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Enhancing the initial stages of plant growth by using polymeric gels for seed priming presents a significant challenge. This study aimed to investigate a microgel derived from polyetheramine-poly(propylene oxide) (PPO) and a bisepoxide (referred to as micro-PPO) as a promising alternative to optimize the seed germination process. The micro-PPO integrated with an iron micronutrient showed a positive impact on seed germination compared with control (Fe solutions) in which the root length yield improved up to 39%. Therefore, the element map by synchrotron-based X-ray fluorescence shows that the Fe intensities in the seed primers with the micro-PPO-Fe gel are about 3-fold higher than those in the control group, leading to a gradual distribution of Fe species through most internal embryo tissues. The use of micro-PPO for seed priming underscores their potential for industrial applications due to the nontoxicity results in zebrafish assays and environmentally friendly synthesis of the water-dispersible monomers employed.

Recovering rare earth elements (REE) as by-products of existing mineral operations is a low-investment option to increase supply in short terms. REE-minerals were reported for the São João del Rei Pegmatitic Province (southern Minas Gerais State, Brazil) since the late 1940s, but data is scarce and dubious. The largest pegmatites project in the Province – Volta Grande mine – has been mined since 1945, producing concentrates of cassiterite, columbite-subgroup minerals, and microlite, and since 2018 spodumene is also recovered. Here we prepare a stream-specific mineralogical characterisation of the beneficiation plants to identify REE-minerals for potential REE recovery. The results analyse the feasibility of reprocessing some streams to generate a high-apatite product adequate for phosphoric acid production with REE recovery as by-products. The further REE speciation also revealed the preferential distribution of heavy-REE into columbite-subgroup minerals and light-REE into microlite, which may represent promising targets for the production of concentrates with high-purity.

Copolymerization of silicon alkoxides in alcoholic basic medium using trialkyl- or triarylchlorosilanes as terminator was investigated. Tetraethoxysilane (TEOS), phenyltriethoxysilane (PTEOS) and vinyltriethoxysilane (VTEOS) were used as monomers and triphenylchlorosilane (TPCS) and trimethylchlorosilane (TMCS) as terminator. The copolymerization of TEOS with PTEOS and VTEOS produces core-shell silica-silicone nanospherical hybrids containing large amounts of functional groups in the structure of their external layer. The structure is the result of the fast hopolymerization of TEOS in a first stage of the reaction, forming the core, followed by copolymerization of TEOS and the alkyl- or vinyl-trialkoxysilane comonomer in its last stage. The structure was confirmed by Raman and FTIR spectroscopy, wide angle X-ray scattering (WAXS) and thermogravimetry. The control of particle size is effectively made by the termination reaction and particles with average diameter between 20 and 100 nm were obtained. Introduction of other chemical functions on the surface of these nanoparticles can be carried out by common reactions with the functional surface groups. As an example, sulfonation of particles containing phenyl groups on the surface by direct sulfuric acid and chlorosulfonic acid was investigated and the results discussed.

Preservation of ovarian functions in woman with premature ovarian failure remains an issue in reproductive medicine. Hormone replacement therapy for maintaining endocrine functions, and cryopreservation of embryos or oocytes for those who wish pregnancy, are some of the choices. However, ovarian transplantation is a more physiological alternative, although problems related to ovarian ischemia have been reported. Herein, we investigated the viability of autologous transplantation of the ovarian tissue into the rat peritoneum, without vascular reanastomosis. Twenty animals in the study group had both ovaries excised, and each ovary was dissected into two halves. A half of an ovary was autotransplanted to the peritoneal surface, closely located to the left epigastric vessels. This simple procedure does not require surgical vascular reanastomosis while it maintains appropriate follicular growth and therefore should be further considered as an alternative for women undergoing ooforectomy, not only to maintain endocrine functions but also for fertility preservation.

We used the Submillimeter Array to observe the thermal polarized dust emission from the protostellar source NGC 2024 FIR 5. The polarized emission outlines a partial hourglass morphology for the plane-of-sky component of the core magnetic field. Our data are consistent with previous BIMA maps, and the overall magnetic field geometries obtained with both instruments are similar. We resolve the main core into two components, FIR 5A and FIR 5B. A possible explanation for the asymmetrical field lies in depolarization effects due to the lack of internal heating from the FIR 5B source, which may be in a prestellar evolutionary state. The field strength was estimated to be 2.2 mG, in agreement with previous BIMA data. We discuss the influence of a nearby H II region over the field lines at scales of [?]0.01 pc. Although the hot component is probably compressing the molecular gas where the dust core is embedded, it is unlikely that the radiation pressure exceeds the magnetic tension. Finally, a complex outflow morphology is observed in CO (3 - 2) maps. Unlike previous maps, several features associated with dust condensations other than FIR 5 are detected.

Direct numerical simulations (DNS) provide useful information for the understanding and the modeling of turbulence phenomena. In particular, new methodologies recently allowed the achievement of high Reynolds number in DNS of the benchmark plane channel flow. In this scenario, estimating the statistical errors associated with DNS is a difficult but necessary task. Here, we present a methodology to evaluate the statistical errors of the second-moment DNS data. In this methodology, the momentum balance equation is used to calculate the mean velocity profile by considering the Reynolds stress tensor provided by DNS. This error evaluation was applied to different plane channel flow databases available in the literature. We show that using the Reynolds stress statistics obtained from standard DNS can lead to significant discrepancies for turbulence modeling. One interesting consequence of this approach is that we are able to compute the Reynolds shear stress from the converged first order statistic. This information can be used, for instance, to extract a more accurate turbulent viscosity for turbulence modeling purposes. Moreover, the new methodology seems to be a promising path to formulate a convergence criterion for future plane channel DNS. [ABSTRACT FROM AUTHOR]