94 research outputs found

    Assembly of a polymer lab-on-chip device for impedimetric measurements of D-dimers in whole blood

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    This paper reports the development and characterisation of an assembly technology for a polymer lab-on-chip. The system consists of a 150 m deep hot embossed microfluidic channel in polycarbonate and Au electrodes fabricated separately by photolithography on polyethylenenaphthalate. The system is designed for impedimetric immunoassay detection in whole blood. Electrode layer and microfluidic substrate are joined by means of a 50 m thick double-sided medical grade adhesive tape, adjusted with an optical alignment system. The bond proved to be liquid tight at room temperature. An alignment accuracy of 34 m (+/- 19 m) evaluated over a set of 23 samples, was achieved. The effect of alignment accuracy of the intermediate adhesive film on whole blood flow properties in the device is studied. Already an alignment error of 70 m increases the flushing out time of whole blood by approximately 20 %

    Influence of permanent night work on the circadian rhythm of blood pressure

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    Abstract. Night workers exercise their labours activities and rest in contrary schedules to the chronobiological standards. This inversion leads the body to several adaptations, including changes in the circadian rhythm of blood pressure (BP). Objectives: To evaluate the BP in individuals who perform work at night, in order to objectively detail the BP circadian rhythm adaptations infixed night workers. Methods: A cross-sectional study enrolling 23 fixed night workers, both genders, was performed, with 24h BP measured with ambulatory blood pressure monitoring (ABPM) during a normal working day. Risk factors, anthropometric and lifestyle information were collected using a standard questionnaire. Results: Ambulatory BP demonstrated a pattern of adaptation to the sleep/activity cycle in all participants. BP dropped during the sleeping period (mean drop: -11.35±6.85) and was higher during the awakening period, reaching the highest results and greater BP variability during the working period. The chronobiological adaptation of the 24h BP was not dependent on sociodemographic or clinical characteristics. In addition, age, male gender, obesity, and those working less time were associated with higher BP mean values. Conclu-sions: The circadian rhythm of BP follows the working circadian profile of the individual.info:eu-repo/semantics/publishedVersio

    A Geologically Based Indoor-Radon Potential Map of Kentucky

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    We combined 71,930 short-term (median duration 4 days) home radon test results with 1:24,000-scale bedrock geologic map coverage of Kentucky to produce a statewide geologically based indoor-radon potential map. The test results were positively skewed with a mean of 266 Bq/m3, median of 122 Bq/m3, and 75th percentile of 289 Bq/m3. We identified 106 formations with ≥10 test results. Analysis of results from 20 predominantly monolithologic formations showed indoor-radon concentrations to be positively skewed on a formation-by-formation basis, with a proportional relationship between sample means and standard deviations. Limestone (median 170 Bq/m3) and dolostone (median 130 Bq/m3) tended to have higher indoor-radon concentrations than siltstones and sandstones (median 67 Bq/m3) or unlithified surficial deposits (median 63 Bq/m3). Individual shales had median values ranging from 67 to 189 Bq/m3; the median value for all shale values was 85 Bq/m3. Percentages of values falling above the U.S. Environmental Protection Agency (EPA) action level of 148 Bq/m3 were sandstone and siltstone: 24%, unlithified clastic: 21%, dolostone: 46%, limestone: 55%, and shale: 34%. Mississippian limestones, Ordovician limestones, and Devonian black shales had the highest indoor-radon potential values in Kentucky. Indoor-radon test mean values for the selected formations were also weakly, but statistically significantly, correlated with mean aeroradiometric uranium concentrations. To produce a map useful to nonspecialists, we classified each of the 106 formations into five radon-geologic classes on the basis of their 75th percentile radon concentrations. The statewide map is freely available through an interactive internet map service

    Respirable crystalline silica and lung cancer in community-based studies: impact of job-exposure matrix specifications on exposure–response relationships

