-layer flow-through amperometric detector, with the sensing block customized in an original design, was applied to the screening of drug compounds known as acetylcholinesterase (AChE) inhibitors. AChE from electric eel was covalently immobilized onto a cysteamine modified gold disk adjacent to a silver disk working electrode. On-line studies were performed by flow injection analysis (FIA) in PBS buffer pH 7.4. Seven commercially available AChE inhibitors used in the medical field, namely neostigmine, eserine, tacrine, donepezil, rivastigmine, pyridostigmine and galantamine as well as two natural compounds, quercetin and berberine, were investigated. The same trend of inhibitory potency as described in the literature was observed. Of particular interest and in addition to the determination of the IC 50 values, this flow-through system allowed the study of both, the stability of the enzyme-inhibitor complex and the kinetic of the enzyme activity recovery. [ABSTRACT FROM AUTHOR]

Forest disturbances can have broad impact on the climate, local environment, and the regeneration of the forest ecosystem. The nature and magnitude of such impact is largely driven by disturbance intensity. In this study, by integrating field plot measurements collected by the Forest Inventory and Analysis program with time series Landsat observations, we produced the first set of annual forest disturbance intensity map products quantifying the percentage of basal area removal (PBAR) at the 30-m resolution for the conterminous United States (CONUS) from 1986 to 2015. The derived map products revealed that during the 30-year study period, the annual average PBAR values of all disturbed pixels across CONUS ranged from 66% to 70%, and the proportion of those pixels having stand-clearing disturbances ranged from 40% to 58%. High disturbance intensities were concentrated in the Southeastern states from Texas to Virginia and along the Pacific coast and the Cascades in the West. At the national scale, the annual mean PBAR and proportion of stand clearing area (PSCA) values both appeared to follow second order trajectories, with increasing trends at the beginning, decreasing trends towards the end, and turning points around 2003. Overall, there is a net increase of 2% in PBAR and 3% in PSCA from 1986 to 2015. The temporal trends of PBAR and PSCA were also investigated at state and ecoregion levels, with substantial differences found among many states and ecoregions. While states and ecoregions generally follow second order trajectories, the majority had increasing trends throughout much of the study period, reflecting higher disturbance intensities during the later years compared to earlier years. Large increase (>10%) in PBAR was seen in several states (e.g., Virginia, Arkansas, and Minnesota) and ecoregions (e.g., Northern Minnesota Wetlands); however, large decreases (>10%) in PBAR were not observed in any states, and were seen in only one ecoregion, the Blue Mountains in the southeast. The disturbance intensity maps are available from a web portal of the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL-DAAC) at https://doi.org/10.3334/ORNLDAAC/2059. • We produced the first annual forest disturbance intensity map series for CONUS. • The percentage of basal area removal (PBAR) from disturbance ranged from 66% to 70%. • Stand-clearing events (PBAR ≥ 80%) accounted for 40%–58% of all disturbances. • CONUS-wide average PBAR increased by 2% in absolute value from 1986 to 2015. • The temporal trends of PBAR differed substantially among many states and ecoregions. [ABSTRACT FROM AUTHOR]

This paper describes the development of an electrochemical sensor coupled to flow injection analysis system for the detection of pesticides. The proposed sensor was prepared using a carbon paste electrode modified with hemin and nickel (II) 1,48,11,15,18,22,25-octabutoxy-29H, 31H-phthalocyanine complex as possible catalysts P450 enzyme and graphene oxide in order to improve the sensitivity of the sensor. In the first place, we used the cyclic voltammetry in a response range of −0.2 to 1 V to monitor the electrochemical response of each pesticide. In optimized conditions, an amperometric study of the proposed sensor was conducted applying the potential of 0.45 and 0.8 V for the redox reaction of carbofuran-phenol and diuron. The system showed a linear response in a concentration range between 5.0 × 10 −6 and 1.4 × 10 −4 and 5.0 × 10 −5 and 1.0 × 10 −3 mol L −1 and detection limit of 1.7 × 10 −6 and 2.0 × 10 −5 mol L −1 for carbofuran and diuron, respectively. The proposed sensor was applied in soil and carrot samples and the results obtained in the recovery study were close to 100%. The reliability of the proposed sensor was confirmed after comparing the results with those obtained in the comparative method (HPLC). [ABSTRACT FROM AUTHOR]

