Electrochemically converting nitrate, a widespread water pollutant, back to valuable ammonia is a green and delocalized route for ammonia synthesis, and can be an appealing and supplementary ...alternative to the Haber-Bosch process. However, as there are other nitrate reduction pathways present, selectively guiding the reaction pathway towards ammonia is currently challenged by the lack of efficient catalysts. Here we report a selective and active nitrate reduction to ammonia on Fe single atom catalyst, with a maximal ammonia Faradaic efficiency of ~ 75% and a yield rate of up to ~ 20,000 μg h
mg
(0.46 mmol h
cm
). Our Fe single atom catalyst can effectively prevent the N-N coupling step required for N
due to the lack of neighboring metal sites, promoting ammonia product selectivity. Density functional theory calculations reveal the reaction mechanisms and the potential limiting steps for nitrate reduction on atomically dispersed Fe sites.
Insertion of transition metal elements into organic polymeric scaffolds enables a nice coupling of the intriguing physical traits of metal complexes such as electronic, optical and magnetic ...properties with the solution processability of carbon-based macromolecules. The propensity of these metal-based polymers towards exhibiting metal-metal interactions can also provide additional means for manipulating the structural order and electronic coupling in the molecules. Among these metallopolymers, rigid-rod transition metal σ-acetylide polymers, or polymetallaynes in short, are of much current interest. These organometallic polymers are important functional materials showing unique characteristics including electrical semiconductivity, photo-/electroluminescence, non-linear optical properties, liquid crystallinity, chemosensing capability and photovoltaic effect. Recently, there has been an impressive progress of functional polymetallaynes consisting of a variety of conjugated organic bridging moieties and transition metals. In this review, we summarize the structure-property-function relationships of polymetallaynes of different transition metals, with a major focus on the effect of transition metals and the structural modification of ligands in activating their multifunctional properties. Different emerging applications can thus be realized, for example, as the converters for both light/electricity signals, sensor protectors against intense laser beam and patternable precursors to magnetic metal alloy nanoparticles for data storage,
etc.
Polymetallaynes of late transition metal elements have aroused considerable research attention. This Review article highlights the structure-property-function relationships of this class of metallopolymers and their emerging applications in electronic, optical and magnetic devices.
Self‐assembly of d8 metal polypyridine systems is a well‐established approach for the creation of 1D organometallic assemblies but there are still challenges for the large‐scale construction of ...nanostructured patterns from these building blocks. We describe herein the use of high‐throughput nanoimprint lithography (NIL) to direct the self‐assembly of the bimetallic complexes 4′‐ferrocenyl‐(2,2′:6′,2′′‐terpyridine)M(OAc)+(OAc)− (M=Pd or Pt; OAc=acetate). Uniform nanorods are fabricated from the molecular self‐organization and evidenced by morphological characterization. More importantly, when top‐down NIL is coupled with the bottom‐up self‐assembly of the organometallic building blocks, regular arrays of nanorods can be accessed and the patterns can be controlled by changing the lithographic stamp, where the mold imposes a confinement effect on the nanorod growth. In addition, patterns consisting of the products formed after pyrolysis are studied. The resulting arrays of ferromagnetic FeM alloy nanorods suggest promising potential for the scalable production of ordered magnetic arrays and fabrication of magnetic bit‐patterned media.
