Determination of islet cell antibodies using an ELISA system with a preparation of rat insulinoma (RIN A2) cells

An enzyme-linked immunosorbent assay (ELISA) was established for the detection of islet cell antibodies in human sera. The antigen was prepared from rat insulinoma (RIN A2) cells. Cells were dissociated in lysis buffer and the lysate was centrifuged at 100,000 x g. The supernatant was used to coat microtiter ELISA plates (10 micrograms protein/ml in PBS pH 7.2). Non-specific binding sites on the plates were blocked with 2% PBS-BSA. Human test sera were preabsorbed on separate plates using 2% PBS-BSA and incubated on precoated plates at an optimal dilution of 1/10 in 60 mM PBS for 60 min at 37 degrees C. Phosphatase-labeled anti-human IgG serum and phosphatase substrate were applied and the reaction was stopped by adding 3 M NaOH. Out of 90 sera from type I diabetic patients, 47 (52.2%) reacted in the new ELISA whereas none of 15 type II diabetics, 50 sera containing non-islet specific antibodies or 100 normal controls were positive. In the same group of patients, ICA were positive in 63.3%. When both, the ELISA and conventional ICA testing were applied, the number of positives was increased to 83%. The ICA-ELISA with the above described antigen preparation provides a well standardized and reproducible test method which is highly specific for type I diabetes. It may therefore be useful for large screening procedures

Validation of an automated enzyme immunoassay for interleukin-6 for routine clinical use

Serum levels of Interleukin-6 (IL-6), a proinflammatory cytokine, are increased in early stages of inflammatory diseases such as infection and sepsis. Assay systems which permit its measurement within a few hours and as a single measurement have not been reported so far. We therefore evaluated a now commercially available automated method for IL-6 measurement on the Cobas Core(R) immunological analyzer (Roche Diagnostic Systems) which enables single IL-6 measurement within about 1 hour. The automated assay correlates well with an established, manual microtiter plate assay (Biosource GmbH) which uses the same antibodies and reagents (r=0.98). Accuracy of the automated method was established by adding known amounts of IL-6 international reference preparation. Recovery of the international standard was in the range of 92-104%. The automated assay had a precision of singletons below 6% and was linear up to 2800 pg/ml. This automated assay provides a suitable, convenient and time saving method for measurement of IL-6 serum levels in the routine clinical laboratory

Noncontact atomic force microscopy simulator with phase-locked-loop controlled frequency detection and excitation

A simulation of an atomic force microscope operating in the constant amplitude dynamic mode is described. The implementation mimics the electronics of a real setup including a digital phase-locked loop (PLL). The PLL is not only used as a very sensitive frequency detector, but also to generate the time-dependent phase shifted signal driving the cantilever. The optimum adjustments of individual functional blocks and their joint performance in typical experiments are determined in detail. Prior to testing the complete setup, the performances of the numerical PLL and of the amplitude controller were ascertained to be satisfactory compared to those of the real components. Attention is also focused on the issue of apparent dissipation, that is, of spurious variations in the driving amplitude caused by the nonlinear interaction occurring between the tip and the surface and by the finite response times of the various controllers. To do so, an estimate of the minimum dissipated energy that is detectable by the instrument upon operating conditions is given. This allows us to discuss the relevance of apparent dissipation that can be conditionally generated with the simulator in comparison to values reported experimentally. The analysis emphasizes that apparent dissipation can contribute to the measured dissipation up to 15% of the intrinsic dissipated energy of the cantilever interacting with the surface, but can be made negligible when properly adjusting the controllers, the PLL gains and the scan speed. It is inferred that the experimental values of dissipation usually reported in the literature cannot only originate in apparent dissipation, which favors the hypothesis of "physical" channels of dissipation

HotCity—A Gamified Token System for Reporting Waste Heat Sources

Urban planning needs to discover and incorporate new energy sources to meet climate protection targets in the future. Waste heat from industrial and urban infrastructure has proven to be a viable solution, but its proper identification can be challenging, especially for smaller and unconventional sources. Our project relies on the principles of gamification enhanced by a blockchain based token system and crowdsourcing as methods to collect and utilise spatial data such as the location and the size of previously unused heat sources. The mobile platform-neutral HotCity App en ables users to collectively patrol the city in search of waste heat sources and to gain tokens that can be exchanged for rewards. The blockchain platform Ardor was used for cheat proofing and to enable transparency for the reward system. The field test conducted in winter 2020/2021 showed high usability scores as well as high acceptance ratings of our approach opening up new use case scenarios in the context of spatial energy planning.©2022 Elsevier. This manuscript version is made available under the Creative Commons Attribution–NonCommercial–NoDerivatives 4.0 International (CC BY–NC–ND 4.0) license, https://creativecommons.org/licenses/by-nc-nd/4.0/fi=vertaisarvioitu|en=peerReviewed