Mobile devices are expected to become the Internet's predominant technology. Current protocols such as TCP/IP were not originally designed with mobility as a key consideration, and therefore underperform under challenging mobile and wireless conditions. MobilityFirst, a clean slate architecture proposal, embraces several key concepts centered around secure identifiers that inherently support mobility and trustworthiness as key requirements of the network architecture. This includes a hop-by-hop segmented data transport based on a globally unique identifier. This allows late and dynamic rebinding of end-point addresses to support mobility. While this provides critical gains in wireless segments, some overheads are incurred even in stable segments such as in the core. Bypassing routing-layer decisions in these cases, with lower layer cut-through forwarding, can improve said gains. In this work, we introduce a general bypass capability within the MobilityFirst architecture that provides better performance and enables both individual and aggregate flow-level traffic control. Furthermore, we present an OpenFlow-based proof-of-concept implementation of the bypass function using layer 2 VLAN tagging. We run experiments on the ORBIT and Global Environment for Network Innovations (GENI) testbeds to evaluate the performance and scalability of the solution. By implementing the bypass functionality, we are able to significantly reduce the number of messages processed by the controller as well as the number of flow rules that need to be pushed into the switches. [ABSTRACT FROM AUTHOR]

Abstract: A new, highly sensitive fluorescence immunoassay for a TIRF (total internal reflection)-based point-of-care testing (POCT) device was developed for the detection of procalcitonin (PCT), a specific and early marker for sepsis and microbial infections. The immunoassay was performed on a bench-top system that fulfilled all the necessary characteristics of a POCT application, including a short measurement time (<9min), no sample pre-treatment requirements and application directly near patients. New rat monoclonal antibodies targeting PCT were screened and characterized. The best combinations of antibodies were then integrated into single-use cartridges, and the reduction of nonspecific binding was achieved by supplying suitable additives. Moreover, human recombinant PCT (hrPCT) for use as a standard was developed in the native form of hPCT in plasma (PCT1-116, PCT3-116). The assay achieves the required sensitivity range in human plasma to allow reliable differentiation between healthy persons and varying stages of infection severity (LOD=0.04ng/mL; LOQ=0.12ng/mL). Furthermore, the developed PCT assay can be applied in whole human blood with an adequate sensitivity (LOD=0.02ng/mL; LOQ=0.09ng/mL). To the best of our knowledge, this is the first diagnostic test for sepsis to use whole blood, which is a crucial requirement for POCT. We were able to detect native PCT in patient samples and showed a good correlation (R 2=0.988) with the results of the Kryptor® device from BRAHMS, a state of the art device for the detection of PCT. [Copyright &y& Elsevier]

A flow procedure based on a multicommuted flow analysis process for the determination of polyphenolic compounds in wine employing chemiluminescence as detection technique is described. The method was based on the reaction of hypochlorite with gallic acid, the remaining hypochlorite reacted with luminol in an alkaline medium generating electromagnetic radiation with maximum emission at 425 nm. The luminescence intensity presented an inverse relationship to the concentration of polyphenol compounds, which was monitored employing a homemade luminometer. The flow system manifold was designed to use solenoid mini-pumps for propelling fluids in order to obtain a setup of downsized dimension. After setting the variables control of the flow system and the concentrations of the reagent, the following features were achieved: a linear response ranging from 10 to 100 mg L gallic acid ( R = 0.997), a relative standard deviation of 3.4 ( n = 11) for a 50 mg L gallic acid solution, a detection limit of 6.6 mg L, a sampling throughput of 180 determination h, and a waste generation of 1.1 mL per determination. [ABSTRACT FROM AUTHOR]

In a shipyard production system, launching operation is vital process since launching stage is time consuming process as well as being high cost. Therefore, this is a significant issue for shipyards. Choosing the most appropriate one among launching methods gives an advantage to shipyards to obtain competitive power against their competitors. If this is done, shipyards can commit to delivery of more ships and make more profit. In this study, launching methods are evaluated in terms of various performance criteria by means of an integrated method including Analytic Hierarchy Process (AHP), Fuzzy Information Axiom (FIA), Technique for Order Performance by Similarity to Ideal Solution (TOPSIS), and Strengths, Weaknesses, Opportunities, and Threats (SWOT) analyses. Then, the dry docking technique was determined as the most convenient launching method with respect to the conflicting criteria. [ABSTRACT FROM AUTHOR]

