73 research outputs found
Evaluation of an ultrafiltration membrane for the removal of fish viruses and bacteria in aquaculture water
publishedVersio
Nasal responses to elevated temperature and Francisella noatunensis infection in Atlantic cod (Gadus morhua)
We report the histological and transcriptomic changes in the olfactory organ of Atlantic cod exposed to Francisella noatunensis. Experimental infection was performed at either 12oC or 17oC. Infected fish presented the classic gross pathologies of francisellosis. Nasal morpho-phenotypic parameters were not significantly affected by temperature and infection, except for the number of mucus cells in the 12oC group seven weeks after the challenge. A higher number of genes were altered through time in the group reared at 17oC. At termination, the nasal transcriptome of infected fish in both groups was similar to the control. When both infected groups were compared, 754 DEGs were identified, many of which were involved in signalling, defence, transmembrane and enzymatic processes. In conclusion, the study reveals that elevated temperature could trigger responses in the olfactory organ of Atlantic cod and shape the nasal response to F. noatunensis infection.Nasal responses to elevated temperature and Francisella noatunensis infection in Atlantic cod (Gadus morhua)publishedVersio
Additive Manufacturing of Binary NiâTi Shape Memory Alloys Using Electron Beam Powder Bed Fusion: Functional Reversibility Through Minor Alloy Modification and Carbide Formation
Shape memory alloys (SMAs), such as NiâTi, are promising candidates for actuation and damping applications. Although processing of NiâTi bulk materials is challenging, well-established processing routes (i.e. casting, forging, wire drawing, laser cutting) enabled application in several niche applications, e.g. in the medical sector. Additive manufacturing, also referred to as 4D-printing in this case, is known to be highly interesting for the fabrication of SMAs in order to produce near-net-shaped actuators and dampers. The present study investigated the impact of electron beam powder bed fusion (PBF-EB/M) on the functional properties of C-rich Ni50.9Ti49.1 alloy. The results revealed a significant loss of Ni during PBF-EB/M processing. Process microstructure property relationships are discussed in view of the applied master alloy and powder processing route, i.e. vacuum induction-melting inert gas atomization (VIGA). Relatively high amounts of TiC, being already present in the master alloy and powder feedstock, are finely dispersed in the matrix upon PBF-EB/M. This leads to a local change in the chemical composition (depletion of Ti) and a pronounced shift of the transformation temperatures. Despite the high TiC content, superelastic testing revealed a good shape recovery and, thus, a negligible degradation in both, the as-built and the heat-treated state
Evaluation of an ultrafiltration membrane for the removal of fish viruses and bacteria in aquaculture water
Ultrafiltration (UF) membranes are used to successfully remove waterborne virus and bacteria from wastewater and drinking water. However, UF membrane application in aquaculture water treatment is limited. In this study we evaluate the performance of a capillary polyethersulfone UF membrane to remove two benchmark waterborne fish pathogens: i) the infectious pancreatic necrosis virus - IPNV, which is an unenveloped icosahedral virus, and ii) the bacterium Aeromonas salmonicida, which is a Gram-negative, facultative anaerobic bacilli. Moreover, the UF membrane bench-scale unit was tested at two temperatures according to salmonid aquaculture: low (4 - 7°C) and high (16 - 19°C). Sterilised natural seawater was spiked with laboratory cultured pathogens, the water was filtrated, and the membrane permeate collected. Both pathogen solution and permeate were evaluated using a cell culture method to estimate the colony-forming units (CFU/ml) for bacteria presence, a median tissue culture infectious dose (TCID50/ml) assay for virus presence, and real-time quantitative polymerase chain reaction (RT-qPCR) for both bacteria and virus presence. The membrane permeate was negative for both virus and bacteria for all analysis and for both low and high temperatures. The results from this bench-scale study are encouraging for the application of UF membrane technology in aquaculture water treatment to prevent virus and bacteria outbreaks. Further studies should validate this UF membrane technology results in commercial aquaculture conditions
Radiosensitization by BRAF inhibitor therapyâmechanism and frequency of toxicity in melanoma patients
This study shows radiosensitization by BRAF inhibitors in clinical practice and ex vivo by fluorescence in situ hybridization of chromosomal breaks. Nevertheless, radiotherapy with concomitant BRAF inhibitor therapy is feasible with an acceptable increase in toxicity. Vemurafenib is a more potent radiosensitizer than dabrafenib in both the patient study and the ex vivo experiment
Replication and validation of higher order models demonstrated that a summary score for the EORTC QLQ-C30 is robust.
Objective: To further evaluate the higher-order measurement structure of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) questionnaire, with the aim of generating a summary score. Study design and setting: Using pretreatment QLQ-C30 data (N=3,282), we conducted confirmatory factor analyses to test seven previously evaluated higher-order models. We compared the summary score(s) derived from the best performing higher-order model with the original QLQ-C30 scale scores, using tumor stage, performance status and change over time (N=244) as grouping variables. Results: Whereas all models showed acceptable fit, we continued in the interest of parsimony with known-groups validity and responsiveness analyses using a summary score derived from the single higher-order factor model. The validity and responsiveness of this QLQ-C30 Summary Score was equal to, and in many cases superior to the original, underlying QLQ-C30 scale scores. Conclusion: Our results provide empirical support for a measurement model for the QLQ-C30 yielding a single summary score. The availability of this Summary Score can avoid problems with potential Type I errors that arise due to multiple testing when making comparisons based on the 15 outcomes generated by this questionnaire, and may reduce sample size requirements for HRQL studies using the QLQ-C30 questionnaire when an overall summary score is a relevant primary outcome
Numerical study on load-bearing capabilities of beam-like lattice structures with three different unit cells
The design and analysis of lattice structures manufactured using Additive Manufacturing (AM) technique is a new approach to create lightweight high-strength components. However, it is difficult for engineers to choose the proper unit cell for a certain function structure and loading case. In this paper, three beam-like lattice structures with triangular prism, square prism and hexagonal prism were designed, manufactured by SLM process using AlSi10Mg and tested. The mechanical performances of lattice structures with equal relative density, equal base area and height, and equal length for all unit cells were conducted by Finite Element Analysis (FEA). It was found that effective Youngâs modulus is proportional to relative density, but with different affecting levels. When the lattice structures are designed with the same relative density or the same side lengths, the effective Youngâs modulus of lattice structure with triangular prism exhibits the maximum value for both cases. When the lattice structures are designed with the same base areas for all unit cells, the effective Youngâs modulus of lattice structures with square prism presents the maximum. FEA results also show that the maximum stress of lattice structures with triangular prisms in each comparison is at the lowest level and the stiffness-to-mass ratio remains at the maximum value, showing the overwhelming advantages in terms of mechanical strength. The excellent agreements between numerical results and experimental tests reveal the validity of FEA methods applied. The results in this work provide an explicit guideline to fabricate beam-like lattice structures with the best tensile and bending capabilities
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