Monitoring thrombin generation by electrochemistry: development of an amperometric biosensor screening test for plasma and whole blood

BACKGROUND: Complete investigation of thrombophilic or hemorrhagic clinical presentations is a time-, apparatus-, and cost-intensive process. Sensitive screening tests for characterizing the overall function of the hemostatic system, or defined parts of it, would be very useful. For this purpose, we are developing an electrochemical biosensor system that allows measurement of thrombin generation in whole blood as well as in plasma. METHODS: The measuring system consists of a single-use electrochemical sensor in the shape of a strip and a measuring unit connected to a personal computer, recording the electrical signal. Blood is added to a specific reagent mixture immobilized in dry form on the strip, including a coagulation activator (e.g., tissue factor or silica) and an electrogenic substrate specific to thrombin. RESULTS: Increasing thrombin concentrations gave standard curves with progressively increasing maximal current and decreasing time to reach the peak. Because the measurement was unaffected by color or turbidity, any type of blood sample could be analyzed: platelet-poor plasma, platelet-rich plasma, and whole blood. The test strips with the predried reagents were stable when stored for several months before testing. Analysis of the combined results obtained with different activators allowed discrimination between defects of the extrinsic, intrinsic, and common coagulation pathways. Activated protein C (APC) predried on the strips allowed identification of APC-resistance in plasma and whole blood samples. CONCLUSIONS: The biosensor system provides a new method for assessing thrombin generation in plasma or whole blood samples as small as 10 microL. The assay is easy to use, thus allowing it to be performed in a point-of-care setting.

Three-year efficacy and safety of new- versus early-generation drug-eluting stents for unprotected left main coronary artery disease insights from the ISAR-LEFT MAIN and ISAR-LEFT MAIN 2 trials.

BACKGROUND In percutaneous coronary intervention (PCI) patients new-generation drug-eluting stent (DES) has reduced adverse events in comparison to early-generation DES. The aim of the current study was to investigate the long-term clinical efficacy and safety of new-generation DES versus early-generation DES for PCI of unprotected left main coronary artery (uLMCA) disease. METHODS The patient-level data from the ISAR-LEFT MAIN and ISAR-LEFT MAIN 2 randomized trials were pooled. The clinical outcomes of PCI patients assigned to new-generation DES (everolimus- or zotarolimus-eluting stent) versus early-generation DES (paclitaxel- or sirolimus-eluting stent) were studied. The primary endpoint was the composite of death, myocardial infarction (MI), target lesion revascularization and stroke (MACCE, major adverse cardiac and cerebrovascular event). RESULTS In total, 1257 patients were available. At 3 years, the risk of MACCE was comparable between patients assigned to new-generation DES or early-generation DES (28.2 versus 27.5 %, hazard ratio-HR 1.03, 95 % confidence intervals-CI 0.83-1.26; P = 0.86). Definite/probable stent thrombosis was low and comparable between new-generation DES and early-generation DES (0.8 versus 1.6 %, HR 0.52, 95 % CI 0.18-1.57; P = 0.25); in patients treated with new-generation DES no cases occurred beyond 30 days. Diabetes increased the risk of MACCE in patients treated with new-generation DES but not with early-generation DES (P interaction = 0.004). CONCLUSIONS At 3-year follow-up, a PCI with new-generation DES for uLMCA disease shows comparable efficacy to early-generation DES. Rates of stent thrombosis were low in both groups. Diabetes significantly impacts the risk of MACCE at 3 years in patients treated with new-generation DES for uLMCA disease. ClinicalTrials.gov Identifiers: NCT00133237; NCT00598637.

Generation of an hTERT-restricted, CMV-augmented oncolytic adenovirus capable of tumor-specific transgene expression: Development, characterization, and optimization