The critical role of forests in the global carbon cycle is well known, but significant uncertainties remain about the specific role of disturbance, in part because of the challenge of incorporating spatial and temporal detail in the characterization of disturbance processes. In this study, we link forest inventory data to remote sensing data to derive estimates of pre- and post-disturbance biomass, and then use near-annual remote sensing observations of forest disturbance to characterize biomass loss associated with disturbance across the conterminous U.S. between 1986 and 2004. Nationally, year-to-year variability in the amount of live aboveground carbon lost as a result of disturbance ranged from a low of 61 T C (±16) in 1991 to a high of 84 T C (±33) in 2003. Eastern and western forest strata were relatively balanced in terms of their proportional contribution to national-level trends, despite eastern forests having more than twice the area of western forests. In the eastern forest stratum, annual biomass loss tracked closely with the area of disturbance, whereas in the western forest stratum, annual biomass loss showed more year-to-year variability that did not directly correspond to the area of disturbance, suggesting that the biomass density of forests affected by disturbance in the west was more spatially and temporally variable. Eastern and western forest strata exhibited somewhat opposing trends in biomass loss, potentially corresponding to the implementation of the Northwest Forest Plan in the mid 1990s that resulted in a shift of timber harvesting from public lands in the northwest to private lands in the south. Overall, these observations document modest increases in disturbance rates and associated carbon consequences over the 18-year period. These changes are likely not significant enough to weaken a growing forest carbon sink in the conterminous U.S. based largely on increased forest growth rates and biomass densities. [ABSTRACT FROM AUTHOR]

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Restoration of foundation species, such as the American chestnut (Castanea dentata) that was devastated by an introduced fungus, can restore ecosystem function. Understanding both the current distribution as well as biogeographic patterns is important for restoration planning. We used United States Department of Agriculture Forest Service Forest Inventory and Analysis data to quantify the current density and distribution of C. dentata. We then review the literature concerning biogeographic patterns in C. dentata. Currently, 431 ± 30.2 million stems remain. The vast majority (360 ± 22 million) are sprouts

We have prepared a surface imprinted polymer (SIP) film for label-free recognition of immunoglobulin G (IgG). The IgG-SIPs were obtained by covalent immobilization of IgG via a cleavable covalent bond and a suitable spacer unit to a gold electrode, followed by electrodepostion of a nm-thin film of polydopamine (PDA). The IgG was then removed by destruction of the cleavable bond so that complementary binding sites were created on the surface of the film. IgG-SIPs with various thicknesses of the PDA films were compared with respect to their affinity to IgG using a quartz crystal microbalance combined with flow injection analysis. The films were also characterized by cyclic voltammetry and scanning electron microscopy. The IgG-SIPs with a film thickness of around 17 nm showed the most pronounced imprinting effect (IF 1.66) and a binding constant of 296 nM. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The objective of the present work was to adapt the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to a system of flow injection analysis (FIA) of merging zones to determine the antioxidant capacity of wine samples. The conditions of the FIA system proposed here were optimized with the response surface methodology using central composite rotatable design. The optimization parameters studied here were the carrier flow rate, the length of the sampling and reagent loops, and the length of the reaction coil. The experimental data were fitted to a polynomial model, and the optimal conditions were: flow rate of 1.12 mL min, loop length of 18.5 cm, and reaction coil length of 234.60 cm. The limits of detection and quantification were 2.65 and 8.82 μM of Trolox, respectively. The method proposed had an analytical frequency of 41 analyses per hour and a reagent consumption economy of 57.3 % for DPPH in relation to the conventional method. The results of the antioxidant activities of the wine samples obtained with the proposed method were correlated and compared to those of the conventional method. [ABSTRACT FROM AUTHOR]