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    Objectives: The quantitative job-exposure matrix SYN-JEM consists of various dimensions: job-specific estimates, region-specific estimates, and prior expert ratings of jobs by the semi-quantitative DOM-JEM. We analyzed the effect of different JEM dimensions on the exposure-response relationships between occupational silica exposure and lung cancer risk to investigate how these variations influence estimates of exposure by a quantitative JEM and associated health endpoints. Methods: Using SYN-JEM, and alternative SYN-JEM specifications with varying dimensions included, cumulative silica exposure estimates were assigned to 16 901 lung cancer cases and 20 965 controls pooled from 14 international community-based case-control studies. Exposure-response relationships based on SYN-JEM and alternative SYN-JEM specifications were analyzed using regression analyses (by quartiles and log-transformed continuous silica exposure) and generalized additive models (GAM), adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk. Results: SYN-JEM and alternative specifications generated overall elevated and similar lung cancer odds ratios ranging from 1.13 (1st quartile) to 1.50 (4th quartile). In the categorical and log-linear analyses SYN-JEM with all dimensions included yielded the best model fit, and exclusion of job-specific estimates from SYN-JEM yielded the poorest model fit. Additionally, GAM showed the poorest model fit when excluding job-specific estimates. Conclusion: The established exposure-response relationship between occupational silica exposure and lung cancer was marginally influenced by varying the dimensions of SYN-JEM. Optimized modelling of exposure-response relationships will be obtained when incorporating all relevant dimensions, namely prior rating, job, time, and region. Quantitative job-specific estimates appeared to be the most prominent dimension for this general population JEM

    The "Persuadable Middle" on Same-Sex Marriage: Formative Research to Build Support among Heterosexual College Students

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    Same-sex marriage is a controversial policy issue that affects the welfare of gay and lesbian couples throughout the USA. Considerable research examines opinions about same-sex marriage; however, studies have not investigated the covariates of the “persuadable middle”— those individuals who are neutral or unsure about their views. This group of people is often the target of same-sex marriage campaigns, yet they have received no empirical attention.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89607/1/Woodford et al 2011 Persuadable Middle.pd

    Area deprivation and its association with health in a cross-sectional study: are the results biased by recent migration?

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    <p>Abstract</p> <p>Background</p> <p>The association between area deprivation and health has mostly been examined in cross-sectional studies or prospective studies with short follow-up. These studies have rarely taken migration into account. This is a possible source of misclassification of exposure, i.e. an unknown number of study participants are attributed an exposure of area deprivation that they may have experienced too short for it to have any influence. The aim of this article was to examine to what extent associations between area deprivation and health outcomes were biased by recent migration.</p> <p>Methods</p> <p>Based on data from the Oslo Health Study, a cross-sectional study conducted in 2000 in Oslo, Norway, we used six health outcomes (self rated health, mental health, coronary heart disease, chronic obstructive pulmonary disease, smoking and exercise) and considered migration nine years prior to the study conduct. Migration into Oslo, between the areas of Oslo, and the changes in area deprivation during the period were taken into account. Associations were investigated by multilevel logistic regression analyses.</p> <p>Results</p> <p>After adjustment for individual socio-demographic variables we found significant associations between area deprivation and all health outcomes. Accounting for migration into Oslo and between areas of Oslo did not change these associations much. However, the people who migrated into Oslo were younger and had lower prevalences of unfavourable health outcomes than those who were already living in Oslo. But since they were evenly distributed across the area deprivation quintiles, they had little influence on the associations between area deprivation and health. Evidence of selective migration within Oslo was weak, as both moving up and down in the deprivation hierarchy was associated with significantly worse health than not moving.</p> <p>Conclusion</p> <p>We have documented significant associations between area deprivation and health outcomes in Oslo after adjustment for socio-demographic variables in a cross-sectional study. These associations were weakly biased by recent migration. From our results it still appears that migration prior to study conduct may be relevant to investigate even within a relatively short period of time, whereas changes in area deprivation during such a period is of limited interest.</p