Current shortcomings in cancer therapy require the generation of new, broadly applicable, potent, targeted treatments. Here, an adenovirus is engineered to replicate specifically in cells with active human telomerase promotion using a modified hTERT promoter, fused to a CMV promoter element. The virus was also modified to contain a visible reporter transgene, GFP. The virus, Ad/hTC-GFP-E1 was characterized in vitro and demonstrated tumor specific activity both by dose and over time course experiments in a variety of cell lines. In vivo, Ad/hTC-GFP-E1 was affected at suppressing tumor growth and providing a survival benefit without causing any measurable toxicity. To increase the host range of the vector, the fiber region was modified to contain an RGD-motif. The vector, AdRGD/hTC-GFP-E1, was recharacterized in vitro, revealing heightened levels of infectivity and toxicity however maintaining a therapeutic window between cancer and normal cell toxicity. AdRGD/hTC-GFP-E1 was administered in vivo by limb perfusion and was observed to be tumor specific both in expression and replication. To further enhance the efficacy of viral vectors in lung delivery, asthma medications were investigated for their abilities to enhance transgene delivery and expression. A combination of bronchodilators, mast cell inhibitors, and mucolytic agents was devised which demonstrated fold increases in expression in immunocompetent mouse lungs as single agents and more homogenous, intense levels of expression when done in combination of all agents. To characterize the methods in which some cancers are resistant or may become resistant to oncolytic treatments, several small molecule inhibitors of metabolic pathways were applied in combination with oncolytic infection in vitro. SP600125 and PD 98059, respective JNK and ERK inhibitors, successfully suppressed oncolytic toxicity, however did not affect infectivity or transgene expression of Ad/hTC-GFP-E1. JNK and ERK inhibition did significantly suppress viral replication, however, as analyzed by lysate transfer and titration assays. In contrast, SB 203580, an inhibitor for p38, did not demonstrate any protective effects with infected cells. Flow cytometric analysis indicated a possible correlation with G1 arrest and suppressed viral production, however more compounds must be investigated to clarify this observation. ^

Seroprevalence of toxoplasmosis and current thinking regarding screening in pregnancy: A review of the literature and case study discussion

The approach to the diagnosis and treatment of congenital toxoplasmosis has been one of flux and debate, fueled by lack of knowledge, lack of consensus, different methods of screening and different national policies for screening in different parts of the world. Countries with higher prevalence of disease such as in Europe and South America have a heightened awareness of the need to screen and treat for this parasitic infection during pregnancy. In contrast, in the United States, it is a condition scarcely discussed and has been largely ignored except in some large centers and by a few researchers. Policies and research strategies for any condition should start with obtaining good data. The aims of this thesis included a review of prevalence studies conducted in the United States, focused on the past 20 years, combined with a description of original research conducted by the author several years ago. The latter was a cross-sectional study performed in Houston, one of the largest American cities with a great ethnic mix. The study analyzed prevalence rates of Toxoplasma gondii IgG antibody in sera of women of reproductive age. Overall seroprevalence was 12.3%. In keeping with other studies, higher prevalence correlated with lower socioeconomic status, Black and Hispanic and Asian ethnicities, and increasing age. A literature search revealed only three prevalence studies performed in the United States over the past 20 years, with another four studies only referred to as personal communications or within a textbook, without further study detail available. The literature review also revealed a lack of consensus on whether or not to screen for toxoplasmosis in pregnancy, and even whether or not treatment in utero is worthwhile.^ Proponents of screening and treatment in pregnancy site studies both in the United States and France, emphasize that treatment reduces disease manifestations in infants. Opponents cite other studies that show only marginal benefits, together with potential side effects of medication regimens and generation of anxiety in parents. What is agreed on so far is the value of educating pregnant women on how to avoid contracting toxoplasmosis, and educating physicians on making the best use of reference laboratories before major treatment decisions are made. Further research to reevaluate the literature critically, review new treatment regimens and examine costs and benefits of screening and treatment of toxoplasmosis in pregnancy, bringing together European and American researchers, is needed.^

Functional data analysis approaches for genotype-phenotype association studies from next-generation sequencing

Next-generation DNA sequencing platforms can effectively detect the entire spectrum of genomic variation and is emerging to be a major tool for systematic exploration of the universe of variants and interactions in the entire genome. However, the data produced by next-generation sequencing technologies will suffer from three basic problems: sequence errors, assembly errors, and missing data. Current statistical methods for genetic analysis are well suited for detecting the association of common variants, but are less suitable to rare variants. This raises great challenge for sequence-based genetic studies of complex diseases.^ This research dissertation utilized genome continuum model as a general principle, and stochastic calculus and functional data analysis as tools for developing novel and powerful statistical methods for next generation of association studies of both qualitative and quantitative traits in the context of sequencing data, which finally lead to shifting the paradigm of association analysis from the current locus-by-locus analysis to collectively analyzing genome regions.^ In this project, the functional principal component (FPC) methods coupled with high-dimensional data reduction techniques will be used to develop novel and powerful methods for testing the associations of the entire spectrum of genetic variation within a segment of genome or a gene regardless of whether the variants are common or rare.^ The classical quantitative genetics suffer from high type I error rates and low power for rare variants. To overcome these limitations for resequencing data, this project used functional linear models with scalar response to develop statistics for identifying quantitative trait loci (QTLs) for both common and rare variants. To illustrate their applications, the functional linear models were applied to five quantitative traits in Framingham heart studies. ^ This project proposed a novel concept of gene-gene co-association in which a gene or a genomic region is taken as a unit of association analysis and used stochastic calculus to develop a unified framework for testing the association of multiple genes or genomic regions for both common and rare alleles. The proposed methods were applied to gene-gene co-association analysis of psoriasis in two independent GWAS datasets which led to discovery of networks significantly associated with psoriasis.^

