Parahydrogen-induced hyperpolarization of a Zn(II) complex using NMR signal amplification by reversible exchange (SABRE).

Although Zn(II) complexes are critical metallobiomolecules in many biological environments, no parahydrogen-based hyperpolarization technique has been reported for such species. Herein, Zn(II)-tris(2-pyridylmethyl)amine (TPA) was hyperpolarized using NMR signal amplification by reversible exchange (SABRE) as a rapid, low-cost, portable, and repeatable technique for spin hyperpolarization. The hyperpolarization of TPA was not significantly affected by Zn(II) relaxation, whereas the polarization trends with respect to magnetic fields and Zn(II) concentrations differed from those of previous reports.

Parahydrogen-Induced Methylated Amino Acid Hyperpolarization and Regression-Based Hyperpolarization Enhancement Factor Prediction.

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are powerful analytical tools with diverse applications in research and medicine. However, the inherently poor signal-to-noise ratios induce technical limitations, which suppress their widespread use. Hyperpolarization enhances the NMR signals by inducing highly nonequilibrated population distributions among the nuclear spin states.

Temperature-Sensitive Magnetic Resonance Probes: Leveraging Hyperpolarized Pyridine-2-Carbaldehyde and SABRE for Real-Time Temperature Sensing.

In this study, we developed a novel approach for real-time, temperature-sensitive nuclear magnetic resonance (NMR) measurements using signal amplification by reversible exchange (SABRE). We discovered that pyridine-2-carbaldehyde (A) exhibits different behavior depending on temperature, showing high hyperpolarization efficiency. In contrast, its reversible reaction product, the hemiacetal form (A'), is not affected by temperature.

Melittin-Phospholipase A Synergism Is Mediated by Liquid-Liquid Miscibility Phase Transition in Giant Unilamellar Vesicles.

The primary constituents of honeybee venom, melittin and phospholipase A (PLA), display toxin synergism in which the PLA activity is significantly enhanced by the presence of melittin. It has been shown previously that this is accomplished by the disruption in lipid packing, which allows PLA to become processive on the membrane surface. In this work, we show that melittin is capable of driving miscibility phase transition in giant unilamellar vesicles (GUVs) and that it raises the miscibility transition temperature () in a concentration-dependent manner.

DFT-Spectroscopy Integrated Identification Method on Unknown Terrorist Chemical Mixtures by Incorporating Experimental and Theoretical GC-MS, NMR, IR, and DFT-NMR/IR Data.

In the event of a chemical attack, the rapid identification of unknown chemical agents is critical for an effective emergency response and treatment of victims. However, identifying unknown compounds is difficult, particularly when relying on traditional methods such as gas and liquid chromatography-mass spectrometry (GC-MS, LC-MS). In this study, we developed a density functional theory and spectroscopy integrated identification method (D-SIIM) for the possible detection of unknown or unidentified terrorist materials, specifically chemical warfare agents (CWAs).

Effect of substituting donors on the hole mobility of hole transporting materials in perovskite solar cells: a DFT study.

Several hole-transporting materials (HTMs) have been designed by incorporating different types of π-conjugation group such as long chain aliphatic alkenes and condensed aromatic rings of benzene and thiophene and their derivatives on both sides between the planar core and donor of a reference HTM. Various electronic, optical, and dynamic properties have been calculated by using DFT, TDDFT, and Marcus theory. In this study, all the designed HTMs show a lower HOMO energy level and match well with the perovskite absorbers.

Water-Compatible and Recyclable Heterogeneous SABRE Catalyst for NMR Signal Amplification.

A water-compatible and recyclable catalyst for nuclear magnetic resonance (NMR) hyperpolarization via signal amplification by reversible exchange (SABRE) was developed. The [Ir(COD)(IMes)Cl] catalyst was attached to a polymeric resin of bis(2-pyridyl)amine (heterogeneous SABRE catalyst, HET-SABRE catalyst), and it amplified the H NMR signal of pyridine up to (-) 4455-fold (43.2%) at 1.

Real-Time Reaction Monitoring of Azide-Alkyne Cycloadditions Using Benchtop NMR-Based Signal Amplification by Reversible Exchange (SABRE).