    Testosterone Replacement Therapy

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    Male hypogonadism (HG) can be defined according to its etiology as primary (pHG) when caused by any diseases affecting the testes, or as secondary (sHG) when due to a pituitary or hypothalamic dysfunction. Both fertility and testosterone (T) can be theoretically restored in sHG by removing the precipitating cause and/or by appropriate endocrine therapy. Conversely, only T treatment can be offered to patients with pHG. Symptoms and signs are quite similar independent of the underlying causes. Conversely, the phenotype of the hypogonadal patient is more often affected by the age of hypogonadism onset. Late-onset hypogonadism (LOH) that occurs in adulthood is probably the most common form of HG. In this chapter, the criteria defining LOH and the available T formulations along with their outcomes and main important side effects are analyzed in detail

    An integrated all foil based micro device for point of care diagnostic applications

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    Point-of-Care (POC) diagnostics often fail to meet the market requirements of low cost and advanced functionality, and are often limited to lateral flow based serological diagnostics with reduced sensitivity and specificity. We report here on an integrated microfluidic absorbance measurement device fabricated by roll-to-roll (R2R) compatible manufacturing processes, suitable for low cost POC systems. It is a device exclusively made of foils and takes external light from a low cost LED and converts the point light source to a homogeneous light via a foil based optical filter at the bottom of the device. The light is converted to an electrical signal by an amorphous organic semiconductor (OSC) material, integrated with screen-printed carbon finger on top of the device for electrical measurement. As a proof of principle, we demonstrate DNA hybridization assay, where the target DNA is coupled to magnetic beads for absorbance measurement. The device successfully distinguishes between matched and mismatched DNA hybridization and can differentiate between 1 μM, 50 nM and 2.5 nM DNA target concentrations. The inherent characteristics of the substrates and R2R fabrication concept significantly reduce the cost, making it suitable for POC applications at resource-limited settings

    Destruction of dextran-coated target cells by normal human lymphocytes and monocytes. Induction by a human anti-dextran serum with IgG antibodies restricted to the IgG2 subclass.

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    A human anti-dextran serum, EAK, with IgG antibodies restricted to subclass IgG2, was tested for its capacity to induce lysis of dextran-coated chicken erythrocytes by normal human lymphocytes or monocytes. Another human anti-dextran serum, RGM, with most antibodies belonging to sublass IgG1, and a hyperimmune rabbit anti-dextran serum were used for reference. In lymphocyte-mediated erythrolysis, serum EAK gave rise to 51-Cr release varying from 20% to 80% in different experiments. The hyperimmune rabbit serum was 100 to 1000 times more active, whereas serum RGM was consistently negative. These results correlated well with the concentration of anti-dextran antibodies in these sera. In monocyte-mediated erythrolysis serum EAK had a somewhat higher titer than in lymphocyte-mediated lysis, and serum RGM had a weak but significant activity at low dilutions. Serum EAK also induced erythrophagocytosis by monocytes. Ultracentrifugation did not significantly decrease the inductive capacity of this serum. The results show that antibodies of human sublass IgG2 are efficient inducers of effector functions in both lymphocytic and monocytic cells. Myeloma proteins of the four IgG subclasses were tested for inhibitory capacity in lymphocyte- or monocyte-mediated erythrolysis. Either serum EAK or the rabbit reference serum was used for induction of erythrolysis. Individual myeloma proteins within and between the subclasses varied considerably in inhibitory power. However, whereas IgG1, IgG2, and IgG3 proteins inhibited lymphocyte-mediated erythrolysis induced by either type of antiserum, the two IgG4 proteins tested were essentially negative. These results suggest a lack of specificity of the Fc receptor for subclasses IgG1, IgG2, and IgG3 in both heterologous and homologous inhibition. In monocyte-mediated erythrolysis, IgG1 and IgG3 were strong inhibitors, whereas inhibition by IgG2 and IgG4 was weak and inconsistent. This pattern was seen regardless of whether and inducing antiserum was of rabbit or human origin. Similar results were obtained in monocyte-induced erythrophagocytosis induced by serum EAK. These and previous results suggest that effector cells of the lymphocytic (K cell) variety have Fc receptors different from those of monocytic cells. However, the basis for the differences observed in the inhibition tests remains to be elucidated
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