Behavioral Responses to Uncertainty in Weight-Restored Anorexia Nervosa – Preliminary Results

Impaired decision-making under conditions of uncertainty seems to contribute to theexpression and maintenance of anorexia nervosa (AN), but it is not clear whether thisimpairment is a disease state that would remit with treatment, or a persisting trait inpatients with AN. To examine this question, a longitudinal study was conducted in12 female inpatients with AN (age M = 22.2, SE = 1.36), before (Time-1) and afterreaching a body mass index of >17.5 kg/m2 (Time-2). Intolerance of uncertainty (IU)was assessed via a decision-making task, the wheel of fortune (WOF). Weight gain atTime-2 was accompanied with significant changes in uncertainty-related performancecompared to Time-1 [(Time Uncertainty), p < 0.05]. At Time-1, reaction times (RTs)varied in function of uncertainty, while at Time-2, uncertainty did not modulate RTs.These findings support a change in decision-making under uncertainty with successfulweight-rehabilitation in AN. While IU was present in underweight patients, it becamenon-significant after weight restoration

Materials Pushing the Application Limits of Wire Grid Polarizers further into the Deep Ultraviolet Spectral Range

Wire grid polarizers (WGPs), periodic nano-optical meta-surfaces, are convenient polarizing elements for many optical applications. However, they are still inadequate in the deep ultraviolet spectral range. We show that to achieve high performance ultraviolet WGPs a material with large absolute value of the complex permittivity and extinction coefficient at the wavelength of interest has to be utilized. This requirement is compared to refractive index models considering intraband and interband absorption processes. We elucidate why the extinction ratio of metallic WGPs intrinsically humble in the deep ultraviolet, whereas wide bandgap semiconductors are superior material candidates in this spectral range. To demonstrate this, we present the design, fabrication and optical characterization of a titanium dioxide WGP. At a wavelength of 193 nm an unprecedented extinction ratio of 384 and a transmittance of 10 % is achieved.Comment: 21 pages, Advanced Optical Materials 201

Geduld von Vorschulkindern : Ergebnisse einer Experimentalstudie im Haushaltskontext von Kindern

In dieser Studie werden anhand einer experimentellen Datenerhebung im Rahmen der deutschen Längsschnittstudie Sozio-oekonomisches Panel (SOEP) mögliche Determinanten des Belohnungsaufschubs im Alter von fünf bis sechs Jahren untersucht (im Folgenden als „Geduld bei Kindern“ bezeichnet). Unsere Ergebnisse verdeutlichen, dass mit ansteigendem Alter bei den jüngeren Kindern die Geduld zunimmt und bessere verbale Fähigkeiten und Geduld positiv miteinander korreliert sind. Freilich weisen das Geschlecht, die Anzahl Kinder im Haushalt, das Haushaltseinkommen sowie der Besuch einer Bildungseinrichtung keinen Zusammenhang mit der Geduld auf. Jedoch deuten die Ergebnisse darauf hin, dass eine geduldigere Mutter sowie eine längere Stilldauer im Säuglingsalter die Wahrscheinlichkeit geduldig zu sein erhöht. Geduld als Basis für Lebenserfolg ist damit nicht nur eine Frage der Biologie und Vererbung, sondern die frühe Gen-Umwelt-Interaktion, nämlich die Eltern-Kind-Interaktion und frühkindliche Sozialisation, scheint demnach auch im Bereich der Zeitpräferenz die „Wiege des Handelns“ zu sein

Optimization of tube voltage in X-ray dark-field chest radiography

Grating-based X-ray dark-field imaging is a novel imaging modality which has been refined during the last decade. It exploits the wave-like behaviour of X-radiation and can nowadays be implemented with existing X-ray tubes used in clinical applications. The method is based on the detection of small-angle X-ray scattering, which occurs e.g. at air-tissue-interfaces in the lung or bone-fat interfaces in spongy bone. In contrast to attenuation-based chest X-ray imaging, the optimal tube voltage for dark-field imaging of the thorax has not yet been examined. In this work, dark-field scans with tube voltages ranging from 60 to 120 kVp were performed on a deceased human body. We analyzed the resulting images with respect to subjective and objective image quality, and found that the optimum tube voltage for dark-field thorax imaging at the used setup is at rather low energies of around 60 to 70 kVp. Furthermore, we found that at these tube voltages, the transmission radiographs still exhibit sufficient image quality to correlate dark-field information. Therefore, this study may serve as an important guideline for the development of clinical dark-field chest X-ray imaging devices for future routine use