In situ formation of low molecular weight organogelators for slick solidification

We have investigated the in situ formation of Low Molecular Weight Organogelator (LMWO) molecules in oil-on-water slicks through dual reactive precursor injection. This method alleviates the need for any carrier solvent or prior heating, therefore reducing the environmental impact of LMWOs, giving instantaneous gelation, even at low temperatures (−5 °C). We show minimal leaching from our gels into the water layer

Tracing acid mine drainage and estuarine Zn attenuation using Cd and Zn isotopes

It has been estimated that the acid mine drainage (AMD) impacted Odiel river basin in southern Spain supplies 0.37% and 15% of the global riverine fluxes of Cd and Zn to the oceans, respectively (Sarmiento et al., 2009). However, the behaviour of Cd and Zn in the Ria of Huelva estuary, which connects the Odiel and Tinto watersheds with the Gulf of Cadiz, has yet to be fully investigated. Furthermore, very few studies have investigated Cd and Zn isotope behaviour in estuaries worldwide. This study presents Cd and Zn concentrations and isotopic compositions for the Ria of Huelva estuary and surrounding watersheds, sampled in 2017 and 2019. Sulfide-rich rock samples extracted from three mines yield Cd and Zn isotope compositions that range from –0.14‰ to +0.07‰ (n = 4) for δ114Cd and –0.01‰ to +0.29‰ (n = 4) for δ66Zn. However, a uniform riverine signal of about +0.02‰ for Cd and +0.17‰ for Zn indicates that tracing of individual mining regions using Cd and Zn isotopes is challenging. Limited variability was observed in dissolved δ114Cd values throughout the watershed, including AMD, the estuary, and the Gulf of Cadiz, with a mean value of ±0.00 ± 0.13‰ (n = 25, 2 SD; excludes one AMD outlier, at +0.48‰), including both 2017 and 2019 data. By contrast, δ66Zn values ranged from –0.12‰ to +0.35‰ (n = 28) for the same geographical and temporal scope. In May 2017, a large spill from an abandoned mine, La Zarza, resulted in a drastic increase in the concentrations of trace metals reaching the estuary compared to 2019, but no impact of this mine spill on Cd or Zn isotope compositions is observed. In 2019, an increase in δ66Zn values in the estuary coincided with high pH values (up to pH = 8.8) and chloride concentrations (2.73%), which may reflect an alkaline anthropogenic input from the active neighbouring industrial complex. Overall, Cd concentrations and isotope compositions in the estuary are largely consistent with conservative mixing behaviour. By contrast, Zn behaviour is non-conservative, with removal of 49 to 97% of dissolved riverine Zn in the estuary during the period 2017 to 2019, associated with a relatively small isotopic shift to lighter Zn isotope compositions. Removal of Zn to the particulate phase in the Ria of Huelva estuary therefore largely attenuates high riverine Zn fluxes from AMD, indicating that previously estimated Odiel river basin Zn fluxes were overestimated. Nevertheless, the variable but generally light AMD Cd and Zn isotope compositions, coupled with high dissolved metal concentrations, suggest that Cd and Zn isotopes may be useful tracers of regionally averaged AMD inputs to the Gulf of Cadiz and beyond

A new family of urea-based low molecular-weight organogelators for environmental remediation : the influence of structure

Gelation processes grant access to a wealth of soft materials with tailorable properties, in applications as diverse as environmental remediation, biomedicene and electronics. Several classes of self-assembling gelators have been studied and employ non-covalent bonds to direct assembly, but recently attention has come to focus on how the overall shape of the gelator molecule impacts its gelation. Here we study a new sub-family of low molecular weight organogelators and explore how steric rearrangement influences their gelation. The gels produced are characterised with X-ray diffraction and Small- Angle neutron scattering (SANS) to probe their ex-situ and in-situ gelation mechanisms. The best examples were then tested for environmental remediation applications, gelling petrol and oils in the presence of water and salts

Rhenium-based complexes and in vivo testing: A brief history

The success of metal‐based anticancer therapeutics in the treatment of cancer is best exemplified by cisplatin. Currently used in 32 / 78 cancer regimens, the use for metal‐based therapeutics has a clear role in cancer therapy. Despite this, metal‐based therapeutics are not without drawbacks, with issues such as toxic side effects and the development of resistance mechanisms. This has led to investigations of other metal‐based therapeutics such as auranofin, a gold‐based drug candidate as well as ruthenium‐based candidates, NAMI‐A, NKP‐1339 and TLD‐1433. All are undergoing current clinical trials. Another class of complexes under study are rhenium‐based; such complexes have undergone extensive in vitro testing but only seven have displayed antitumor in vivo activity which is a necessary step before entering clinical trials. This present review will document, chronologically, the rhenium‐based drug candidates that have undergone in vivo testing and the outlook for such complexes

A Global Assessment of Copper, Zinc, and Lead Isotopes in Mineral Dust Sources and Aerosols

The stable isotope compositions of Cu and Zn in major geochemical reservoirs are increasingly studied with the aim to develop these isotope systems as tools to investigate the global biogeochemical cycles of these trace metals. The objectives of the present study were (i) to expand the range of Cu, Zn, and Pb isotope compositions of mineral dust by analyzing samples from major mineral dust sources in Asia and Africa (Chinese Loess Plateau, Chinese deserts, Thar desert, Sahel region) and (ii) to assess the potential impact of human activities on the isotope composition of aerosols by synthesizing published Cu and Zn isotope compositions in aerosols and natural and anthropogenic sources. For the newly analyzed mineral dust areas in Asia and Africa, delta(65)Cu(NIST-976)values range from -0.54 to +0.52 parts per thousand, delta(66)Zn(JMC-Lyon)values from -0.07 to +0.57 parts per thousand, and(206)Pb/Pb-204 values from 18.522 to 19.696. We find a significant geographic control with samples from the Thar Desert having the heaviest isotopic compositions (delta Cu-65(NIST-976)= +0.48 +/- 0.06 parts per thousand, delta Zn-66(JMC-Lyon)= +0.49 +/- 0.11 parts per thousand) and samples from the Sahel and the Badain Jaran desert having the lightest Zn isotope composition (delta Zn-66(JMC-Lyon)= +0.19 +/- 0.15 parts per thousand and +0.07 +/- 0.07 parts per thousand, respectively). We find important variations in the isotope signatures between particle size fractions with heavier isotopic compositions in the smallest and largest particle size fractions and lighter isotopic compositions in the mid particle size fractions. Associations with the mineralogical composition are less clear. Newly analyzed aerosol samples for Beijing and Xi'an show delta(65)Cu(NIST-976)values of +0.29 +/- 0.19 parts per thousand and +0.16 +/- 0.04 parts per thousand, delta(66)Zn(JMC-Lyon)values of -0.36 +/- 0.04 parts per thousand and +0.02 +/- 0.06 parts per thousand, and(206)Pb/Pb-204 values of 18.129 +/- 0.003 and 18.031 +/- 0.003, respectively. Based on a synthesis of published and novel data, we suggest improved ranges and mean values for the isotopic composition of mineral dust from selected locations in Asia and Africa and of anthropogenic sources such as non-exhaust traffic emissions, combustion, electroplating and galvanization. This should serve as a valuable reference for future studies using these isotope systems. This paper demonstrates univocally that human activity introduces a wide range of Zn isotope compositions into the atmospheric environment and, thus, impacts the biogeochemical cycle of Zn