Search

Cardiac vascular diseases, especially acute myocardial infarction (AMI), are one of the leading causes of death worldwide. Therefore cardio-specific biomarkers such as cardiac troponin I (cTnI) play an essential role in the field of diagnostics. In order to enable rapid and accurate measurement of cTnI with the potential of online measurements, a chemiluminescence-based immunosensor is presented as a proof of concept. A flow cell was designed and combined with a sensitive CMOS camera allowing sensitive optical readout. In addition, a microfluidic setup was established, which achieved selective and quasi-online cTnI determination within ten minutes. The sensor was tested with recombinant cTnI in phosphate buffer and demonstrated cTnI measurements in the concentration range of 2–25 µg/L. With the optimized system, a limit of detection (LoD) of 0.6 µg/L (23 pmol/L) was achieved. Furthermore, the selectivity of the immunosensor was investigated with other recombinant proteins, such as cTnT, and cTnC, at a level of 16 µg/L. No cross-reactivity could be observed. Measurements with diluted blood plasma and serum resulted in an LoD of 60 µg/L (2.4 nmol/L) and 70 µg/L (2.9 nmol/L), respectively.

List experiments are widely used in the social sciences to elicit truthful responses to sensitive questions. Yet, the research design commonly suffers from the problem of measurement error in the form of non-strategic respondent error , where some inattentive participants might provide random responses. This type of error can result in severely biased estimates. A recently proposed solution is the use of a necessarily false placebo item to equalize the length of the treatment and control lists in order to alleviate concerns about respondent error. In this paper we show theoretically that placebo items do not in general eliminate bias caused by non-strategic respondent error. We introduce a new option, the mixed control list, and show how researchers can choose between different control list designs to minimize the problems caused by inattentive respondents. We provide researchers with practical guidance to think carefully about the bias that inattentive respondents might cause in a given application of the list experiment. We also report results from a large novel list experiment fielded to over 4900 respondents, specifically designed to illustrate our theoretical argument and recommendations.

Classifying political regimes has never been more difficult. Most contemporary regimes hold de-jure multiparty elections with universal suffrage. In some countries, elections ensure that political rulers are—at least somewhat—accountable to the electorate whereas in others they are a mere window dressing exercise for authoritarian politics. Hence, regime types need to be distinguished based on the de-facto implementation of democratic institutions and processes. Using V-Dem data, we propose with Regimes of the World (RoW) such an operationalization of four important regime types—closed and electoral autocracies; electoral and liberal democracies—with vast coverage (almost all countries from 1900 to 2016). We also contribute a solution to a fundamental weakness of extant typologies: The unknown extent of misclassification due to uncertainty from measurement error. V-Dem’s measures of uncertainty (Bayesian highest posterior densities) allow us to be the first to provide a regime typology that distinguishes cases classified with a high degree of certainty from those with “upper” and “lower” bounds in each category. Finally, a comparison of disagreements with extant datasets (7%–12% of the country-years), demonstrates that the RoW classification is more conservative, classifying regimes with electoral manipulation and infringements of the political freedoms more frequently as electoral autocracies, suggesting that it better captures the opaqueness of contemporary autocracies.

The study of popular support for authoritarian regimes has long relied on the assumption that respondents provide truthful answers to surveys. However, when measuring regime support in closed political systems there is a distinct risk that individuals are less than forthright due to fear that their opinions may be made known to the public or the authorities. In order to test this assumption, we conducted a novel web-based survey in China in which we included four list experiments of commonly used items in the comparative literature on regime support. We find systematic bias for all four measures; substantially more individuals state that they support the regime with direct questioning than when presented with our indirect list experiments. The level of self-censorship, which ranges from 24.5 to 26.5 percentage points, is considerably higher than previously thought. Self-censorship is further most prevalent among the wealthy, urban, female and younger respondents.

The trafficking of illegal drugs by criminal networks at borders, harbors, or airports is an increasing issue for public health as these routes ensure the main supply of illegal drugs. The prevention of drug smuggling, including the installation of scanners and other analytical devices to detect small traces of drugs within a reasonable time frame, remains a challenge. The presented immunosensor is based on a monolithic affinity column with a large excess of immobilized hapten, which traps fluorescently labeled antibodies as long as the analyte cocaine is absent. In the presence of the drug, some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled complementary metal-oxide-semiconductor (CMOS) camera. Liquid handling is performed with high-precision syringe pumps and microfluidic chip-based mixing devices and flow cells. The biosensor achieved limits of detection of 7 ppt (23 pM) of cocaine with a response time of 90 s and a total assay time below 3 min. With surface wipe sampling, the biosensor was able to detect 300 pg of cocaine. This immunosensor belongs to the most sensitive and fastest detectors for cocaine and offers near-continuous analyte measurement.

