Transformations within container-molecules provide a good alternative between traditional homogeneous and heterogeneous catalysis, as the containers themselves can be regarded as single molecular ...nanomicelles. We report here the designed-synthesis of a water-soluble redox-active supramolecular Pd4L2 cage and its application in the encapsulation of aromatic molecules and polyoxometalates (POMs) catalysts. Compared to the previous known Pd6L4 cage, our results show that replacement of two cis-blocked palladium corners with p-xylene bridges through pyridinium bonds formation between the 2,4,6-tri-4-pyridyl-1,3,5-triazine (TPT) ligands not only provides reversible redox-activities for the new Pd4L2 cage, but also realizes the expansion and subdivision of its internal cavity. An increased number of guests, including polyaromatics and POMs, can be accommodated inside the Pd4L2 cage. Moreover, both conversion and product selectivity (sulfoxide over sulfone) have also been much enhanced in the desulfurization reactions catalyzed by the POMs@Pd4L2 host–guest complexes. We expect that further photochromic or photoredox functions are possible taking advantage of this new generation of organo-palladium cage.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
TROPOspheric Monitoring Instrument (TROPOMI), on‐board the Sentinel‐5 Precurser satellite, is a nadir‐viewing spectrometer measuring reflected sunlight in the ultraviolet, visible, near‐infrared, and ...shortwave infrared. From these spectra several important air quality and climate‐related atmospheric constituents are retrieved, including nitrogen dioxide (NO2) at unprecedented spatial resolution from a satellite platform. We present the first retrievals of TROPOMI NO2 over the Canadian Oil Sands, contrasting them with observations from the Ozone Monitoring Instrument satellite instrument, and demonstrate TROPOMI's ability to resolve individual plumes and highlight its potential for deriving emissions from individual mining facilities. Further, the first TROPOMI NO2 validation is presented, consisting of aircraft and surface in situ NO2 observations, and ground‐based remote‐sensing measurements between March and May 2018. Our comparisons show that the TROPOMI NO2 vertical column densities are highly correlated with the aircraft and surface in situ NO2 observations, and the ground‐based remote‐sensing measurements with a low bias (15–30 %); this bias can be reduced by improved air mass factors.
Plain Language Summary
Nitrogen dioxide (NO2) is a pollutant that is linked to respiratory health issues and has negative environmental impacts such as soil and water acidification. Near the surface the most significant sources of NO2 are fossil fuel combustion and biomass burning. With a recently launched satellite instrument (TROPOspheric Monitoring Instrument TROPOMI), NO2 can be measured with an unprecedented combination of accuracy, spatial coverage, and resolution. This work presents the first TROPOMI NO2 measurements near the Canadian Oil Sands and shows that these measurements have an outstanding ability to detect NO2 on a very high horizontal resolution that is unprecedented for satellite NO2 observations. Further, these satellite measurements are in excellent agreement with aircraft and ground‐based measurements.
Key Points
First evaluation of the TROPOMI NO2 retrieval product
The quality of the TROPOMI NO2 data is excellent and captures variation on a very high spatial resolution
TROPOMI tropospheric NO2 retrievals can be corrected with higher‐resolution input data
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Elton's biotic resistance hypothesis, which posits that diverse communities should be more resistant to biological invasions, has received considerable experimental support. However, it remains ...unclear whether such a negative diversity–invasibility relationship would persist under anthropogenic environmental change. By using the common ragweed (Ambrosia artemisiifolia) as a model invader, our 4‐year grassland experiment demonstrated consistently negative relationships between resident species diversity and community invasibility, irrespective of nitrogen addition, a result further supported by a meta‐analysis. Importantly, our experiment showed that plant diversity consistently resisted invasion simultaneously through increased resident biomass, increased trait dissimilarity among residents, and increased community‐weighted means of resource‐conservative traits that strongly resist invasion, pointing to the importance of both trait complementarity and sampling effects for invasion resistance even under resource enrichment. Our study provides unique evidence that considering species’ functional traits can help further our understanding of biotic resistance to biological invasions in a changing environment.
Whether biodiversity would consistently resist invasion under global change scenarios is poorly understood. Our four‐year grassland experiment showed that plant diversity was a consistent barrier to common ragweed invasion irrespective of nitrogen addition, and that plant diversity resisted invasion simultaneously through increases in the biomass, functional diversity, and dominance of conservative traits, of the resident communities.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The depletion of the Earth's fossil fuel reserves and the rapid increase in the emission of greenhouse gases and other environmental pollutants are driving the development of renewable energy ...technologies. Lignin is one of the three main subcomponents of lignocellulosic biomass in terrestrial ecosystems and makes up nearly 30% of the organic carbon sequestered in the biosphere. As a result of its rich content of aromatic carbon, lignin has the potential to be decomposed to yield valuable chemicals and alternatives to fossil fuels. However, the complex and stable chemical bonds of lignin make the depolymerization of lignin a difficult challenge with regard to its valorization. In this review, we highlight recent advances in the selective decomposition of lignin-based compounds
via
photocatalysis into other value-added chemicals and the treatment of waste water containing lignin. The photocatalytic transformation of lignin under mild conditions is particularly promising.
Photocatalysis as an approach for lignin valorization from energy and environmental viewpoints.
Recent literature claims that China censors information
that has the potential to ignite collective action.
