Miguel Toro-González

Automated detection of features in cryogenic electron microscopy (cryoEM) micrographs is often the first step for quantitative downstream analysis. However, existing tools are often highly specialized for globular proteins, require good templates, or are built upon a large set of labeled images for training. For many non-biological cryoEM datasets labeled training data are unavailable, and samples are not optimized for automated analysis. Here we present CryoBlob, an open-source Python package for feature detection in low-SNR cryo-EM images. CryoBlob is implemented in JAX to allow for GPU acceleration and automatic differentiation during image analysis. The software brings together Laplacian-of-Gaussian blob detection alongside ridge, watershed, and Hessian-based methods to capture circular features, elongated structures, and overlapping objects in a single workflow. The package includes runtime parameter checks via Pydantic, handles large datasets with memory-aware batching, and reads/writes MRC and other common electron microscopy file types directly. In practice, this makes it useful both for quick sample screening and for more detailed quantitative or automated analysis pipelines.

Tungsten-188 is in widespread use in the 188W(t1/2 69 d)/188Re(t1/2 16.9 h) biomedical generator. Oak Ridge National Laboratory (ORNL) has been providing this product to the world since 1999. At ORNL, W-188 is produced via irradiation in ORNL’s High Flux Isotope Reactor (HFIR). Enriched 186W targets in the form of sintered metallic pellets or rings achieve a compact loading in the irradiation vessel, providing a high yield per unit target. The enrichment of the target is >90% 186W and this isotope undergoes double neutron capture to produce the desired 188W product.While 188W is produced by neutron bombardment, 191Os(t1/2 15.4 d) is simultaneously produced as a byproduct requiring separation from 188W by post irradiation treatment. In the current processing pathway, the irradiated W metal pellets or rings are first converted into an oxide form of WO3 by heating the irradiated W metal target at 750oC in a quartz reaction vessel inside a vertical furnace under a constant flow of air. During heating, W metal reacts with oxygen in the air to produce WO3, which is soluble in 6 M NaOH for later purification process. This oxidation process also converts 188Os (the decay daughter of 188W) and 191Os (the irradiation produced byproduct)more » into OsO4, a highly volatile and toxic gas. The gaseous effluents driven from the quartz reaction vessel are passed through a scrubbing array to remove OsO4 before the air is discharged from the process.This heterogeneous oxidation method simultaneously achieves two goals: 1). converting metal target to a soluble oxide form and 2). separating volatile OsO4 away from the solid WO3 product, although harmful 191OsO4 is unfavorable but being taken care of by the down road scrubbing array. In the past twenty years the existing OsO4 scrubbing array served well in preventing OsO4 from being released into the environment, until July of 2020 when a minor amount of 191Os was found to have been released into the environment which resulted in a standby of building 4501 from July 2020 to February 2021.Since October 20 of 2020 a team of researchers from groups of RSTD and NEFD were organized to work for the following tasks:•Fully understand the root causes of the July incident of 191Os release and create a redesigned 191Os scrubbing array to eliminate the possibility of Os-191 release in future W-188 processes•In Phase-1 tests, select a correct air (O2) flow rate in W-188 process, that provides sufficient oxygen for the oxidation of tungsten metal, while still allowing sufficient resonance time for 191Os removal by the scrubbers.•In Phase-2 tests, confirm the efficiency of the redesigned scrubbing array to absorb excessive amount of non-rad OsO4 (generated from Os metal powder) at the selected air flow.•In Phase-3 tests, simulate the hot cell W-188 process by heating pressed non-rad W-Os pellets in a quartz vessel of new design and the new array under operation parameters selected in Phase-1 and -2.•Complete a new operation procedure for W-188 process in hot cell and a TM report as a summary of the Os Mitigation Project.This TM report summarizes the investigation on root causes from technical aspects in July 191Os release and the correspondent improvement towards the redesigned 191Os scrubbing system. The report presents the efforts made on selection of optimal operational parameter with the new scrubbing array and the quartz vessel of new design, based on experiment data obtained in Phase-1, -2 and -3 tests. Further renovations for W-188 process and additional improvement of W target treatment will also be discussed. « less

