Flow optimization study of a batch microfluidics PET tracer synthesizing device.

We present numerical modeling and experimental studies of flow optimization inside a batch microfluidic micro-reactor used for synthesis of human-scale doses of Positron Emission Tomography (PET) tracers. Novel techniques are used for mixing within, and eluting liquid out of, the coin-shaped reaction chamber. Numerical solutions of the general incompressible Navier Stokes equations along with time-dependent elution scalar field equation for the three dimensional coin-shaped geometry were obtained and validated using fluorescence imaging analysis techniques. Utilizing the approach presented in this work, we were able to identify optimized geometrical and operational conditions for the micro-reactor in the absence of radioactive material commonly used in PET related tracer production platforms as well as evaluate the designed and fabricated micro-reactor using numerical and experimental validations

Simulations of slip flow on nanobubble-laden surfaces

On microstructured hydrophobic surfaces, geometrical patterns may lead to the appearance of a superhydrophobic state, where gas bubbles at the surface can have a strong impact on the fluid flow along such surfaces. In particular, they can strongly influence a detected slip at the surface. We present two-phase lattice Boltzmann simulations of a flow over structured surfaces with attached gas bubbles and demonstrate how the detected slip depends on the pattern geometry, the bulk pressure, or the shear rate. Since a large slip leads to reduced friction, our results allow to assist in the optimization of microchannel flows for large throughput.Comment: 22 pages, 12 figure

FEM modeling of energy dissipation in SMRs

The main objective of this work is to develop a reliable numerical model to describe dissipation in Suspended Microchannel Resonators, through determination of the Quality Factor, as a costless and quickly reproducible procedure to determine the effectiveness and performance of these innovative MEMS for bio-sensing. Through comparison of numerical results with theoretical and experimental results available in literature we aimed to contribute to the research and understanding of the physical phenomena occurring in these recently developed devices, putting under question some of the previous results and opening to new possibile interpretations and discussions

Food Extract of Purple Yam (Dioscorea trifida L.f.) from Brazil: Optimization of Extraction Method, Characterization, In Vivo Toxicity, and Antimicrobial Activity

Purple yam (Dioscorea trifida) has high agricultural productivity in the Amazon region but has not been much investigated. Multivariate strategies were employed to optimize the method to obtain a food extract rich in functional compounds. The optimal conditions showed that the combination of 0.2 g of dried purple yam with 15 mL of citric acid (1%) under agitation in a water bath at 36 °C for 4 min yields an extract with a high content of peonidin-3-O-glucoside-5-O-glucoside, peonidin-3-O-feruloylglycosideum-5-O-glycosideum, peonidin-3-Op-coumaroylglycosideum-5-O-glycoside, quinic acid, apigenin 8-C-xyloside-6-C-glycoside (vicenin 3), quinic acid, apigenin 6-C-xyloside-8-C-glycoside (vicenin 1), and isorhamnetin-O-dihexoside. Our extract also presented 56.91 ± 0.76 mg 100 g−1 of total anthocyanins, 417.05 ± 11.37 mg 100 g−1 total carotenoids, and 493.09 ± 6.38 mg GAE 100 g−1 of total phenolic compounds. In a Galleria mellonella, in vivo model consumption safety was for up to 150 g by 70 kg of body weight. In addition, it inhibited the growth of Gram-negative bacteria (Salmonella typhimurium and Escherichia coli). The simple, fast, and ecofriendly extraction conditions, combined with the biological effects of our extract, gives us a great potential for its application in food or packaging technologies.This study was funded by the Coordination for the Improvement of Higher Education Personnel (Funding 001). The Foundation for Science and Technology (FCT, Portugal) provided financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021). The FCT through the institutional scientific employment program contract provided contract for L. Barros. The BPI La Caixa Foundation, within project titled “AquaeVitae—Thermal Water as a Source of Life and Health” — “PROMOVE – The future of the Interior” call 2020, provided contract for T. Silveira.info:eu-repo/semantics/publishedVersio

Nuclear variants of bone morphogenetic proteins

<p>Abstract</p> <p>Background</p> <p>Bone morphogenetic proteins (BMPs) contribute to many different aspects of development including mesoderm formation, heart development, neurogenesis, skeletal development, and axis formation. They have previously been recognized only as secreted growth factors, but the present study detected Bmp2, Bmp4, and Gdf5/CDMP1 in the nuclei of cultured cells using immunocytochemistry and immunoblotting of nuclear extracts.</p> <p>Results</p> <p>In all three proteins, a bipartite nuclear localization signal (NLS) was found to overlap the site at which the proproteins are cleaved to release the mature growth factors from the propeptides. Mutational analyses indicated that the nuclear variants of these three proteins are produced by initiating translation from downstream alternative start codons. The resulting proteins lack N-terminal signal peptides and are therefore translated in the cytoplasm rather than the endoplasmic reticulum, thus avoiding proteolytic processing in the secretory pathway. Instead, the uncleaved proteins (designated nBmp2, nBmp4, and nGdf5) containing the intact NLSs are translocated to the nucleus. Immunostaining of endogenous nBmp2 in cultured cells demonstrated that the amount of nBmp2 as well as its nuclear/cytoplasmic distribution differs between cells that are in M-phase versus other phases of the cell cycle.</p> <p>Conclusions</p> <p>The observation that nBmp2 localization varies throughout the cell cycle, as well as the conservation of a nuclear localization mechanism among three different BMP family members, suggests that these novel nuclear variants of BMP family proteins play an important functional role in the cell.</p

Cooperative Interaction of Transcription Termination Factors with the RNA Polymerase II C-terminal Domain

Phosphorylation of the C-terminal domain of RNA polymerase II controls the co-transcriptional assembly of RNA processing and transcription factors. Recruitment relies on conserved CTDinteracting domains that recognize different CTD phosphoisoforms during the transcription cycle, but the molecular basis for their specificity remains unclear. We show that the CTD-interacting domains of two transcription termination factors, Rtt103 and Pcf11, achieve high affinity and specificity both by specifically recognizing the phosphorylated CTD and by cooperatively binding to neighboring CTD repeats. Single amino acid mutations at the protein-protein interface abolish cooperativity and affect recruitment at the 3′-end processing site in vivo. We suggest that this cooperativity provides a signal-response mechanism to ensure that its action is confined only to proper polyadenylation sites where Serine 2 phosphorylation density is highest