Tunable sealed-off CW CO laser at room temperature

Starting from a sealed-off CO laser with a long-life output of 29 W/m in multiline operation, we developed a tunable version of this device. The system described has a discharge length of 97 cm. It was made transition-selective by using a three-mirror configuration. In this way we were able to tune the laser to more than 70 oscillating vibrational-rotational transitions of the CO molecule

Design and development of 3D printed fins integrated into an instrumented surfboard

Surfing is a highly competitive sport, to which additive manufacturing technology can be applied to develop new solutions to improve knowledge. The main focus of this study was to design, prototype and test 3D printed surfboard fins with incorporated sensors interfaced with an instrumented surfboard prototype. Specific aim 1 (customisation of a 3D printer in order to 3D print with carbon fibre composites) was addressed by changing the nozzle, extruder, motherboard, stepper drivers, heat bed surface, and introduction of the dry box to the Creality CR-10S 3D printer. Introduced modifications resulted in successful 3D printing using abrasive and hygroscopic filament materials. Specific aim 2 (3D printing of model samples and instrumented fins) was achieved by using a customised 3D printer to fabricate 101 rectangular samples and six instrumented fins. The surfboard fin was designed in CAD and inspired by Futures T1 Twin HC (Futures Fins). Two sensors were incorporated into the fin. The first was 3D printed in-house out of conductive PLA, and TPU filaments while the second one was a commercially obtained 350 Ω full Wheatstone bridge. Specific aim 3 (design, and manufacturing of moulds and tools used for mechanical analysis and data collection unit) was addressed by the development of the so-called pandemic tool, a Shimadzu EZ-S mechanical analyser adapter, touch probe, fin mould, mould for rectangular samples (produced from high-density poly(ethylene) (HDPE) material), and router templates. The comparison between the so-called pandemic tool and the Shimadzu EZ-S laboratory tool showed an excellent accuracy of around 20 % in a range of 0 to around 5 GPa of calculated flexural modulus. The accuracy above 5 GPa was exponentially lower. Specific aim 4 (mechanical analysis of model samples and fins) was achieved using the pandemic tool during Covid-19 pandemic related lockdowns, and the Shimadzu EZ-S between lockdowns. Mechanical analysis of rectangular samples concluded that carbon fibre reinforced Nylon 6 (CF-PA6) with prepreg composite exhibited the highest flexural modulus value (12 ± 1 GPa). The final aim (laboratory and field-testing of instrumented fins) was addressed by laboratory testing of an instrumented fin using a universal mechanical analyser. The results of a tested prototype of an instrumented fin indicated that under tension the commercial Wheatstone bridge exhibited a linear response to applied stroke in a range of up to 7.7 ± 0.1 % of a fin flex. Field-testing was achieved in two trials. The first field test involved driving with a car that had the instrumented surfboard and fins mounted onto it. The second field test involved paddling and walking the instrumented surfboard and fins in a waveless part of the ocean (Gunnamatta Bay, NSW, Australia). The preliminary data results indicate the excellent GPS accuracy of the telemetry unit. Data from sensors installed in the surfboard and fins were saved on the µSD card, while it was simultaneously transferred in real-time between the surfboard’s electronics and the transceiver connected to the laptop with a 13 Hz sampling rate. The main outcome of this project was the development of a working prototype of a surfboard with inbuilt electronics and a set of instrumented fins

Targeting PRMT5 protein-protein interactions with peptidic modulators

Protein arginine methyltransferase 5 (PRMT5) is an important enzyme, methylating arginine residues of its substrates. PRMT5 is involved in a very large number of various cellular process, and has strong ties to a plethora of health disorders. PRMT5 mediates a number of protein-protein interactions (PPIs) with diverse adaptor proteins, such as the obligate binding partner MEP50, and adaptor proteins RioK1, pICln and COPR5. Modulation of PRMT5 PPIs appears as an attractive alternative to the inhibition of the active methylation site, giving an opportunity for significantly more precise targeting of the PRMT5 functionality in cells. This thesis describes pathways for development of peptidomimetics intended for the inhibition of various PPIs formed by PRMT5 or its adaptor protein MEP50. PPI between PRMT5 and MEP50 was investigated using available structural data to design inhibitory peptides. The compounds were synthesised and evaluated using biophysical and enzymatic assays. None of the synthesised compounds showed any activity in the employed assays. In the second part, the thesis describes the analysis of a potential PPI between SUZ12 and MEP50. A number of SUZ12 fragments spanning different protein regions were synthesised and tested for the direct interaction with the PRMT5-MEP50 complex. The analysis indicated that the short SUZ12 sequence CPWCTL is responsible for the interaction with the methyltransferase complex. Further analysis with the binding sequence and control proteins showed very strong non-specific interactions. In light of the obtained results any further peptidomimetic development based on the SUZ12 sequence was not pursued. The final chapters of the thesis focus on the PPIs between PRMT5 and adaptor proteins RioK1, pICln and COPR5. A consensus sequence GQF[D/E]DA[D/E], identified in the terminal regions of the adaptor proteins, was determined to be responsible for mediating the interactions with PRMT5. Biophysical assays and X-ray crystallography allowed to characterise the binding interface and revealed that the consensus sequence binds to the non-catalytic TIM barrel domain of PRMT5. The biophysical data were then used for the design of highly stable macrocyclic PRMT5 adaptor protein interaction inhibitors. Optimisation of the molecular structure resulted in a potent cyclic PRMT5 binder (KD = 89 nM). The developed molecule could inhibit the PPI between PRMT5 and full length pICln when tested in vitro (IC50 = 654 nM). Examination of the compound activity in cellular lysates revealed a surprising selectivity towards the inhibition of the PRMT5 interactions with RioK1 over the interactions with pICln. The developed compound did not supress the enzymatic activity of the methyltransferase and did not inhibit the interaction with MEP50

Controle de qualidade e a produção de sementes de alta qualidade.

Edição dos Anais do XVIII Congresso Brasileiro de Sementes, Florianópolis, set. 2013

Relationship between seed technology research and federal plant breeding programs.

This paper deals with the contributions seed technology can provide for soybean breeding programs for seed quality. Efforts can be placed on seed assurance (DIACOM) to assist the production system, from genetic up to certified seed in releasing a product of high quality. Another approach is the development of screening methods, basead on seed technology tests (vigor tests), for selecting genotypes according to different traits relating to seed quality. An understanding of seed quality mechanisms, such as seed-coat properties, pod-wall permeability, seed and pod resistance to fungi infection, seed shriveling and cell wall permeability, will help to define the screening procedures for this characterisitic. It has been one of the most important contributions that seed technology can provide for the improvement of crops grown in tropical enviroments