Rufinamide, possessing a triazole ring, is a new antiepileptic drug (AED) relatively well-absorbed in the lower dose range (10 mg/kg per day) and is currently being used in antiepileptic medications. Triazole derivatives can interact with various enzymes and receptors in biological systems via diverse non-covalent interactions, thus inducing versatile biological effects. Strain-promoted azide-alkyne cycloaddition (SPAAC) is a significant method for obtaining triazoles, even under physiological conditions, in the absence of a copper catalyst.

Hyperpolarization study on remdesivir with its biological reaction monitoring signal amplification by reversible exchange.

Our experiments indicate hyperpolarized proton signals in the entire structure of remdesivir are obtained due to a long-distance polarization transfer by -hydrogen. SABRE-based biological real-time reaction monitoring, by using a protein enzyme under mild conditions is carried out. It represents the first successful -hydrogen based hyperpolarization application in biological reaction monitoring.

Effective degradation of sulfur mustard simulant using novel sulfur-doped mesoporous zinc oxide under ambient conditions.

Sulfur doped metal oxides were synthesized using a two-step precipitation method. When reacted against neat 2-CEES (2-chloroethyl-ethyl sulfide, a mustard gas simulant) under ambient conditions, sulfur doped mesoporous zinc oxide (MS-Zn) showed higher catalytic activity than the other metal oxides with 92.7% overall conversion in 24 h for a 2.

Decomposition of the Simulant 2-Chloroethyl Ethyl Sulfide Blister Agent under Ambient Conditions Using Metal-Organic Frameworks.

Metal organic frameworks (MOFs) have been suggested as promising materials for application in the degradation of chemical warfare agents, with the majority of studies to date focusing on nerve agents. One of the most prominent MOFs used in the detoxification of nerve agents is UiO-66, which is of interest as a future nerve agent decontaminant. However, blister agents, which constitute one of the most toxic and highly reactive categories of chemical agents, are yet to be examined as gas-phase decontamination targets using MOF structures.

Real-Time Reaction Monitoring with In Operando Flow NMR and FTIR Spectroscopy: Reaction Mechanism of Benzoxazole Synthesis.

In operando observation of reaction intermediates is crucial for unraveling reaction mechanisms. To address the sensitivity limitations of commercial ReactIR, a flow cell was integrated with a Fourier transform infrared (FTIR) spectrometer yielding a "flow FTIR" device coupled with an NMR spectrometer for the elucidation of reaction mechanisms. The former device detects the low-intensity IR peaks of reaction intermediates by adjusting the path length of the FTIR sample cell, whereas the flow NMR allows the quantitative analysis of reaction species, thus offsetting the limitations of IR spectroscopy resulting from different absorption coefficients of the normal modes.

Correction: Analysis of 1-aminoisoquinoline using the signal amplification by reversible exchange hyperpolarization technique.

Correction for 'Analysis of 1-aminoisoquinoline using the signal amplification by reversible exchange hyperpolarization technique' by Hye Jin Jeong et al., Analyst, 2020, 145, 6478-6484. DOI: .

Signal amplification by reversible exchange for COVID-19 antiviral drug candidates.

Several drug candidates have been proposed and tested as the latest clinical treatment for coronavirus pneumonia (COVID-19). Chloroquine, hydroxychloroquine, ritonavir/lopinavir, and favipiravir are under trials for the treatment of this disease. The hyperpolarization technique has the ability to further provide a better understanding of the roles of these drugs at the molecular scale and in different applications in the field of nuclear magnetic resonance/magnetic resonance imaging.

Analysis of 1-aminoisoquinoline using the signal amplification by reversible exchange hyperpolarization technique.

Signal amplification by reversible exchange (SABRE), a parahydrogen-based hyperpolarization technique, is valuable in detecting low concentrations of chemical compounds, which facilitates the understanding of their functions at the molecular level as well as their applicability in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). SABRE of 1-aminoisoquinoline (1-AIQ) is significant because isoquinoline derivatives are the fundamental structures in compounds with notable biological activity and are basic organic building blocks. Through this study, we explain how SABRE is applied to hyperpolarize 1-AIQ for diverse solvent systems such as deuterated and non-deuterated solvents.

