197 research outputs found
Teratogenicity and Reactive Oxygen Species after transient embryonic hypoxia : Experimental and clinical evidence with focus on drugs causing failed abortion in humans
Peer reviewe
Sheet-metal press line parameter tuning using a combined DIRECT and Nelder-Mead algorithm
It is a great challenge to obtain an efficient algorithm for global optimisation of nonlinear, nonconvex and high dimensional objective functions. This paper shows how the combination of DIRECT and Nelder-Mead algorithms can improve the efficiency in the parameter tuning of a sheet-metal press line. A combined optimisation algorithm is proposed that determines and utilises all local optimal points from DIRECT algorithm as Nelder-Mead starting points. To reduce the total optimisation time, all Nelder-Mead optimisations can be executed in parallel. Additionally, a Collision Inspection Method is implemented in the simulation model to reduce the evaluation time. Altogether, this results in an industrially useful parameter tuning method. Improvements of an increased production rate of 7% and 40% smoother robot motions have been achieved
Tracking the Small with the Smallest â Using Nanotechnology in Tracking Zooplankton
A major problem when studying behavior and migration of small organisms is that many of the questions addressed for larger animals are not possible to formulate due to constraints on tracking smaller animals. In aquatic ecosystems, this problem is particularly problematic for zoo- and phytoplankton, since tracking devices are too heavy to allow the organism to act naturally. However, recent advances in nanotechnology have made it possible to track individual animals and thereby to focus on important and urgent questions which previously have not been possible to address. Here we report on a novel approach to track movement and migratory behavior of millimeter sized aquatic animals, particularly Daphnia magna, using the commercially available nanometer sized fluorescent probes known as quantum dots. Experimental trials with and without quantum dots showed that they did not affect behavior, reproduction or mortality of the tested animals. Compared to previously used methods to label small animals, the nano-labeling method presented here offers considerable improvements including: 24 h fluorescence, studies in both light and darkness, much improved optical properties, potential to study large volumes and even track animals in semi-natural conditions. Hence, the suggested method, developed in close cooperation between biologists, chemists and physicists, offers new opportunities to routinely study zooplankton responses to light, food and predation, opening up advancements within research areas such as diel vertical/horizontal migration, partial migration and other differences in intra- and interspecific movements and migration
Recognition of depression in people of different cultures: a qualitative study
<p>Abstract</p> <p>Background</p> <p>Many minority group patients who attend primary health care are depressed. To identify a depressive state when GPs see patients from other cultures than their own can be difficult because of cultural and gender differences in expressions and problems of communication. The aim of this study was to explore and analyse how GPs think and deliberate when seeing and treating patients from foreign countries who display potential depressive features.</p> <p>Methods</p> <p>The data were collected in focus groups and through individual interviews with GPs in northern Sweden and analysed by qualitative content analysis.</p> <p>Results</p> <p>In the analysis three themes, based on various categories, emerged; "Realizing the background", "Struggling for clarity" and "Optimizing management". Patients' early life events of importance were often unknown which blurred the accuracy. Reactions to trauma, cultural frictions and conflicts between the new and old gender norms made the diagnostic process difficult. The patient-doctor encounter comprised misconceptions, and social roles in the meetings were sometimes confused. GPs based their judgement mainly on clinical intuition and the established classification of depressive disorders was discussed. Tools for management and adequate action were diffuse.</p> <p>Conclusion</p> <p>Dialogue about patients' illness narratives and social context are crucial. There is a need for tools for multicultural, general practice care in the depressive spectrum. It is also essential to be aware of GPs' own conceptions in order to avoid stereotypes and not to under- or overestimate the occurrence of depressive symptoms</p
Functionalised ZnO-nanorod-based selective electrochemical sensor for intracellular glucose
RECENT DEVELOPMENTS OF BIOSENSORS BASED ON THERMISTORS AND SEMICONDUCTORS
The enzyme thermistor (ET) is a simple flow calorimeter primarily intended
for rapid metabolite assays with use of immobilized enzymes,
but it can be used as a general biocalorimeter as well. The reaction
heat produced in a small column containing immobilized biocatalyst is
measured with a thermistor as a temperature change of the effluent of
the column. The temperature change is linearjvs. the substrate) iconâ
centration over wide ranges from about 1 uM to several hundred mM depending
on the actual enzyme reaction. Considerably higher sensitivities
can be obtained by using recycling enzyme systems. Up to 60 samples
per hour can be analyzed. A large number of metabolite assays of
clinical as well as of biotechnological interest has been studied.
The ET assay can easily be automated and is well suited for monitoring
and control of biotechnological processes due to its high operational
stability. For the monitoring of larger molecules a thermometric enzyme
immunoassay (TELISA) has been developed and automated.
Hydrogen- and ammonia-sensitive semiconductors of Pd-MOS type could be
combined with enzymes and cells into highly sensitive biosensors.
Addition of another catalytic metal, such as Ir on the gate of the MOSdevice
results in enhanced ammonia-sensitivity. Highly sensitive methods
for the determination of e.g. urea and creatinine have been developed.
Detection is made in the gas phase, which is advantageous
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