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A novel strain of Paracoccus sp. QD-21, which is capable of simultaneous heterotrophic nitrification and aerobic denitrification, was isolated and investigated for the potential in removal of nitrogen in wastewater treatment. The strain exhibited nitrogen removal rates of 5.55, 3.35, and 2.78 mg/(L·h) for NH₄⁺-N (100 mg/L), NO₂^--N (100 mg/L), and NO₃^--N (100 mg/L), respectively. Notably, QD-21 maintained substantial nitrogen removal efficiency under high concentrations of inorganic nitrogen, highlighting its remarkable tolerance to complex nitrogenous conditions. Optimal nitrogen removal occurred with sodium succinate as carbon source, C/N 7:1, pH 8.41, 140 rpm, 38.41 °C, and inoculum size 4.56% (v/v). Analysis using molecular biology techniques revealed the presence of genes associated with the nitrification process, such as amo and hao, in QD-21. This confirms the nitrification pathway of strain: NH₄⁺-N → NH₂OH → NO₂^--N → NO₃^--N. Additionally, the presence of nirK, norB, and nosZ confirms the denitrification pathway in QD-21: NO₃^--N → NO₂^--N → NO → N₂O → N₂. Meanwhile, the presence of nirBD, nark, glnL, glnA, gltB, and nasA indicates that a portion of nitrogen is assimilated into biomass through the ammonia assimilation pathway, which supports cellular biosynthesis and growth at the expense of metabolic energy. Furthermore, in practical wastewater tests QD-21 achieved removal efficiencies of 75.5% for NH₄⁺-N and 55.8% for COD. Such findings demonstrate the great potential of strain QD-21 in treating nitrogen pollution from diverse sources.

Background: We previously reported the first-in-human evaluation of 3-[¹⁸F]-fluoro-2,2-dimethylpropionic acid ([¹⁸F]FPIA) for imaging aberrant lipid metabolism and cancer detection. The first-generation semi-automated radiosynthesis of [¹⁸F]FPIA required HPLC purification to provide injection solution devoid of precursor (methyl 2,2-dimethyl-3-[(4-methylbenzenesulfonyl)oxy]propanoate), radioactive intermediate (methyl-3-([18F]fluoro)-2,2-dimethylpropanoate), and potential chemical impurities (tosic acid, 3-hydroxy-2,2-dimethylpropanoic acid and unlabelled FPIA). In readiness for global use of [¹⁸F]FPIA, we report a significant improvement to the GMP production through development of a fully-automated solid-phase extraction (SPE) purification method.

Results: We developed a fully-automated SPE purified radiosynthesis on FASTLab™ for GMP readiness that was translated to and validated on the Trasis AIO™ platform for routine clinical use. Purification of the radiotracer by SPE on both systems was achieved (> 98% radiochemical purity), increasing the radiochemical yield compared to the HPLC-based purification method. Non-decay-corrected radiochemical yields (RCY, n.d.c) were 30.3 ± 2.3% (n = 8) and 25.8 ± 6.6% (n = 46) on GE FASTlab™ and Trasis AIO™, respectively. Non-radioactive FPIA and other analytes determined by HPLC were below the limit of detection (< 1.0 µg/mL) from GE FASTlab™ and ≤ 1.2 µg/mL from Trasis AIO™.

Conclusions: The synthesis of [¹⁸F]FPIA was validated on the Trasis AIO™ platform for GMP production and is currently used to produce clinical doses for phase II clinical trials. Readiness for GMP validation was also demonstrated on GE FASTlab™ and can be adopted on other automated platforms.

Low-gradient coastal stream systems support important landscape level ecological functions by connecting uplands and marshes directly to large tidal rivers, estuaries, and coastal waterbodies. In this study, we develop and evaluate innovative monitoring and assessment methods to support biological indicator development for waterbody types and taxa that lack nationally consistent and reliable approaches. Low-gradient tidal and non-tidal coastal stream systems are infrequently included in national and regional monitoring programs and may require different methods than freshwater streams (US EPA National Rivers and Streams Assessment) or large tidal rivers (US EPA National Coastal Condition Assessment). Results from this study demonstrate that stable isotopes of nitrogen (δ¹⁵N) bioindicators from a variety of biotic trophic levels can be used as an efficient and effective rapid monitoring tool for screening level assessment of biotic condition in low-gradient coastal systems. These stable isotope indicators also provide empirical field measurements for ground-truthing national indices which are derived from remotely sensed national landscape data layers. The δ¹⁵N biotic responses were consistently significant across all trophic levels and negatively correlated with landscape level stressor exposure conditions reflected in the national and regional scale indices. Verifying national multiscale indices with site-scale field measured bioindicators (δ¹⁵N) provides coastal managers, states, tribal, regional, and local watershed organizations confidence in using these national indices at local watershed and catchment scales for identifying and prioritizing protection of healthy coastal stream networks and watersheds, as well as targeting critical functional elements of watersheds for restoration efforts.

We develop a refined quantum framework for the induced-fit model of allosteric enzymes incorporating vibrational exciton (Davydov's soliton) dynamics and open-system perturbation theory. Using realistic biochemical parameters, we numerically evaluate the excitation conditions and find that under normal assumptions the quantum excitation energy remains orders of magnitude below the threshold needed to drive a stable soliton. This implies that classical Davydov conditions alone are insufficient for enzyme catalysis on sub-nanosecond timescales. To address this, we identify additional factors - multi-state energy accumulation and strong quantum-coherent processes - that could plausibly enhance the effect. We discuss model limitations (e.g., idealized 1D protein chain, neglect of dissipation) and the validity of our assumptions. By modeling allosteric enzymes as quantum multi-particle systems, we represent substrate-induced structural changes as Hamiltonian deformations and calculate transition probabilities and interaction energies that correlate with enzymatic accuracy or error. While Davydov's soliton offers an appealing formalism, our calculations indicate they are insufficient under naïve parameter choices. Under standard parameters, this mechanism alone is not sufficient and requires auxiliary mechanisms. We present conditions (e.g., multi-state accumulation, enhanced coupling) under which solitonic behaviour might emerge, and propose experiments/simulations to validate these scenarios. This work bridges biophysical mechanisms with quantum mechanics, offering a novel perspective on enzymatic function at the quantum level. Finally, we situate our model within the broader context of macro-quantum effects (quantum coherence, tunneling, superradiance) known in biology, arguing that while Davydov's soliton remains speculative, related quantum phenomena (e.g., proton tunneling) are well-supported in enzymatic systems.