The Comprehensive Assessment of Leadership for Learning: A Next Generation Formative Evaluation and Feedback System

Recent developments in federal policy have prompted the creation of state evaluation frameworks for principals and teachers that hold educators accountable for effective practices and student outcomes. These changes have created a demand for formative evaluation instruments that reflect current accountability pressures and can be used by schools to focus school improvement and leadership development efforts. The Comprehensive Assessment of Leadership for Learning (CALL) is a next generation, 360-degree on-line assessment and feedback system that reflect best practices in feedback design. Some unique characteristics of CALL include a focus on: leadership distributed throughout the school rather than as carried out by an individual leader; assessment of leadership tasks rather than perceptions of leadership practice; a focus on larger complex systems of middle and high school; and transparency of assessment design. This paper describes research contributing to the design and validation of the CALL survey instrument.

The nitrogen costs of photosynthesis in a diatom under current and future pCO2

With each cellular generation, oxygenic photoautotrophs must accumulate abundant protein complexes that mediate light capture, photosynthetic electron transport and carbon fixation. In addition to this net synthesis, oxygenic photoautotrophs must counter the light-dependent photoinactivation of Photosystem II (PSII), using metabolically expensive proteolysis, disassembly, resynthesis and re-assembly of protein subunits. We used growth rates, elemental analyses and protein quantitations to estimate the nitrogen (N) metabolism costs to both accumulate the photosynthetic system and to maintain PSII function in the diatom Thalassiosira pseudonana, growing at two pCO2 levels across a range of light levels. The photosynthetic system contains c. 15-25% of total cellular N. Under low growth light, N (re)cycling through PSII repair is only c. 1% of the cellular N assimilation rate. As growth light increases to inhibitory levels, N metabolite cycling through PSII repair increases to c. 14% of the cellular N assimilation rate. Cells growing under the assumed future 750 ppmv pCO2 show higher growth rates under optimal light, coinciding with a lowered N metabolic cost to maintain photosynthesis, but then suffer greater photoinhibition of growth under excess light, coincident with rising costs to maintain photosynthesis. We predict this quantitative trait response to light will vary across taxa.

Policies and Education in Latin America : From the 'competitive quality' to 'quality for the generation of bicentenary'

En América Latina la injerencia de los organismos internacionales en la política nacional constituye un fenómeno que no se puede soslayar. Se trata de una cuestión candente en el contexto actual y remite a la presencia creciente en los países de la región de una serie de papers, documentos, boletines que, generados en el seno de dichas entidades, señalan desafíos presentes y futuros que deberá atender América Latina. En el campo educativo, marcan las orientaciones de política para la región y representan discursos sobre la educación que es menester analizar críticamente. El objetivo de este trabajo es analizar una serie de ideas, recomendaciones y retóricas político-pedagógicas de los Organismos Internacionales respecto de la denominada calidad de la educación en América Latina con la intención de poner de manifiesto su productividad discursiva en tanto su incidencia está ligada a significantes que operan ordenando las disputas político-discursivas del campo educativo

Policies and Education in Latin America : From the 'competitive quality' to 'quality for the generation of bicentenary'

En América Latina la injerencia de los organismos internacionales en la política nacional constituye un fenómeno que no se puede soslayar. Se trata de una cuestión candente en el contexto actual y remite a la presencia creciente en los países de la región de una serie de papers, documentos, boletines que, generados en el seno de dichas entidades, señalan desafíos presentes y futuros que deberá atender América Latina. En el campo educativo, marcan las orientaciones de política para la región y representan discursos sobre la educación que es menester analizar críticamente. El objetivo de este trabajo es analizar una serie de ideas, recomendaciones y retóricas político-pedagógicas de los Organismos Internacionales respecto de la denominada calidad de la educación en América Latina con la intención de poner de manifiesto su productividad discursiva en tanto su incidencia está ligada a significantes que operan ordenando las disputas político-discursivas del campo educativo

Policies and Education in Latin America : From the 'competitive quality' to 'quality for the generation of bicentenary'

