Layered double hydroxides (LDHs), especially (doped) with transition metals, as well as nanohybrid and 2D materials derived from these structures, are interesting materials due to their catalytic and electrochemical properties. Their reactivity is determined by the atomic level distribution of the transition metal in the LDH cation layer, which is essential to control the design of LDHs with optimized properties. However, low crystallinity, absence of long range order, and/or isoelectronic ions often prevent atomic level structural characterization. A series of poorly crystalline Mg2-xNixAl-NO3 LDH materials were investigated by ultrafast 27Al MAS NMR spectroscopy to determine the distribution of Ni2+ in these as well as possible superstructures and their miscibility gaps. Four Ni2Al-LDH samples with interlayer distances ranging from 7.6 to 17.5 Å were prepared to assess the contribution of inter- and intralayer magnetic interactions. The effects of the Ni2+ content and the atomic level distribution of Ni2+ were probed by ultrafast 27Al MAS NMR spectroscopy: the Al distribution can be modeled using a binomial distribution and neither a superstructure was identified for the MgNiAl-LDH sample nor a miscibility gap. The 27Al isotropic shift, δiso(27Al), is a very sensitive probe for a number of neighboring Ni2+ in the first metal ion sphere, but to a smaller degree it is also affected by the intercalated anion (interlayer distance). These results were used for detailed characterization of an exfoliated (2D)-restacked Mg1.83Ni0.17Al-LDH nanohybrid material and a Mg1.83Ni0.17Al-LDH-alginate nanohybrid material, in which 27Al MAS NMR showed how the structure and partial dissolution of the LDHs were retained. In contrast, both powder X-ray diffraction and vibrational spectroscopies (IR and Raman) reflected only the overall change in sample composition.

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Background Anopheles stephensi is an emerging exotic invasive urban vector of malaria in East Africa. The World Health Organization recently announced an initiative to take concerted actions to limit this vector's expansion by strengthening surveillance and control in invaded and potentially receptive territories in Africa. This study sought to determine the geographic distribution of An. stephensi in southern Ethiopia. Methods A targeted entomological survey, both larvae and adult, was conducted in Hawassa city, Southern Ethiopia between November 2022 and February 2023. Anopheles Larvae were reared to adults for species identification. CDC light traps and BG Pro traps were used overnight both indoor and outdoor at selected houses to collect adult mosquitoes in the study area. Prokopack Aspirator was employed to sample indoor resting mosquitoes in the morning. Adults of An. stephensi was identified using morphological keys, and then confirmed by PCR. Results Larvae of An. stephensi were found in 28 (16.6%) of the 169 potential mosquito breeding sites surveyed. Out of 548 adult female Anopheles mosquitoes reared from larvae, 234 (42.7%) were identified to be An. stephensi morphologically. A total of 449 female anophelines were caught, of which 53 (12.0%) were An. stephensi. Other anopheline species collected in the study area included An. gambiae (s.l.), An. pharoensis, An. coustani, and An. demeilloni. Conclusion The study, for the first time, confirmed the presence of An. stephensi in southern Ethiopia. The presence of both larval and adult stages of this mosquito attest that this species established a sympatric colonization with native vector species such as An. gambiae (s.l.) in Southern Ethiopia. The findings warrant further investigation on the ecology, behavior, population genetics, and role of An. stephensi in malaria transmission in Ethiopia.