Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
15
result(s) for
"de Feyter, Robert"
Sort by:
Nucleotide mismatches prevent intrinsic self-silencing of hpRNA transgenes to enhance RNAi stability in plants
2022
Hairpin RNA (hpRNA) transgenes are the most successful RNA interference (RNAi) method in plants. Here, we show that hpRNA transgenes are invariably methylated in the inverted-repeat (IR) DNA and the adjacent promoter, causing transcriptional self-silencing. Nucleotide substitutions in the sense sequence, disrupting the IR structure, prevent the intrinsic DNA methylation resulting in more uniform and persistent RNAi. Substituting all cytosine with thymine nucleotides, in a G:U hpRNA design, prevents self-silencing but still allows for the formation of hpRNA due to G:U wobble base-pairing. The G:U design induces effective RNAi in 90–96% of transgenic lines, compared to 57–65% for the traditional hpRNA design. While a traditional hpRNA transgene shows increasing self-silencing from cotyledons to true leaves, its G:U counterpart avoids this and induce RNAi throughout plant growth. Furthermore, siRNAs from G:U and traditional hpRNA show different characteristics and appear to function via different pathways to induce target DNA methylation.
Long hairpin RNA (hpRNA) transgenes are the most widely used RNAi technology in plants, but are potentially subject to self-induced transcriptional silencing. Here, the authors show nucleotide mismatches prevent intrinsic self-silencing of hpRNA transgenes in Arabidopsis and tobacco.
Journal Article
Development of a Brassica napus (Canola) Crop Containing Fish Oil-Like Levels of DHA in the Seed Oil
2020
Plant seeds have long been promoted as a production platform for novel fatty acids such as the ω3 long-chain (≥ C20) polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) commonly found in fish oil. In this article we describe the creation of a canola ( Brassica napus ) variety producing fish oil-like levels of DHA in the seed. This was achieved by the introduction of a microalgal/yeast transgenic pathway of seven consecutive enzymatic steps which converted the native substrate oleic acid to α-linolenic acid and, subsequently, to EPA, docosapentaenoic acid (DPA) and DHA. This paper describes construct design and evaluation, plant transformation, event selection, field testing in a wide range of environments, and oil profile stability of the transgenic seed. The stable, high-performing event NS-B50027-4 produced fish oil-like levels of DHA (9–11%) in open field trials of T3 to T7 generation plants in several locations in Australia and Canada. This study also describes the highest seed DHA levels reported thus far and is one of the first examples of a deregulated genetically modified crop with clear health benefits to the consumer.
Journal Article
Comparison of the Substrate Preferences of ω3 Fatty Acid Desaturases for Long Chain Polyunsaturated Fatty Acids
by
Vibhakaran Pillai, Sapna
,
Petrie, James
,
Zhou, Xue-Rong
in
Animals
,
Conversion
,
Cyanobacteria - enzymology
2019
Omega-3 long chain polyunsaturated fatty acids (ω3 LC-PUFAs) such as eicosapentaenoic acid (EPA; 20:5ω3) and docosahexaenoic acid (DHA; 22:6ω3) are important fatty acids for human health. These ω3 LC-PUFAs are produced from their ω3 precursors by a set of desaturases and elongases involved in the biosynthesis pathway and are also converted from ω6 LC-PUFA by omega-3 desaturases (ω3Ds). Here, we have investigated eight ω3-desaturases obtained from a cyanobacterium, plants, fungi and a lower animal species for their activities and compared their specificities for various C18, C20 and C22 ω6 PUFA substrates by transiently expressing them in Nicotiana benthamiana leaves. Our results showed hitherto unreported activity of many of the ω3Ds on ω6 LC-PUFA substrates leading to their conversion to ω3 LC-PUFAs. This discovery could be important in the engineering of EPA and DHA in heterologous hosts.
Journal Article
Coronary angiography with multi-slice computed tomography
2001
A new generation of subsecond multi-slice computed tomography (MSCT) scanners, which allow complete coronary coverage, are becoming widely available. We investigated the potential value of MSCT angiography in a range of coronary disorders.
We studied 35 patients, including 11 who had undergone percutaneous transluminal coronary angioplasty and four who had had coronary-artery bypass grafts, by both MSCT and conventional coronary angiography. After intravenous injection of a non-ionic contrast medium with high iodine content, the entire heart was scanned within a single breath-hold. The total examination time was no more than 20 min. The retrospective electrocardiographically gated reconstruction source images and three-dimensional reconstructed volumes were analysed by two investigators, unaware of the results of conventional angiography.
In the 31 patients without previous coronary surgery, 173 (73%) of the 237 proximal and middle coronary segments were assessable. In the assessable segments, 17 of 21 significant stenoses (>50% reduction of vessel diameter) were correctly diagnosed. The non-assessable segments included four lesions. Misinterpretations were mainly the result of severe calcification of the vessel wall. Segments with implanted stents were poorly visualised, but stent patency could be assessed in all cases. Of the 17 segments of bypass grafts, 15 were assessable and four of five graft lesions were detected. Two cases of anomalous coronary anatomy could be visualised well.
These preliminary data suggest that MSCT allows non-invasive imaging of coronary-artery stenoses and has potential to develop into a reliable clinical technique.
