42 research outputs found
Modular microfluidic system as a model of cystic fibrosis airways
A modular microfluidic airways model system that can simulate the changes in oxygen tension in different compartments of the cystic fibrosis (CF) airways was designed, developed, and tested. The fully reconfigurable system composed of modules with different functionalities: multichannel peristaltic pumps, bubble traps, gas exchange chip, and cell culture chambers. We have successfully applied this system for studying the antibiotic therapy of Pseudomonas aeruginosa, the bacteria mainly responsible for morbidity and mortality in cystic fibrosis, in different oxygen environments. Furthermore, we have mimicked the bacterial reinoculation of the aerobic compartments (lower respiratory tract) from the anaerobic compartments (cystic fibrosis sinuses) following an antibiotic treatment. This effect is hypothesised as the one on the main reasons for recurrent lung infections in cystic fibrosis patients
Direct immobilization of DNA probes on non-modified plastics by UV irradiation and integration in microfluidic devices for rapid bioassay
DNA microarrays have become one of the most powerful tools in the field of genomics and medical diagnosis. Recently, there has been increased interest in combining microfluidics with microarrays since this approach offers advantages in terms of portability, reduced analysis time, low consumption of reagents, and increased system integration. Polymers are widely used for microfluidic systems, but fabrication of microarrays on such materials often requires complicated chemical surface modifications, which hinders the integration of microarrays into microfluidic systems. In this paper, we demonstrate that simple UV irradiation can be used to directly immobilize poly(T)poly(C)-tagged DNA oligonucleotide probes on many different types of plastics without any surface modification. On average, five- and fourfold improvement in immobilization and hybridization efficiency have been achieved compared to surface-modified slides with aminated DNA probes. Moreover, the TC tag only costs 30% of the commonly used amino group modifications. Using this microarray fabrication technique, a portable cyclic olefin copolymer biochip containing eight individually addressable microfluidic channels was developed and used for rapid and parallel identification of Avian Influenza Virus by DNA hybridization. The one-step, cost-effective DNA-linking method on non-modified polymers significantly simplifies microarray fabrication procedures and permits great flexibility to plastic material selection, thus making it convenient to integrate microarrays into plastic microfluidic systems
The concept of "compartment allergy": prilocaine injected into different skin layers
We herein present a patient with delayed-type allergic hypersensitivity against prilocaine leading to spreading eczematous dermatitis after subcutaneous injections for local anesthesia with prilocaine. Prilocaine allergy was proven by positive skin testing and subcutaneous provocation, whereas the evaluation of other local anesthetics - among them lidocaine, articaine and mepivacaine - did not exhibit any evidence for cross-reactivity
One-Step FE Model Updating Using Local Correspondence and Mode Shape Orthogonality
In this paper, it is described how the matrix mixing model updating technique can be combined with the local correspondence (LC) mode shape expansion algorithm, to give a new finite element (FE) model updating method. The matrix mixing method uses that the inverse mass and stiffness matrices can be expressed as a linear combination of outer products of FE mode shape vectors, where the low-frequency part of these sums are substituted with expanded test modes. The approach is meant to update FE models in one-step and is exact, except for the following two approximations: the mode shape smoothing and the mass scaling of the expanded experimental mode shapes. A simulation study illustrates the errors from the two approximations and shows the ability of the technique to improve the modal assurance criterion (MAC) values so that they get very close to unity. Finally, the performance of the proposed updating method is assessed by means of an application example in which the FE model is updated based on the test modes of a real structure
The role of Chlamydiales in adverse pregnancy outcome : a community-based nested case-control study
Objectives: Over the last decades, the Chlamydiales order has expanded and a new group of Chlamydia-related bacteria has emerged, covering species such as Waddlia chondrophila associated with bovine abortion. However, it is unknown whether they compromise human reproduction such as Chlamydia trachomatis. We therefore aimed to investigate the association between vaginal colonization of selected species of the Chlamydiales order with spontaneous abortion, preterm birth, and animal exposure. Methods: Pregnant women were enrolled at the nuchal translucency scan or when admitted for suspected miscarriage at Aarhus University Hospital, Denmark. Cases were defined as spontaneous abortion <22 weeks and preterm birth <37 weeks. Controls were defined as term birth ≥37 weeks. Vaginal samples from 1203 women were assessed using C. trachomatis, W. chondrophila, and pan-Chlamydiales–specific real-time PCRs targeting the 16S rRNA gene. Results: A total of 1120 women of primarily Caucasian ancestry were enrolled, including 193 spontaneous abortions, 88 preterm births, and 839 term births. After sequencing for verification, the prevalence of Chlamydiales was 3 of 193 (1.6%; 95% CI, 0.5–4.8) in women experiencing spontaneous abortion, 2 of 88 (2.3%; 95% CI, 0.6–8.9) in women with preterm birth, and 20 of 839 (2.4%; 95% CI, 1.6–3.7) in women giving birth at term. Thus, Chlamydiales infection was neither significantly associated with spontaneous abortion (OR, 0.68; 95% CI, 0.15–2.01) nor preterm birth (OR, 1.02; 95% CI, 0.15–3.60) compared with women giving birth at term. Amplicons from the pan-Chlamydiales assay revealed close sequence homology and were primarily identified as uncultured Chlamydiales bacteria. Discussion: Among Danish pregnant women, the prevalence of Chlamydiales was low and not associated with adverse pregnancy outcomes
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Performance of stainless steel interconnects with (Mn,Co)3O4-Based coating for solid oxide electrolysis
Mixed transition-metal oxide coatings are commonly applied to stainless steel interconnects for solid oxide cell stacks. Such coatings reduce oxidation and Cr evaporation rates, leading to improved degradation rate and stack lifetime. Here, the ChromLok™ MCO-based composition (Mn,Co)3O4 is applied to Crofer 22 APU stainless steel and evaluated specifically for application in solid oxide electrolyzer stacks operating around 800 °C and utilizing oxygen-ion-conducting solid oxide cells. The MCO coating is found to decrease the stainless steel oxidation rate by about one order of magnitude, and decrease the Cr evaporation rate by fourfold. The coating also dramatically lowers the rate of area-specific resistance increase for stainless steel coupons oxidized for 500 h with constant current applied, from 33 mΩ∗cm2 kh−1 for an uncoated coupon to less than 4 mΩ∗cm2 kh−1 for coated coupons. The coating is demonstrated on full-scale interconnects for single-cells, where the coating dramatically reduces degradation rate, and for a stack, which displays stable operation for 700 h
Was ist ein typischer Arbeiter? Stereotype über soziale Schichten
Akteure nehmen in Interaktionen immer wieder soziale Kategorisierungen von anderen Personen vor und aktivieren die entsprechenden Stereotypen über diese Kategorien. Sowohl in der Sozialpsychologie als auch in der Soziologie fokussiert allerdings die Forschung auf die Untersuchung askriptiver Sozialkategorien, während Konzepte wie Klasse und Schicht weitgehend ausgeblendet bleiben. In diesem Aufsatz wird argumentiert, dass diese Kategorien in der Bevölkerung weithin bekannt und mental zugänglich sind sowie in entsprechenden Situationen auch aktiviert werden. Damit sind sie auch für die Orientierung in alltäglichen Interaktionssituationen relevant. Auf der Grundlage einer Onlineumfrage wird demonstriert, dass die Stereotypkontraste zwischen verschiedenen sozialen Schichten vor allem durch sozioökonomische Merkmale sowie durch hochkulturelle Lebensstilmerkmale bestimmt werden, während Persönlichkeitsmerkmale eine geringere Bedeutung aufweisen