Hyperpolarization of Nitrile Compounds Using Signal Amplification by Reversible Exchange.

Signal Amplification by Reversible Exchange (SABRE), a hyperpolarization technique, has been harnessed as a powerful tool to achieve useful hyperpolarized materials by polarization transfer from parahydrogen. In this study, we systemically applied SABRE to a series of nitrile compounds, which have been rarely investigated. By performing SABRE in various magnetic fields and concentrations on nitrile compounds, we unveiled its hyperpolarization properties to maximize the spin polarization and its transfer to the next spins.

Organic Reaction Monitoring of a Glycine Derivative Using Signal Amplification by Reversible Exchange-Hyperpolarized Benchtop Nuclear Magnetic Resonance Spectroscopy.

Currently, signal amplification by reversible exchange (SABRE) using -hydrogen is an attractive method of hyperpolarization for overcoming the sensitivity problems of nuclear magnetic resonance (NMR) spectroscopy. Additionally, SABRE, using the spin order of -hydrogen, can be applied in reaction monitoring processes for organic chemistry reactions where a small amount of reactant exists. The organic reaction monitoring system created by integrating SABRE and benchtop NMR is the ideal combination for monitoring a reaction and identifying the small amounts of materials in the middle of the reaction.

SQUID-based ultralow-field MRI of a hyperpolarized material using signal amplification by reversible exchange.

The signal amplification by reversible exchange (SABRE) technique is a very promising method for increasing magnetic resonance (MR) signals. SABRE can play a particularly large role in studies with a low or ultralow magnetic field because they suffer from a low signal-to-noise ratio. In this work, we conducted real-time superconducting quantum interference device (SQUID)-based nuclear magnetic resonance (NMR)/magnetic resonance imaging (MRI) studies in a microtesla-range magnetic field using the SABRE technique after designing a bubble-separated phantom.

Detecting low concentrations of unsaturated C-C bonds by parahydrogen-induced polarization using an efficient home-built parahydrogen generator.

Parahydrogen is a potentially significant source of hyperpolarization. However, a heat exchanger at an ultralow temperature, which is normally sustained wastefully using liquid nitrogen, is essential for the generation of hyperpolarized parahydrogen. In order to cut down on the use of liquid nitrogen, we employed a cryogenic storage dewar as the key component of our home-built parahydrogen generator, which lasted over 20 days with a single filling.

Spatial genetic structure of Aedes aegypti mosquitoes in mainland Southeast Asia.

Aedes aegypti mosquitoes originated in Africa and are thought to have spread recently to Southeast Asia, where they are the major vector of dengue. Thirteen microsatellite loci were used to determine the genetic population structure of A. aegypti at a hierarchy of spatial scales encompassing 36 sites in Myanmar, Cambodia and Thailand, and two sites in Sri Lanka and Nigeria.

Molecular phylogenetics and biogeography of the Neocellia Series of Anopheles mosquitoes in the Oriental Region.

Molecular studies of population divergence and speciation across the Oriental Region are sparse, despite the region's high biodiversity and extensive Pliocene and Pleistocene environmental change. A molecular phylogenetic study of the Neocellia Series of Anopheles mosquitoes was undertaken to identify patterns of diversification across the Oriental Region and to infer the role of Pleistocene and Pliocene climatic change. A robust phylogeny was constructed using CO2 and ND5 mitochondrial genes and ITS2 and D3 nuclear ribosomal markers.

Mitochondrial pseudogenes in the nuclear genome of Aedes aegypti mosquitoes: implications for past and future population genetic studies.

Background: Mitochondrial DNA (mtDNA) is widely used in population genetic and phylogenetic studies in animals. However, such studies can generate misleading results if the species concerned contain nuclear copies of mtDNA (Numts) as these may amplify in addition to, or even instead of, the authentic target mtDNA. The aim of this study was to determine if Numts are present in Aedes aegypti mosquitoes, to characterise any Numts detected, and to assess the utility of using mtDNA for population genetics studies in this species.