Back in print: Top‐down lithography is coupled with bottom‐up self‐assembly. The molecular self‐assembly of bimetallic complexes to give nanoparticles is precisely controlled to prepare ordered patterns of nanoparticle assemblies with a high throughput.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Despite the identification of horseshoe bats as the reservoir of severe acute respiratory syndrome (SARS)-related coronaviruses (SARSr-CoVs), the origin of SARS-CoV ORF8, which contains the ...29-nucleotide signature deletion among human strains, remains obscure. Although two SARS-related Rhinolophus sinicus bat CoVs (SARSr-Rs-BatCoVs) previously detected in Chinese horseshoe bats (Rhinolophus sinicus) in Yunnan, RsSHC014 and Rs3367, possessed 95% genome identities to human and civet SARSr-CoVs, their ORF8 protein exhibited only 32.2 to 33% amino acid identities to that of human/civet SARSr-CoVs. To elucidate the origin of SARS-CoV ORF8, we sampled 348 bats of various species in Yunnan, among which diverse alphacoronaviruses and betacoronaviruses, including potentially novel CoVs, were identified, with some showing potential interspecies transmission. The genomes of two betacoronaviruses, SARSr-Rf-BatCoV YNLF_31C and YNLF_34C, from greater horseshoe bats (Rhinolophus ferrumequinum), possessed 93% nucleotide identities to human/civet SARSr-CoV genomes. Although these two betacoronaviruses displayed lower similarities than SARSr-Rs-BatCoV RsSHC014 and Rs3367 in S protein to civet SARSr-CoVs, their ORF8 proteins demonstrated exceptionally high (80.4 to 81.3%) amino acid identities to that of human/civet SARSr-CoVs, compared to SARSr-BatCoVs from other horseshoe bats (23.2 to 37.3%). Potential recombination events were identified around ORF8 between SARSr-Rf-BatCoVs and SARSr-Rs-BatCoVs, leading to the generation of civet SARSr-CoVs. The expression of ORF8 subgenomic mRNA suggested that the ORF8 protein may be functional in SARSr-Rf-BatCoVs. The high Ka/Ks ratio among human SARS-CoVs compared to that among SARSr-BatCoVs supported that ORF8 is under strong positive selection during animal-to-human transmission. Molecular clock analysis using ORF1ab showed that SARSr-Rf-BatCoV YNLF_31C and YNLF_34C diverged from civet/human SARSr-CoVs in approximately 1990. SARS-CoV ORF8 originated from SARSr-CoVs of greater horseshoe bats through recombination, which may be important for animal-to-human transmission.
Although horseshoe bats are the primary reservoir of SARS-related coronaviruses (SARSr-CoVs), it is still unclear how these bat viruses have evolved to cross the species barrier to infect civets and humans. Most human SARS-CoV epidemic strains contain a signature 29-nucleotide deletion in ORF8, compared to civet SARSr-CoVs, suggesting that ORF8 may be important for interspecies transmission. However, the origin of SARS-CoV ORF8 remains obscure. In particular, SARSr-Rs-BatCoVs from Chinese horseshoe bats (Rhinolophus sinicus) exhibited <40% amino acid identities to human/civet SARS-CoV in the ORF8 protein. We detected diverse alphacoronaviruses and betacoronaviruses among various bat species in Yunnan, China, including two SARSr-Rf-BatCoVs from greater horseshoe bats that possessed ORF8 proteins with exceptionally high amino acid identities to that of human/civet SARSr-CoVs. We demonstrated recombination events around ORF8 between SARSr-Rf-BatCoVs and SARSr-Rs-BatCoVs, leading to the generation of civet SARSr-CoVs. Our findings offer insight into the evolutionary origin of SARS-CoV ORF8 protein, which was likely acquired from SARSr-CoVs of greater horseshoe bats through recombination.
L1
0
-FePt nanoparticles (NPs) with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance their catalytic performance in fuel cells. A molecular strategy of ...preparing highly ordered FePt NPs was used by direct pyrolysis of a Fe, Pt-containing bimetallic complex. The resultant L1
0
-FePt NPs had very high crystallinity as reflected by the obvious diffraction patterns, clear lattice fringes and characteristic X-ray diffraction peaks, etc. Besides, the strong ferromagnetism with room temperature coercivity of 27 kOe further confirmed the face-centered tetragonal (fct) phase in good agreement with the ordered nanostructures. The FePt NPs can be used as electrocatalysts to catalyze oxygen reduction reaction (ORR) in an O
2
-saturated 0.1 M HClO
4
solution and hydrogen evolution reaction (HER) in the 0.5 M H
2
SO
4
electrolyte with much better performance than commercial Pt/C, and showed quite high stability after 10,000 cycles. The strategy utilizing organometallic precursors to prepare metal alloy NPs was demonstrated to be a reliable approach for improving the catalytic efficiency in fuel cells.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Crocodile blood has long been used as a traditional medicine in many Asian countries to treat diseases such as asthma, allergies, and many others. Yet, only recently has the safety and effectiveness ...of using crocodile blood as a medicine been examined using modern scientific methods; with both conserved and novel active components identified from crocodile blood. Further in vitro and in vivo investigations found that crocodile blood can have a wide range of beneficial effects, including antimicrobial, antiviral, anti‐oxidative, anti‐inflammatory, antitumour effects, anti‐anaemia, and enhancement of wound healing. A systematic research of literature published in English‐language journals up to April 2020 was conducted in PubMed, Google Scholar, and Web of Science. Based on the biological and chemical knowledge of crocodile immunity and crocodile blood, this article aims to: provide a critical review on the proposed properties of crocodile blood, identify the knowledge gap and offer some insights for future investigations regarding the use of crocodile blood as a medication or dietary supplement.