Journal Article
Navigating the Future: Remote Operations for Inland Shipping
by
Feyter, Jason De
,
Bargsten, Janis
,
Chernyavskiy, Aleksander
in
Artificial intelligence
,
Inland waterway transportation
,
Shipping
2025
The increasing shortage in crew and the push towards automation in inland shipping has brought about significant innovations in smart shipping. This paper explores the critical technological advancements and challenges associated with implementing remote operation systems for inland waterway transport. As global trade expands and environmental sustainability becomes more crucial, the adoption of automated and smart systems in IWT offers a promising solution for enhancing operational efficiency while reducing environmental impact. Our findings outline the technical requirements, such as monitoring, connectivity, and control systems, that are essential for the successful implementation of remote operations within the framework of smart shipping. Additionally, it highlights the importance of safety, redundancy in communication, and the role of artificial intelligence in ensuring situational awareness and operational efficiency. The research findings conclude that while substantial progress has been made, continued advancements in technology and regulatory support are essential to fully realize the potential of smart shipping in inland waterways.
Journal Article
An embedded interfacial network stabilizes inorganic CsPbI3 perovskite thin films
2022
The black perovskite phase of CsPbI
3
is promising for optoelectronic applications; however, it is unstable under ambient conditions, transforming within minutes into an optically inactive yellow phase, a fact that has so far prevented its widespread adoption. Here we use coarse photolithography to embed a PbI
2
-based interfacial microstructure into otherwise-unstable CsPbI
3
perovskite thin films and devices. Films fitted with a tessellating microgrid are rendered resistant to moisture-triggered decay and exhibit enhanced long-term stability of the black phase (beyond 2.5 years in a dry environment), due to increasing the phase transition energy barrier and limiting the spread of potential yellow phase formation to structurally isolated domains of the grid. This stabilizing effect is readily achieved at the device level, where unencapsulated CsPbI
3
perovskite photodetectors display ambient-stable operation. These findings provide insights into the nature of phase destabilization in emerging CsPbI
3
perovskite devices and demonstrate an effective stabilization procedure which is entirely orthogonal to existing approaches.
Lattice anchoring, in its varied forms, has proven effective at regulating the energetics of metastable phases of polymorphic crystals. Here, the authors utilize top-down photolithography to embed a tessellating 3D interfacial network into otherwise-unstable CsPbI
3
perovskite thin films and devices, stabilizing the perovskite phase.
Journal Article
Reproducibility of intravascular ultrasound radiofrequency data analysis: implications for the design of longitudinal studies
by
Regar, Evelyn
,
Rodriguez-Granillo, Gastón A.
,
de Feyter, Pim J.
in
Coronary Disease - diagnostic imaging
,
Coronary Vessels - diagnostic imaging
,
Female
2006
The purpose of this study was to assess in vivo the reproducibility of tissue characterization using spectral analysis of intravascular ultrasound (IVUS) radiofrequency data (IVUS-VH).
Despite the need for reproducibility data to design longitudinal studies, such information remains unexplored.
IVUS-VH (Volcano Corp., Rancho Cordova, USA) was performed in patients referred for elective percutaneous intervention and in whom a non-intervened vessel was judged suitable for a safe IVUS interrogation. The IVUS catheters used were commercially available catheters (20 MHz, Volcano Corp., Rancho Cordova, USA). Following IVUS-VH acquisition, and after the disengagement and re-engagement of the guiding catheter, an additional acquisition was performed using a new IVUS catheter. Fifteen patients with 16 non-significant lesions were assessed by 2 independent observers. The relative inter-catheter differences regarding geometrical measurements were negligible for both observers. The inter-catheter relative difference in plaque cross-sectional area (CSA) was 3.2% for observer 1 and 0.5% for observer 2. The limits of agreement for (observer 1 measurements) lumen, vessel, plaque and plaque burden measurements were 0.82, -1.10 mm(2); 0.80, -0.66 mm(2); 1.08, -0.66 mm(2); and 5.83, -3.89%; respectively. Limits of agreement for calcium, fibrous, fibrolipidic and necrotic core CSA measurements were 0.22, -0.25 mm(2); 1.02, -0.71 mm(2); 0.61, -0.65 mm(2); and 0.43, -0.38 mm(2) respectively. Regarding the inter-observer agreement, the limits of agreement for lumen, vessel, plaque and plaque burden measurements were 2.61, -2.09 mm(2); 2.20-3.03 mm(2); 1.70, -3.04 mm(2); and 9.16, -16.41%; respectively, and for calcium, fibrous, fibrolipidic and necrotic core measurements of 0.08, -0.09 mm(2); 0.89, -1.28 mm(2); 0.74, -1.06 mm(2); and 0.16, -0.20 mm(2); respectively.
The present study demonstrates that the geometrical and compositional output of IVUS-VH is acceptably reproducible.
Journal Article
An embedded interfacial network stabilizes inorganic CsPbI 3 perovskite thin films
2022
The black perovskite phase of CsPbI
is promising for optoelectronic applications; however, it is unstable under ambient conditions, transforming within minutes into an optically inactive yellow phase, a fact that has so far prevented its widespread adoption. Here we use coarse photolithography to embed a PbI
-based interfacial microstructure into otherwise-unstable CsPbI
perovskite thin films and devices. Films fitted with a tessellating microgrid are rendered resistant to moisture-triggered decay and exhibit enhanced long-term stability of the black phase (beyond 2.5 years in a dry environment), due to increasing the phase transition energy barrier and limiting the spread of potential yellow phase formation to structurally isolated domains of the grid. This stabilizing effect is readily achieved at the device level, where unencapsulated CsPbI
perovskite photodetectors display ambient-stable operation. These findings provide insights into the nature of phase destabilization in emerging CsPbI
perovskite devices and demonstrate an effective stabilization procedure which is entirely orthogonal to existing approaches.
Journal Article