Publications by authors named "R G Firth"

The difficulty of quantum chemically computing vibrational, rotational, and rovibrational reference data via quartic force fields (QFFs) for molecules containing aluminum appears to be alleviated herein using a hybrid approach based upon CCSD(T)-F12b/cc-pCVTZ further corrected for conventional CCSD(T) scalar relativity within the harmonic terms and simple CCSD(T)-F12b/cc-pVTZ for the cubic and quartic terms: the F12-TcCR+TZ QFF. Aluminum containing molecules are theorized to participate in significant chemical processes in both the Earth's upper atmosphere as well as within circumstellar and interstellar media. However, experimental data for the identification of these molecules are limited, showcasing the potential for quantum chemistry to contribute significant amounts of spectral reference data.

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The lack of observational data for the AlO molecule in the mesosphere/lower thermosphere may be due to ablated aluminum reacting quickly to form other species. Previously proposed reaction pathways show that aluminum could be ablated in the atmosphere from meteoritic activity, but there currently exist very limited spectroscopic data on the intermediates in these reactions, limiting the possible detection of said molecules. As such, rovibrational spectroscopic data are computed herein using quartic force field methodology at four different levels of theory for the neutral intermediates AlCO3, OAlO2, and HOAlO2.

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The negative ion photoelectron spectra of 1,2-dicyanobenzene (-DCNB), 1,3-dicyanobenzene (-DCNB), and 1,4-dicyanobenzene (-DCNB) radical anions (DCNB·), acquired through the computation of Frack-Condon (FC) factors, are presented. The FC calculations utilize harmonic frequencies and normal mode vectors derived from density functional theory at the B3LYP/aug-cc-pVQZ basis set. All the totally symmetric vibrational modes are treated with Duschinsky rotations to yield neutral DCNBs in their singlet (S) and lowest triplet (T) states, following an electron removal from the doublet anionic ground state.

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Following the report of a non-travel-associated cluster of monkeypox cases by the United Kingdom in May 2022, 41 countries across the WHO European Region have reported 21,098 cases and two deaths by 23 August 2022. Nowcasting suggests a plateauing in case notifications. Most cases (97%) are MSM, with atypical rash-illness presentation.

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Article Synopsis
  • Cerebral palsy (CP), specifically spastic quadriplegia, can be linked to genetic factors, with mutations in the ADD3 gene found to play a role in some cases.
  • A 16-year-old male with spastic diplegia underwent extensive testing, including whole exome sequencing (WES), which identified a biallelic variant in the ADD3 gene associated with inherited cerebral palsy.
  • Researchers developed a Drosophila model to study the effects of ADD3 mutations, revealing that alterations in this gene lead to reduced lifespan and impaired movement, providing insights for potential treatments for ADD3-related cerebral palsy.
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