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DOBA, FSPLJ, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
The stable sandwich structure and the excellent redox activity of ferrocene make it a ubiquitous component in organometallic systems. The introduction of a ferrocenyl unit into a polymer skeleton ...provides a good avenue towards novel materials for various applications in redox batteries, enantioselective catalysis, optical and magnetic switches,
etc.
Herein, we report a strategic design and synthesis of new ferrocene-based hyperbranched polymers, and demonstrate promising methods for their morphology control as spheres by direct coupling reactions and hollow polyhedra by a templating approach. Furthermore, task-specific applications targeted for their respective architectures are investigated in lithium ion batteries (LIBs) and water treatment, respectively. The spherical polymer used as an electroactive anode in LIBs has a high capacity of 755.2 mA h g
−1
, stable chargeable performance of over 200 cycles and superior rate capability. For comparison, the hollow counterpart shows a sharp increase of the specific surface area in the precursor-derived magnetic ceramics from 417 to 1195 m
2
g
−1
, and the as-made material exhibits great potential for the rapid removal of trace amounts of pollutants in water with magnetic reusability.
Ferrocene-based hyperbranched polymers were prepared with different shapes of spheres and hollow polyhedra, and the 3D topological structures were studied as electroactive materials and precursor-derived magnetic ceramics, respectively.
WHO 2016 classified glioblastomas into IDH-mutant and IDH-wildtype with the former having a better prognosis but there was no study on IDH-mutant primary glioblastomas only, as previous series ...included secondary glioblastomas. We recruited a series of 67 IDH-mutant primary glioblastomas/astrocytoma IV without a prior low-grade astrocytoma and examined them using DNA-methylation profiling, targeted sequencing, RNA sequencing and TERT promoter sequencing, and correlated the molecular findings with clinical parameters. The median OS of 39.4 months of 64 cases and PFS of 25.9 months of 57 cases were better than the survival data of IDH-wildtype glioblastomas and IDH-mutant secondary glioblastomas retrieved from datasets. The molecular features often seen in glioblastomas, such as EGFR amplification, combined +7/−10, and TERT promoter mutations were only observed in 6/53 (11.3%), 4/53 (7.5%), and 2/67 (3.0%) cases, respectively, and gene fusions were found only in two cases. The main mechanism for telomere maintenance appeared to be alternative lengthening of telomeres as ATRX mutation was found in 34/53 (64.2%) cases. In t-SNE analyses of DNA-methylation profiles, with an exceptional of one case, a majority of our cases clustered to IDH-mutant high-grade astrocytoma subclass (40/53; 75.5%) and the rest to IDH-mutant astrocytoma subclass (12/53; 22.6%). The latter was also enriched with G-CIMP high cases (12/12; 100%). G-CIMP-high status and MGMT promoter methylation were independent good prognosticators for OS (p = 0.022 and p = 0.002, respectively) and TP53 mutation was an independent poor prognosticator (p = 0.013) when correlated with other clinical parameters. Homozygous deletion of CDKN2A/B was not correlated with OS (p = 0.197) and PFS (p = 0.278). PDGFRA amplification or mutation was found in 16/59 (27.1%) of cases and was correlated with G-CIMP-low status (p = 0.010). Aside from the three well-known pathways of pathogenesis in glioblastomas, chromatin modifying and mismatch repair pathways were common aberrations (88.7% and 20.8%, respectively), the former due to high frequency of ATRX involvement. We conclude that IDH-mutant primary glioblastomas have better prognosis than secondary glioblastomas and have major molecular differences from other commoner glioblastomas. G-CIMP subgroups, MGMT promoter methylation, and TP53 mutation are useful prognostic adjuncts.