En América Latina la injerencia de los organismos internacionales en la política nacional constituye un fenómeno que no se puede soslayar. Se trata de una cuestión candente en el contexto actual y remite a la presencia creciente en los países de la región de una serie de papers, documentos, boletines que, generados en el seno de dichas entidades, señalan desafíos presentes y futuros que deberá atender América Latina. En el campo educativo, marcan las orientaciones de política para la región y representan discursos sobre la educación que es menester analizar críticamente. El objetivo de este trabajo es analizar una serie de ideas, recomendaciones y retóricas político-pedagógicas de los Organismos Internacionales respecto de la denominada calidad de la educación en América Latina con la intención de poner de manifiesto su productividad discursiva en tanto su incidencia está ligada a significantes que operan ordenando las disputas político-discursivas del campo educativo

Measurements of ocean microstructure, physical oceanography and current in the Weddell Sea, Antarctica, during the RRS Ernest Shackleton cruises ES033 and ES060

Turbulence profile measurements made on the upper continental slope and shelf of the southeastern Weddell Sea reveal striking contrasts in dissipation and mixing rates between the two sites. The mean profiles of dissipation rates from the upper slope are 1-2 orders of magnitude greater than the profiles collected over the shelf in the entire water column. The difference increases toward the bottom where the dissipation rate of turbulent kinetic energy and the vertical eddy diffusivity on the slope exceed 10?7 W kg?1 and 10?2 m2 s?1, respectively. Elevated levels of turbulence on the slope are concentrated within a 100 m thick bottom layer, which is absent on the shelf. The upper slope is characterized by near-critical slopes and is in close proximity to the critical latitude for semidiurnal internal tides. Our observations suggest that the upper continental slope of the southern Weddell Sea is a generation site of semidiurnal internal tide, which is trapped along the slope along the critical latitude, and dissipates its energy in a inline image m thick layer near the bottom and within inline image km across the slope.

Next Generation of Energy Residential Gateways for Demand Response and Dynamic Pricing

Predictions about electric energy needs, based on current electric energy models, forecast that the global energy consumption on Earth for 2050 will double present rates. Using distributed procedures for control and integration, the expected needs can be halved. Therefore implementation of Smart Grids is necessary. Interaction between final consumers and utilities is a key factor of future Smart Grids. This interaction is aimed to reach efficient and responsible energy consumption. Energy Residential Gateways (ERG) are new in-building devices that will govern the communication between user and utility and will control electric loads. Utilities will offer new services empowering residential customers to lower their electric bill. Some of these services are Smart Metering, Demand Response and Dynamic Pricing. This paper presents a practical development of an ERG for residential buildings.

Development of a grid connected micro wind generator. A practical activity for the course on electric generation with wind energy

This paper describes a practical activity, part of the renewable energy course where the students have to build their own complete wind generation system, including blades, PM-generator, power electronics and control. After connecting the system to the electric grid the system has been tested during real wind scenarios. The paper will describe the electric part of the work surface-mounted permanent magnet machine design criteria as well as the power electronics part for the power control and the grid connection. A Kalman filter is used for the voltage phase estimation and current commands obtained in order to control active and reactive power. The connection to the grid has been done and active and reactive power has been measured in the system.

Methodology for automated generation of multiple choice questions in self assessment

Current trends in the European Higher Education Area (EHEA) are moving towards the continuous evaluation of the students in substitution of the traditional evaluation based on a single test or exam. This fact and the increase in the number of students during last years in Engineering Schools, requires to modify evaluation procedures making them compatible with the educational and research activities. This work presents a methodology for the automatic generation of questions. These questions can be used as self assessment questions by the student and/or as queries by the teacher. The proposed approach is based on the utilization of parametric questions, formulated as multiple choice questions and generated and supported by the utilization of common programs of data sheets and word processors. Through this approach, every teacher can apply the proposed methodology without the use of programs or tools different from those normally used in his/her daily activity

Power system stability of a small sized isolated network supplied by a combined wind-pumped storage generation system: a case study in the Canary Islands

Massive integration of renewable energy sources in electrical power systems of remote islands is a subject of current interest. The increasing cost of fossil fuels, transport costs to isolated sites and environmental concerns constitute a serious drawback to the use of conventional fossil fuel plants. In a weak electrical grid, as it is typical on an island, if a large amount of conventional generation is substituted by renewable energy sources, power system safety and stability can be compromised, in the case of large grid disturbances. In this work, a model for transient stability analysis of an isolated electrical grid exclusively fed from a combination of renewable energy sources has been studied. This new generation model will be installed in El Hierro Island, in Spain. Additionally, an operation strategy to coordinate the generation units (wind, hydro) is also established. Attention is given to the assessment of inertial energy and reactive current to guarantee power system stability against large disturbances. The effectiveness of the proposed strategy is shown by means of simulation results.