Large-scale and long-term habitat management plans are needed to maintain the diversity of habitat classes required by wildlife species. Planning efforts would benefit from assessments of potential climate and land-use change effects on habitats. We assessed climate and land-use driven changes in areas of closed- and open-canopy forest across the Northeast and Midwest by 2060. Our assessments were made using projections based on A1B and A2 future scenarios developed by the Intergovernmental Panel on Climate Change. Presently, forest land covers 70.2 million ha and is evenly divided between closed- and open-canopy habitats. Projections indicated that total forest land would decrease by 3.8 or 4.5 million ha for A2 and A1B, respectively. Within persisting forest land, the balance between closed and open-canopy habitats depended on assumed harvest rates of woody biomass. Standard harvest rates led to closed-canopy habitat attaining a slight majority of total forest land area. Intensive harvest rates resulted in the majority of forest land being in open-canopy habitat for A1B or maintained the even split between closed- and open-canopy habitats for A2. Ultimately, managers need to identify benchmark habitat conditions informed by historical conditions and wildlife population dynamics and plan to meet these benchmarks in dynamic forest landscapes. [ABSTRACT FROM AUTHOR]

Robust monitoring of carbon sequestration by forests requires the use of multiple data sources analyzed at a common scale. To that end, model-based Moderate Resolution Imaging Spectroradiometer (MODIS) and field-based Forest Inventory and Analysis (FIA) data of net primary productivity (NPP) were compared at increasing levels of spatial aggregation across the eastern USA. A total of 52,167 FIA plots and colocated MODIS forest cover NPP pixels were analyzed using a hexagonal tiling system. A protocol was developed to assess the optimal scale as an optimal size of landscape patches at which to map spatially explicit estimates of MODIS and FIA NPP. The optimal mapping resolution (hereafter referred to as optimal scale) is determined using spatially scaled z-statistics as the tradeoff between increased spatial agreement as measured by Pearson's correlation coefficient and decreased details of coverage as measured by the number of hexagons. Spatial sensitivity was also assessed using land cover assessment and forest homogeneity using spatially scaled z-statistics. Pearson correlations indicate that MODIS and FIA NPP are most highly correlated when using large hexagons, while z-statistics indicate an optimal scale at an intermediate hexagon size of 390 km. This optimal scale had more spatial detail than was obtained for larger hexagons and greater spatial agreement than was obtained for smaller hexagons. The z-statistics for land cover assessment and forest homogeneity also indicated an optimal scale of 390 km. [ABSTRACT FROM AUTHOR]

We herein report on the electrocatalytic activity towards the oxidation of NADH of a PVC/TTF-TCNQ composite electrode modified with gold nanoparticles. This electrocatalytic property allows proposing this system as a new alternative for amperometric determination of NADH, without need to add another mediator. The sensor shows a linear response to NADH over a concentration range from 5.0×10−6 M up to 5.0×10−4 M, with a sensitivity of 11.22±0.5 mA M−1 and a detection limit ( S/N=3) of 4.0×10−6 M for measurements in batch and similar data in FIA. [ABSTRACT FROM AUTHOR]

Highlights: [•] Part 91 air tour flights were significantly more likely to crash than their Part 135 counterparts. [•] Fatal air tour crashes were more likely than non-fatal crashes to involve fire, occur during instrument meteorological conditions, and take place away from the airport. [•] The four-point FIA Score appears to be a valid tool for measuring fatality risk in air tour crashes. [ABSTRACT FROM AUTHOR]

This paper examines the maple syrup production potential of American forests by analyzing Forest Inventory & Analysis (FIA) data provided by the US Forest Service on the resource of sugar maple ( Acer saccharum Marsh.) and red maple ( Acer rubrum L.) trees in twenty states. The analysis is based on tree species and size (diameter at breast height, or dbh), ownership category, jurisdiction, the density of maple trees in a stand, and the distance of the stand to an access road. Although there are over 2 billion sugar and red maple trees of tappable size growing in US forests, when narrowed down according to the attributes of an optimal 'sugarbush', there are 100 million potential taps from sugar maples alone and 286 million potential taps with sugar and red maples combined. Overall, 45 % of the tappable-size maple trees are found in stands whose density is not high enough to support commercial sap extraction whereas only 6 % are found in stands that are at least 1.6 km from an access road. The ten states with commercial maple syrup industries have a much higher percentage of their maple trees occurring in stands of optimal density and also contain a higher percentage of sugar maple than red maple trees. States that are utilizing the highest percentage of their potential sugarbushes include Vermont and Maine, whereas states that have significant room for expansion include Michigan, New York, and Pennsylvania. [ABSTRACT FROM AUTHOR]