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Adult medulloblastomas are clinically and molecularly understudied due to their rarity. We performed molecular grouping, targeted sequencing, and TERT promoter Sanger sequencing on a cohort of 99 ...adult medulloblastomas. SHH made up 50% of the cohort, whereas Group 3 (13%) was present in comparable proportion to WNT (19%) and Group 4 (18%). In contrast to paediatric medulloblastomas, molecular groups had no prognostic impact in our adult cohort (p = 0.877). Most frequently mutated genes were TERT (including promoter mutations, mutated in 36% cases), chromatin modifiers KMT2D (31%) and KMT2C (30%), TCF4 (31%), PTCH1 (27%) and DDX3X (24%). Adult WNT patients showed enrichment of TP53 mutations (6/15 WNT cases), and 3/6 TP53-mutant WNT tumours were of large cell/anaplastic histology. Adult SHH medulloblastomas had frequent upstream pathway alterations (PTCH1 and SMO mutations) and few downstream alterations (SUFU mutations, MYCN amplifications). TERT promoter mutations were found in 72% of adult SHH patients, and were restricted to this group. Adult Group 3 tumours lacked hallmark MYC amplifications, but had recurrent mutations in KBTBD4 and NOTCH1. Adult Group 4 tumours harboured recurrent mutations in TCF4 and chromatin modifier genes. Overall, amplifications of MYC and MYCN were rare (3%). Since molecular groups were not prognostic, alternative prognostic markers are needed for adult medulloblastoma. KMT2C mutations were frequently found across molecular groups and were associated with poor survival (p = 0.002). Multivariate analysis identified histological type (p = 0.026), metastasis (p = 0.031) and KMT2C mutational status (p = 0.046) as independent prognosticators in our cohort. In summary, we identified distinct clinical and mutational characteristics of adult medulloblastomas that will inform their risk stratification and treatment.
ObjectivePaediatric living donor liver transplantation (LDLT) has gained popularity due to limited deceased donor organ supply. Some studies report inequalities in donor and recipient gender ...profiles, but data are sparse. We evaluated LDLT donor–recipient gender profiles, comparing country income categories and gender disparity level.DesignWe performed a systematic review, searching PubMed, Embase and Cochrane databases for publications dated January 2006–September 2021. We included full-text English articles reporting gender in ≥40 universally sampled donor–recipient pairs. Search terms were permutations of ‘liver transplant’, ‘living donor’ and ‘paediatric’. Countries were grouped as high/middle/low-income economies based on World Bank criteria and into groups based on deviation from gender parity in Gender Development Index (GDI) values (group 1 indicating closest to gender parity, group 5 indicating furthest). Proportions analysis with corresponding 95% CI were used for analysis of dichotomous variables, with significance when 95% CI did not cross 0.5. Data are reported as female proportion (%) and 95% CI.ResultsOf 12 525 studies identified, 14 retrospective studies (12 countries; 6152 recipients and 6138 donors) fulfilled study inclusion criteria. Male recipient preponderance was seen in lower middle-income countries (all were also GDI group 5) (39.3 (95% CI 34.7 to 44.0)) and female recipient preponderance in GDI groups 1 and 3. Female donor preponderance was seen overall (57.4% (95% CI 55.1 to 59.6)), in middle income countries and in three of four GDI groups represented.ConclusionThere are significant imbalances in recipient-donor gender profiles in paediatric LDLT that are not well explained. The reasons for overall female donor preponderance across income tiers must be scrutinised.
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