A Year in Syntropy: Exploring Syntropic Agriculture

Syntropic agriculture is a form of sustainable agriculture that originated in Brazil around 25 years ago. Although it has since spread throughout Brazil and Australia, there has yet to be a comprehensive study of the driving scientific principles behind syntropy. For my thesis, I conducted literature research and interviews with farmers, with the goal of describing the ecological principles on which syntropy is based, including its primary goal to improve soil health. Much of my thesis contrasted syntropic agriculture with conventional agriculture as practiced in the United States today, but I also explored the differences between syntropic agriculture and other forms of sustainable agriculture, as well as the current economic agricultural landscape in the United States. I wrote my thesis in the form of a blog, with weekly posts examining different aspects of syntropy, agricultural systems, and U.S. agricultural economics. By using the blog format, I aimed to make the information accessible for a non-scientific audience, using colloquial language and a casual tone. From my research, I conclude that syntropic agriculture could reasonably replace conventional farming as practiced in the United States today

Cotton Defoliation Guide in Texas.

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Combined homogeneous and heterogeneous hydrogenation to yield catalyst-free solutions of parahydrogen-hyperpolarized [1-13C]succinate

We show that catalyst-free aqueous solutions of hyperpolarized [1-13C]succinate can be produced using parahydrogen-induced polarization (PHIP) and a combination of homogeneous and heterogeneous catalytic hydrogenation reactions. We generate hyperpolarized [1-13C]fumarate via PHIP using para-enriched hydrogen gas with a homogeneous ruthenium catalyst, and subsequently remove the toxic catalyst and reaction side products via a purification procedure. Following this, we perform a second hydrogenation reaction using normal hydrogen gas to convert the fumarate into succinate using a solid Pd/Al2O3 catalyst. This inexpensive polarization protocol has a turnover time of a few minutes, and represents a major advance for in vivo applications of [1-13C]succinate as a hyperpolarized contrast agent

Possible Applications of Dissolution Dynamic Nuclear Polarization in Conjunction with Zero- to Ultralow-Field Nuclear Magnetic Resonance

The combination of a powerful and broadly applicable nuclear hyperpolarization technique with emerging (near-)zero-field modalities offer novel opportunities in a broad range of nuclear magnetic resonance spectroscopy and imaging applications, including biomedical diagnostics, monitoring catalytic reactions within metal reactors and many others. These are discussed along with a roadmap for future developments.Comment: 12 pages, 5 figure

Rapid hyperpolarization and purification of the metabolite fumarate in aqueous solution

Hyperpolarized fumarate is a promising biosensor for carbon-13 magnetic resonance metabolic imaging. Such molecular imaging applications require nuclear hyperpolarization to attain sufficient signal strength. Dissolution dynamic nuclear polarization is the current state-of-the-art methodology for hyperpolarizing fumarate, but this is expensive and relatively slow. Alternatively, this important biomolecule can be hyperpolarized in a cheap and convenient manner using parahydrogen-induced polarization. However, this process requires a chemical reaction, and the resulting solutions are contaminated with the catalyst, unreacted reagents, and reaction side-product molecules, and are hence unsuitable for use in vivo. In this work we show that the hyperpolarized fumarate can be purified from these contaminants by acid precipitation as a pure solid, and later redissolved to a desired concentration in a clean aqueous solvent. Significant advances in the reaction conditions and reactor equipment allow for formation of hyperpolarized fumarate at ¹³C polarization levels of 30–45%

Advances in parahydrogen-enhanced nuclear magnetic resonance

Nuclear magnetic resonance is a powerful spectroscopic tool, which has found applications in fields such as chemistry, the life sciences, medical imaging, and even fundamental physics, but is often limited by the low polarization of nuclear spins in ambient conditions. Hyperpolarization techniques are used to increase the spin polarization, which can lead to large signal enhancements. In the context of magnetic resonance imaging, this can allow for in vivo observation of metabolites at physiological concentrations, which would otherwise not be possible given current sensitivity limits.This thesis describes a number of hyperpolarization methods and their applications to in vivo imaging, with particular emphasis on parahydrogen-induced hyperpolarization. This technique allows for the production hyperpolarized samples via chemical reaction with a specific spin-isomer of hydrogen gas. Theory and experiments for producing hyperpolarized samples are described that advance this methodology towards eventual clinical applicatio

A pulse sequence for singlet to heteronuclear magnetization transfer: S2hM

We have recently demonstrated, in the context of para-hydrogen induced polarization (PHIP), the conversion of hyperpolarized proton singlet order into heteronuclear magnetisation can be efficiently achieved via a new sequence named S2hM (Singlet to heteronuclear Magnetisation). In this paper we give a detailed theoretical description, supported by an experimental illustration, of S2hM. Theory and experiments on thermally polarized samples demonstrate the proposed method is robust to frequency offset mismatches and radiofrequency field inhomogeneities. The simple implementation, optimisation and the high conversion efficiency, under various regimes of magnetic equivalence, makes S2hM an excellent candidate for a widespread use, particularly within the PHIP arena