Highlights: [•] The first use of a potentiometric detector in UPLC is described. [•] The potentiometric detector is also used in HPLC. [•] Alkaloids were sensitively determined. [•] A model is given that describes how adsorption/desorption kinetics determines the detector characteristics. [•] Binding kinetics can be performed with the detector, in Flow injection analysis. [Copyright &y& Elsevier]

Abstract: Dopamine (DA) is one of the most important catecholamine neurotransmitters in the human central nervous system in the brain and plays a key role in the functioning of the renal, hormonal, and cardiovascular systems. Abnormal levels of dopamine are related to neurological disorders, such as schizophrenia and Parkinson''s disease and the control and fluctuations of the amount of dopamine are extremely important in monitoring with analytical systems in the human brain. This review covers the attributes of flow-injection analysis systems with different detection devices and other related techniques for the in vitro and in vivo determination of dopamine as neurotransmitter and points out the advantages and disadvantages in the implementation thereof. [Copyright &y& Elsevier]

Abstract: Chitosan–ferrocene (CHIT–Fc) hybrid was synthesized through covalent modification and its electrochemical properties in immobilized form were studied by using cyclic voltammetry. The hybrid film exhibited reversible electrochemistry with a formal potential of +0.35V (vs. Ag/AgCl) at pH 5.5. The Fc in CHIT matrix retained its electrocatalytic activity and did not diffuse from the matrix. This redox-active hybrid was further employed as a support for immobilization of glucose oxidase (GOx) and whole cells of Gluconobacter oxydans using glutaraldehyde on a glassy carbon electrode (GCE). The experimental conditions were optimized and the analytical characteristics of enzyme and microbial biosensors were evaluated for glucose in flow injection analysis (FIA) system. Under optimized conditions, both enzyme and microbial biosensors exhibited wide linear ranges for glucose from 2.0 to 16.0mM and from 1.5 to 25.0mM, respectively. Moreover, the biosensors have the advantages of relatively fast response times, good reproducibility and stability in FI mode. It was demonstrated that CHIT–Fc provides a biocompatible microenvironment for both bioctalysts and an electron transfer pathway. Additionally, integration of the enzyme and microbial biosensors into the FIA system has several advantages including capability of automation and high throughput at low cost. This promising redox hybrid can be utilized as an immobilization matrix for biomolecules in biosensor systems. [Copyright &y& Elsevier]

Abstract: Two new ion-selective electrodes of the plastic membrane type for the determination of Tolterodine (Tol) were prepared. These electrodes depend on the incorporation of the ion-exchangers of the above mentioned drug with phosphotungestic acid (PTA) or Silicotungestic acid (STA) in a PVC matrix. A comparative study is made between the performance characteristics of electrodes containing ion-exchanger in batch and FIA conditions. The usable concentration range of the electrodes was found to be (1.0×10−5–1.0×10−2 and 5.0×10−5–1.0×10−2 M) in batch and FIA conditions, respectively. The electrodes have nearly the same usable concentration, pH range and exhibited high selectivity toward Tol in the presence of many inorganic cations and can be used in biological fluids such as urine and plasma. The dissolution profile of the investigated drug as well as its assay in pure and pharmaceutical preparations was performed, and the results were relatively accurate and precise as indicated by the recovery values and coefficients of variation. [Copyright &y& Elsevier]

The paper describes a rapid and simple method for the evaluation of the antioxidant capacity in oil in water nanoemulsion. This procedure does not require extensive sample treatment and, most important, does not use any organic solvent for dissolution of the fatty matrix. The nanoemulsions were directly injected in a flow injection (FI) system with an electrochemical detector equipped with a glassy carbon working electrode operating amperometrically at a potential of +0.8 V (vs. Ag/AgCl). Results obtained were compared with those obtained by the Oxygen Radical Absorbance Capacity (ORAC) assay. [ABSTRACT FROM AUTHOR]