This article extends this finding by arguing that
Chinese censors respond differently to ...political
challenges than they do to performance challenges.
Political challenges call into questioning the
Party's leading role, whereas performance challenges
are directed at the failures of public goods
provisions. A survey experiment of about 60 media
professionals finds that censors are inclined to
block political challenges and to tolerate criticism
of the government's performance. However, when
criticism contains both performance and political
challenges, censorship is far more likely. By
exploring the range of censorship activities, the
results suggest that the Chinese regime's reliance
on popular support constrains its censorship
decisions.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Cytokine release syndrome (CRS) is a major cause of the multi-organ injury and fatal outcome induced by SARS-CoV-2 infection in severe COVID-19 patients. Metabolism can modulate the immune responses ...against infectious diseases, yet our understanding remains limited on how host metabolism correlates with inflammatory responses and affects cytokine release in COVID-19 patients. Here we perform both metabolomics and cytokine/chemokine profiling on serum samples from healthy controls, mild and severe COVID-19 patients, and delineate their global metabolic and immune response landscape. Correlation analyses show tight associations between metabolites and proinflammatory cytokines/chemokines, such as IL-6, M-CSF, IL-1α, IL-1β, and imply a potential regulatory crosstalk between arginine, tryptophan, purine metabolism and hyperinflammation. Importantly, we also demonstrate that targeting metabolism markedly modulates the proinflammatory cytokines release by peripheral blood mononuclear cells isolated from SARS-CoV-2-infected rhesus macaques ex vivo, hinting that exploiting metabolic alterations may be a potential strategy for treating fatal CRS in COVID-19.
Peptide-protein interactions are involved in various fundamental cellular functions and their identification is crucial for designing efficacious peptide therapeutics. Recently, a number of ...computational methods have been developed to predict peptide-protein interactions. However, most of the existing prediction approaches heavily depend on high-resolution structure data. Here, we present a deep learning framework for multi-level peptide-protein interaction prediction, called CAMP, including binary peptide-protein interaction prediction and corresponding peptide binding residue identification. Comprehensive evaluation demonstrated that CAMP can successfully capture the binary interactions between peptides and proteins and identify the binding residues along the peptides involved in the interactions. In addition, CAMP outperformed other state-of-the-art methods on binary peptide-protein interaction prediction. CAMP can serve as a useful tool in peptide-protein interaction prediction and identification of important binding residues in the peptides, which can thus facilitate the peptide drug discovery process.
N6-methyldeoxyadenine (6mA), a major type of DNA methylation in bacteria, represents a part of restriction-modification systems to discriminate host genome from invader DNA
. With the recent advent ...of more sensitive detection techniques, 6mA has also been detected in some eukaryotes
. However, the physiological function of this epigenetic mark in eukaryotes remains elusive. Heritable changes in DNA 5mC methylation have been associated with transgenerational inheritance of responses to a high-fat diet
, thus raising the exciting possibility that 6mA may also be transmitted across generations and serve as a carrier of inheritable information. Using Caenorhabditis elegans as a model, here we report that histone H3K4me3 and DNA 6mA modifications are required for the transmission of mitochondrial stress adaptations to progeny. Intriguingly, the global DNA 6mA level is significantly elevated following mitochondrial perturbation. N6-methyldeoxyadenine marks mitochondrial stress response genes and promotes their transcription to alleviate mitochondrial stress in progeny. These findings suggest that 6mA is a precisely regulated epigenetic mark that modulates stress response and signals transgenerational inheritance in C. elegans.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Recent advances in sensing technologies for detection of phenolic compounds.•Optical detection of phenolic compounds.•Oxidation mechanism of phenolic compounds.•Immobilization methods for ...biosensors.•Application of sensors for pharmaceutical and biomedical analysis.
Phenolic compounds are bioactive natural products of considerable interest in pharmaceuticals and biomedicines. Due to their bioactive functions, phenolic compounds have received increasing attention in recent years. Therefore, it is necessary to develop new and advanced analytical methods for determination of phenolic compounds in relation to pharmaceutical and biomedical applications. However, in majority, their detection has been largely conducted by sensitive yet bulky and expensive laboratory instruments, such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Compared with those laboratory scale instruments, the advanced sensing technologies are extremely attractive due to the advantages of their low cost, time saving, user-friendly, simplified sample pre-treatment, high sensitivity, and excellent selectivity. The aim of this review is to provide critical information on the advanced sensing technologies for detecting phenolic compounds, with emphasis on optical sensors, electrochemical sensors and biosensors. Besides, the present status, critical issues and future trends of the related sensing technologies are outlined.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Metformin, a widely used first-line drug for treatment of type 2 diabetes (T2D), has been shown to extend lifespan and delay the onset of age-related diseases. However, its primary locus of action ...remains unclear. Using a pure in vitro reconstitution system, we demonstrate that metformin acts through the v-ATPase-Ragulator lysosomal pathway to coordinate mTORC1 and AMPK, two hubs governing metabolic programs. We further show in
that both v-ATPase-mediated TORC1 inhibition and v-ATPase-AXIN/LKB1-mediated AMPK activation contribute to the lifespan extension effect of metformin. Elucidating the molecular mechanism of metformin regulated healthspan extension will boost its therapeutic application in the treatment of human aging and age-related diseases.
PDF