The development of targeted alpha therapy (TAT) as a viable cancer treatment requires innovative solutions to challenges associated with radionuclide retention to enhance local tumor cytotoxicity and to minimize off-target effects. Nanoparticles (NPs) with high encapsulation and high retention of radionuclides have shown potential in overcoming these issues. This article shows the influence of pH on the structure of lanthanum vanadate (LaVO₄) NPs and its impact on the radiochemical yield of ²²³Ra and subsequent retention of its decay daughters, ²¹¹Pb and ²¹¹Bi. An acidic pH (4.9) results in a high fraction of La(²²³Ra)VO₄ NPs with tetragonal structure (44.6–66.1%) and a ²²³Ra radiochemical yield 80% of La(²²³Ra)VO₄ NPs with monoclinic structure and increases the ²²³Ra radiochemical yield >85%. The leakage of decay daughters from La(²²³Ra)VO₄ NPs (pH 11) was 223Ra)VO₄ NPs with carboxylate and phosphate compounds resulted in a threefold decrease in hydrodynamic diameter and a ²²³Ra radiochemical yield between 74.7% and 99.6%. These results show the importance of tailoring the synthesis parameters and surface chemistry of LaVO₄ NPs to obtain high encapsulation and retention of radionuclides.

This letter reports the development of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) as delivery systems that could potentially encapsulate and improve the administration of radiotherapeutic anticancer agents. Different metal ions (Ba, Gd, and Ce) were used as surrogates of α-emitting radionuclides (²²³Ra, ²²⁵Ac, and ²²⁷Th), and their encapsulation within the PLGA NPs (D_h < 300 nm) was evaluated. The initial concentration of metal ions, the metal salt (nitrate vs chloride), and the presence of chelators influenced the concentration of surrogate ions within the PLGA NPs. This letter shows the potential of PLGA NPs to encapsulate radionuclides, particularly α-emitters, for their application in nuclear medicine.

Unwanted targeting of healthy organs caused by the relocation of radionuclides from the target site has been one of the limiting factors in the widespread application of targeted alpha therapy in patient regimens. GdVO₄ nanoparticles (NPs) were developed as platforms to encapsulate α-emitting radionuclides ²²³Ra, ²²⁵Ac, and ²²⁷Th, and retain their decay daughters at the target site. Polycrystalline GdVO₄ NPs with different morphologies and a zircon-type tetragonal crystal structure were obtained by precipitation of GdCl₃ and Na₃VO₄ in aqueous media at room temperature. The ability of GdVO₄ crystals to host multivalent ions was initially assessed using La, Cs, Bi, Ba, and Pb as surrogates of the radionuclides under investigation. A decrease in Ba encapsulation was obtained after increasing the concentration of surrogate ions, whereas the encapsulation of La cations in GdVO₄ NPs was quantitative (∼100%). Retention of radionuclides was assessed in vitro by dialyzing the radioactive GdVO₄ NPs against deionized water. While ²²⁷Th was quantitatively encapsulated (100%), a partial encapsulation of ²²³Ra (∼75%) and ²²⁵Ac (>60%) was observed in GdVO₄ NPs. The maximum leakage of ²²¹Fr (1st decay daughter of ²²⁵Ac) was 55.4 ± 3.6%, whereas for ²²³Ra (1st decay daughter of ²²⁷Th) the maximum leakage was 73.0 ± 4.0%. These results show the potential of GdVO₄ NPs as platforms of α-emitting radionuclides for their application in targeted alpha therapy.

La(²²⁷Th)PO₄core +2 shells nanoparticles retained >99.75% of activity from²²⁷Th and decay daughters (²²³Ra,²¹¹Pb) for targeted alpha therapy.

How to effectively remove toxic dyes from the industrial wastewater using a green low-cost lignocellulose-based adsorbent, such as lignin, has become a topic of great interest but remains quite challenging. In this study, cosolvent-enhanced lignocellulosic fractionation (CELF) pretreatment and Mannich reaction were combined to generate an aminated CELF lignin which is subsequently applied for removal of methylene blue and direct blue (DB) 1 dye from aqueous solution. ³¹P NMR was used to track the degree of amination, and an orthogonal design was applied to determine the relationship between the extent of amination and reaction parameters. The physicochemical, morphological, and thermal properties of the aminated CELF lignin were characterized to confirm the successful grafting of diethylenetriamine onto the lignin. The aminated CELF lignin proved to be an effective azo dye-adsorbent, demonstrating considerably enhanced dye decolorization, especially toward DB 1 dye (>90%). It had a maximum adsorption capacity of DB 1 dye of 502.7 mg/g, and the kinetic study suggested the adsorption process conformed to a pseudo-second-order kinetic model. The isotherm results also showed that the modified lignin-based adsorbent exhibited monolayer adsorption. The adsorbent properties were mainly attributed to the incorporated amine functionalities as well as the increased specific surface area of the aminated CELF lignin.