24 research outputs found
Nanooptomechanical Transduction in a Single Crystal with 100% Photoconversion.
Materials that exhibit nanooptomechanical transduction in their single-crystal form have prospective use in light-driven molecular machinery, nanotechnology, and quantum computing. Linkage photoisomerization is typically the source of such transduction in coordination complexes, although the isomers tend to undergo only partial photoconversion. We present a nanooptomechanical transducer, trans-[Ru(SO2)(NH3)4(3-bromopyridine)]tosylate2, whose S-bound η1-SO2 isomer fully converts into an O-bound η1-OSO photoisomer that is metastable while kept at 100 K. Its 100% photoconversion is confirmed structurally via photocrystallography, while single-crystal optical absorption and Raman spectroscopies reveal its metal-to-ligand charge-transfer and temperature-dependent characteristics. This perfect optical switching affords the material good prospects for nanooptomechanical transduction with single-photon control
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019
Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe
Structural Capture of η1-OSO to η2-(OS)O Coordination Isomerism in a New Ruthenium-Based SO2-Linkage Photoisomer That Exhibits Single-Crystal Optical Actuation.
Funder: Royal Commission for the Exhibition of 1851Funder: Science and Technology Facilities CouncilFunder: BASFRecent discoveries of a range of single-crystal optical actuators are feeding a new form of materials chemistry, given their broad range of potential applications, from light-induced molecular motors to light sensors and optical-memory media. A series of ruthenium-based coordination complexes that exhibit sulfur dioxide linkage photoisomerization is of particular interest because they exhibit single-crystal optical actuation via either optical switching or nano-optomechanical transduction processes. We report the discovery of a new complex in this series of chemicals, [Ru(SO2)(NH3)4(3-fluoropyridine)]tosylate2 (1), which forms an η1-OSO photoisomer with 70% photoconversion upon the application of 505 nm light. The uncoordinated oxygen atom in this η1-OSO photoisomer impinges on one of the arene rings in a neighboring tosylate counter ion of 1 just enough that incipient nano-optomechanical transduction is observed. The structure and optical properties of this actuator are characterized via in situ light-induced single-crystal X-ray diffraction (photocrystallography), single-crystal optical absorption spectroscopy and microscopy, as well as single-crystal Raman spectroscopy. These materials-characterization methods were also used to track thermally induced reverse isomerization processes in 1. One of these processes involves an η1-OSO to η2-(OS)O transition, which was found to proceed sufficiently slowly at 110 K that its structural mechanism could be determined via a time sequence of photocrystallography experiments. The resulting data allowed us to structurally capture the transition, which was shown to occur via a form of coordination isomerism. Our newfound knowledge about this structural mechanism will aid the molecular design of new [RuSO2] complexes with functional applications.BASF/Royal Academy of Engineering Research Chair in Data-Driven Molecular Engineering of Functional Materials (part of STFC via the ISIS Neutron and Muon Source); the 1851 Royal Commission of the Great Exhibition (2014 Fellowship in Design); U.S. Department of Energy (DOE) Office of Science, Office of Basic Energy Sciences, and used research resources of the Center for Nanoscale Materials, an Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory, supported by the U.S. DOE, all under contract no. DE-AC02-06CH11357; National Council of Science and Technology of Mexico (CONACyT) and the Cambridge Trust for a PhD Scholarship (217553)
Unravelling the synthesis of a rare-earth cluster-based metal–organic framework with spn topology
Y-CU-45, an analogue of Zr-MOF-808, is synthesized for the first time. Several reaction conditions are tested demonstrating that two fluorinated modulators are required for a reproducible synthesis yielding high quality material. Y-CU-45 shows high crystallinity and surface area, shining light on the potential for rare-earth cluster-based MOFs with open metal sites
Unravelling the synthesis of a rare-earth cluster-based metal–organic framework with spn topology
Y-CU-45, an analogue of Zr-MOF-808, is synthesized for the first time. Several reaction conditions are tested demonstrating that two fluorinated modulators are required for a reproducible synthesis yielding high quality material. Y-CU-45 shows high crystallinity and surface area, shining light on the potential for rare-earth cluster-based MOFs with open metal sites
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η2-SO2 Linkage Photoisomer of an Osmium Coordination Complex.
We report the discovery of an η2-SO2 linkage photoisomer in the osmium pentaammine coordination complex, [Os(NH3)5(SO2)][Os(NH3)5(HSO3)]Cl4 (1). Its dark- and light-induced crystal structures are determined via synchrotron X-ray crystallography, at 100 K, where the photoinduced state is metastable in a single crystal that has been stimulated by 505 nm light for 2.5 h. The SO2 photoisomer in the [Os(NH3)5(SO2)]2+ cation contrasts starkly with the photoinactivity of the HSO3 ligand in its companion [Os(NH3)5(HSO3)]+ cation within the crystallographic asymmetric unit of this single crystal. Panchromatic optical absorption characteristics of this single crystal are revealed in both dark- and light-induced states, using concerted absorption spectroscopy and optical microscopy. Its absorption halves across most of its visible spectrum, upon exposure to 505 nm light. The SO2 ligand seems to be responsible for this photoinduced bleaching effect, judging from a comparison of the dark- and light-induced crystal structures of 1. The SO2 photoisomerism is found to be thermally reversible, and so 1 presents a rare example of an osmium-based solid-state optical switch. Such switching in an osmium complex is significant because bottom-row transition metals stand to offer linkage photoisomerism with the greatest photoconversion levels and thermal stability. The demonstration of η2-SO2 bonding in this complex also represents a fundamental contribution to osmium coordination chemistry
η<sup>2</sup>‑SO<sub>2</sub> Linkage Photoisomer of an Osmium Coordination Complex
We report the discovery
of an η<sup>2</sup>-SO<sub>2</sub> linkage photoisomer in the
osmium pentaammine coordination complex, [OsÂ(NH<sub>3</sub>)<sub>5</sub>(SO<sub>2</sub>)]Â[OsÂ(NH<sub>3</sub>)<sub>5</sub>(HSO<sub>3</sub>)]ÂCl<sub>4</sub> (<b>1</b>). Its dark- and light-induced crystal structures
are determined via synchrotron X-ray crystallography, at 100 K, where
the photoinduced state is metastable in a single crystal that has
been stimulated by 505 nm light for 2.5 h. The SO<sub>2</sub> photoisomer
in the [OsÂ(NH<sub>3</sub>)<sub>5</sub>(SO<sub>2</sub>)]<sup>2+</sup> cation contrasts starkly with the photoinactivity of the HSO<sub>3</sub> ligand in its companion [OsÂ(NH<sub>3</sub>)<sub>5</sub>(HSO<sub>3</sub>)]<sup>+</sup> cation within the crystallographic asymmetric
unit of this single crystal. Panchromatic optical absorption characteristics
of this single crystal are revealed in both dark- and light-induced
states, using concerted absorption spectroscopy and optical microscopy.
Its absorption halves across most of its visible spectrum, upon exposure
to 505 nm light. The SO<sub>2</sub> ligand seems to be responsible
for this photoinduced bleaching effect, judging from a comparison
of the dark- and light-induced crystal structures of <b>1</b>. The SO<sub>2</sub> photoisomerism is found to be thermally reversible,
and so <b>1</b> presents a rare example of an osmium-based solid-state
optical switch. Such switching in an osmium complex is significant
because bottom-row transition metals stand to offer linkage photoisomerism
with the greatest photoconversion levels and thermal stability. The
demonstration of η<sup>2</sup>-SO<sub>2</sub> bonding in this
complex also represents a fundamental contribution to osmium coordination
chemistry