New compounds as potential poly(vinyl chloride) plasticizers based on soybean oil and oligoesters of adipic acid and different glycols by one‐pot transesterification are synthesized. In the first step of the plasticizer synthesis oligoesters of adipic acid and diethylene glycol, triethylene glycol, or dipropylene glycol are synthesized, and then in situ in the second step, a defined amount of soybean oil is introduced. By degradation of soybean oil with oligoesters, and transesterification reaction, different compounds are obtained. Their physicochemical properties are determined by NMR, SEC, DSC, TGA, and volatility analyses. The properties of synthesized plasticizers are compared with commercial products: monomeric (DEHP) and aliphatic oligoster of adipic acid and 1,3‐butanediol (H‐1). [ABSTRACT FROM AUTHOR]

The AC75 class, used in the America's Cup, is a hydro-foiling racing sailing yacht powered by a double-skin main sail and a single-skin jib. The boat performance is typically predicted by a Velocity Prediction Program (VPP). The aerodynamics are usually modeled with surrogate models of data points collected either through wind tunnel experiments, numerical simulations, or empirical formulations. Previous work has shown that empirical models are not able to predict accurate performance as the sailors can efficiently control the flying shape of each sail. In addition, the empirical coefficients are limited to traditional sails, not yet available for a double-skin main, neglecting also the hull shape and its influence on the sails airflow. To achieve more realistic results through the inclusion of hull shape with realistic sail geometries and shape ranges, a compromise must be found between total computational effort and physical simplifications. Reynolds Averaged Navier-Stokes (RANS) methods typically provide accurate predictions but come with a high computational effort. Potential flow-based methods, also used by America's Cup teams, are computationally less expensive while showing some limitations at higher angles of attack with flow separation. Due to the high number of simulations required for a surrogate model at the early design stage, a Boundary Element Method (BEM) was considered appropriate for the task in combination with a RANS method for comparison. Results have shown that the BEM is able to predict reasonable forces generated by the single-skin jib and double-skin main. The performance deltas with endplated sails on the hull with attached vortices, comply with expected trends. [ABSTRACT FROM AUTHOR]

Platelet-derived growth factor D (PDGF-D) is the most recently discovered member of the PDGF family. PDGF-D signals through PDGF receptor β, but its biological role remains largely unknown. In contrast to other members of the PDGF family of growth factors, which have been extensively investigated using different knockout approaches in mice, PDGF-D has until now not been characterized by gene inactivation in mice. Here, we present the phenotype of a constitutive Pdgfd knockout mouse model (Pdgfd-/-), carrying a LacZ reporter used to visualize Pdgfd promoter activity. Inactivation of the Pdgfd gene resulted in a mild phenotype in C57BL/6 mice, and the offspring was viable, fertile and generally in good health. We show that Pdgfd reporter gene activity was consistently localized to vascular structures in both postnatal and adult tissues. The expression was predominantly arterial, often localizing to vascular bifurcations. Endothelial cells appeared to be the dominating source for Pdgfd, but reporter gene activity was occasionally also found in subpopulations of mural cells. Tissue-specific analyses of vascular structures revealed that NG2-expressing pericytes of the cardiac vasculature were disorganized in Pdgfd-/- mice. Furthermore, Pdgfd-/- mice also had a slightly elevated blood pressure. In summary, the vascular expression pattern together with morphological changes in NG2-expressing cells, and the increase in blood pressure, support a function for PDGF-D in regulating systemic arterial blood pressure, and suggests a role in maintaining vascular homeostasis.

Despite its known expression in both the vascular endothelium and the lung epithelium, until recently the physiological role of the adhesion receptor Gpr116/ADGRF5 has remained elusive. We generated a new mouse model of constitutive Gpr116 inactivation, with a large genetic deletion encompassing exon 4 to exon 21 of the Gpr116 gene. This model allowed us to confirm recent results defining Gpr116 as necessary regulator of surfactant homeostasis. The loss of Gpr116 provokes an early accumulation of surfactant in the lungs, followed by a massive infiltration of macrophages, and eventually progresses into an emphysema-like pathology. Further analysis of this knockout model revealed cerebral vascular leakage, beginning at around 1.5 months of age. Additionally, endothelial-specific deletion of Gpr116 resulted in a significant increase of the brain vascular leakage. Mice devoid of Gpr116 developed an anatomically normal and largely functional vascular network, surprisingly exhibited an attenuated pathological retinal vascular response in a model of oxygen-induced retinopathy. These data suggest that Gpr116 modulates endothelial properties, a previously unappreciated function despite the pan-vascular expression of this receptor. Our results support the key pulmonary function of Gpr116 and describe a new role in the central nervous system vasculature.