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Objectives The aim of this investigation was the detailed analysis of the human pulp proteome using the new picosecond infrared laser (PIRL)-based sampling technique, which is based on a completely different mechanism compared to mechanical sampling. Proteome analysis of healthy pulp can provide data to define changes in the proteome associated with dental disease. Material and methods Immediately after extraction of the entire, undamaged tooth, 15 wisdom teeth were deep frozen in liquid nitrogen and preserved at −80°C. Teeth were crushed, and the excised frozen pulps were conditioned for further analysis. The pulps were sampled using PIRL, and the aspirates digested with trypsin and analyzed with mass spectrometry. Pulp proteins were categorized according to their gene ontology terminus. Proteins identified exclusively in this study were searched in the Human Protein Atlas (HPA) for gaining information about the main known localization and function. Results A total of 1348 proteins were identified in this study. The comparison with prior studies showed a match of 72%. Twenty-eight percent of the proteins were identified exclusively in this study. Considering HPA, almost half of these proteins were assigned to tissues that could be pulp specific. Conclusion PIRL is releasing proteins from the dental pulp which are not dissolved by conventional sampling techniques. Clinical Relevance The presented data extend current knowledge on dental pulp proteomics in healthy teeth and can serve as a reference for studies on pulp proteomics in dental disease.

Across phyla, the ribosomes—the central molecular machines for translation of genetic information—exhibit an overall preserved architecture and a conserved functional core. The natural heterogeneity of the ribosome periodically phases a debate on their functional specialization and the tissue-specific variations of the ribosomal protein (RP) pool. Using sensitive differential proteomics, we performed a thorough quantitative inventory of the protein composition of ribosomes from 3 different mouse brain tissues, i.e., hippocampus, cortex, and cerebellum, across various ages, i.e., juvenile, adult, and middle-aged mouse groups. In all 3 brain tissues, in both monosomal and polysomal ribosome fractions, we detected an invariant set of 72 of 79 core RPs, RACK1 and 2 of the 8 RP paralogs, the stoichiometry of which remained constant across different ages. The amount of a few RPs punctually varied in either one tissue or one age group, but these fluctuations were within the tight bounds of the measurement noise. Further comparison with the ribosomes from a high-metabolic-rate organ, e.g., the liver, revealed protein composition identical to that of the ribosomes from the 3 brain tissues. Together, our data show an invariant protein composition of ribosomes from 4 tissues across different ages of mice and support the idea that functional heterogeneity may arise from factors other than simply ribosomal protein stoichiometry.

Interest in additive manufacturing (AM) has grown exponentially in recent decades and is now being used in many different industries, such as the aerospace, automotive, and biomedical device industries. Unfortunately, the high cost of feedstock powder material, the need for high energy lasers, and a low rate of production have limited the use of this powerful technique on a large scale. Among all the parameters that are crucial in the quality of the parts, the relationship between starting feedstock powder and the quality of the part is not well explored. The common feedstock used in AM, gas atomized powder, requires a high amount of energy and inert gas to be produced. Therefore, gas atomized powder production is costly and not environmentally desirable. AM is believed to produce lower waste compared to the conventional manufacturing process due to minimal required post-processing; however, unless more sustainable starting materials and continuous powder reuse are implemented, the process is very wasteful. The primary focus of this dissertation is on understanding the role of the starting powder on the AM process sustainability in addition to the properties of additively manufactured parts. Powder size and morphology strongly influence powder flow and powder packing density, both of which are critical to successful AM processing. Therefore, the relationship between powder morphological features and flowability was explored and concluded that flowability of powders are heavily influenced by the particles size and shape. In order to reduce the amount of waste produced in laser directed energy deposition (L-DED) process, gas atomized powder was reused, and the reused powders and manufactured parts were characterized. The results indicate that although particles undergo severe changes as they are being reused in AM, the mechanical properties of the manufactured parts show minimal changes. The production of powder from waste material for AM was explored. High energy milling and cryomilling were employed to recycle waste materials to be used as a starting material in AM. The results show that the size and morphology of the produced powder are significantly influenced by the production method, which was modified by tailoring the processing parameters. In addition, the feasibility of depositing aluminum matrix composites has been investigated as a way to improve the mechanical properties of parts manufactured with milled powder. The composite single tracks deposited in L-DED showed comparable morphologies to the single tracks deposited with gas atomized powder. Understanding the effects of using milled powder prepared as composite or recycled powder on the mechanical and microstructural properties of AM parts will be investigated in future work.