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The ammonia-oxidizing archaeon Nitrososphaera gargensis can utilize cyanate as the only source of energy for growth due to the presence of a cyanase enzyme, and cyanase-encoding nitrite-oxidizing bacteria can work together with cyanase-negative ammonia oxidizers to collectively grow on cyanate via reciprocal feeding; cyanases are widespread in the environment according to metagenomic data sets, pointing to the potential importance of cyanate in the nitrogen cycle. Cyanate an unexpected energy source Nitrification is a central process in the global nitrogen cycle and plays a major role in fertilizer loss in industrial agriculture. Here Michael Wagner and colleagues report that the ammonia-oxidizing archaeon Nitrosphaera gargensis can grow on cyanate as its sole energy source — possibly the only known organism capable of doing so. The archaeon converts cyanate to ammonium and carbon dioxide using a cyanase enzyme. Further investigation of metagenomes shows that cyanases are widespread in the environment. This work highlights the potential importance of cyanate in the nitrogen cycle as a source of reduced nitrogen in the environment. Ammonia- and nitrite-oxidizing microorganisms are collectively responsible for the aerobic oxidation of ammonia via nitrite to nitrate and have essential roles in the global biogeochemical nitrogen cycle. The physiology of nitrifiers has been intensively studied, and urea and ammonia are the only recognized energy sources that promote the aerobic growth of ammonia-oxidizing bacteria and archaea. Here we report the aerobic growth of a pure culture of the ammonia-oxidizing thaumarchaeote Nitrososphaera gargensis 1 using cyanate as the sole source of energy and reductant; to our knowledge, the first organism known to do so. Cyanate, a potentially important source of reduced nitrogen in aquatic and terrestrial ecosystems 2 , is converted to ammonium and carbon dioxide in Nitrososphaera gargensis by a cyanase enzyme that is induced upon addition of this compound. Within the cyanase gene family, this cyanase is a member of a distinct clade also containing cyanases of nitrite-oxidizing bacteria of the genus Nitrospira. We demonstrate by co-culture experiments that these nitrite oxidizers supply cyanase-lacking ammonia oxidizers with ammonium from cyanate, which is fully nitrified by this microbial consortium through reciprocal feeding. By screening a comprehensive set of more than 3,000 publically available metagenomes from environmental samples, we reveal that cyanase-encoding genes clustering with the cyanases of these nitrifiers are widespread in the environment. Our results demonstrate an unexpected metabolic versatility of nitrifying microorganisms, and suggest a previously unrecognized importance of cyanate in cycling of nitrogen compounds in the environment.

We synthesised coumarin-based derivatives bearing thio- and selenocyanates to selectively inhibit tumour-associated carbonic anhydrases (CAs) IX and XII and to exert antiproliferative effects on tumour cells. Structural variations included chalcogen atom type (S, Se), substitutions at C-3/C-4, and tether length at C-7 of the coumarin core. Thiocyanates and showed potent CA IX/XII inhibition ( = 17.9-27.4 nM) with >5000-fold selectivity over off-target isoforms (CAs I and II). Selenocyanate exhibited strong antiproliferative activity (GI = 0.78-2.6 µM) across six human solid tumour cell lines. Mechanistic studies revealed a cytostatic effect cell cycle arrest and reduced mitotic progression. assays in confirmed selective cytostatic action of selenocyanate , reducing tumorous germline size without affecting healthy tissues at therapeutic doses.

Perovskite bandgap tuning without quality loss makes perovskites unique among solar absorbers, offering promising avenues for tandem solar cells 1 , 2 . However, minimizing the voltage loss when their bandgap is increased to above 1.90 eV for triple-junction tandem use is challenging 3 – 5 . Here we present a previously unknown pseudohalide, cyanate (OCN − ), with a comparable effective ionic radius (1.97 Å) to bromide (1.95 Å) as a bromide substitute. Electron microscopy and X-ray scattering confirm OCN incorporation into the perovskite lattice. This contributes to notable lattice distortion, ranging from 90.5° to 96.6°, a uniform iodide–bromide distribution and consistent microstrain. Owing to these effects, OCN-based perovskite exhibits enhanced defect formation energy and substantially decreased non-radiative recombination. We achieved an inverted perovskite (1.93 eV) single-junction device with an open-circuit voltage ( V OC ) of 1.422 V, a V OC  × FF (fill factor) product exceeding 80% of the Shockley–Queisser limit and stable performance under maximum power point tracking, culminating in a 27.62% efficiency (27.10% certified efficiency) perovskite–perovskite–silicon triple-junction solar cell with 1 cm 2 aperture area. Triple-junction solar cells with cyanate in ultrawide-bandgap perovskites exhibit enhanced defect formation energy and substantially decreased non-radiative recombination.

Chemical recycling of polymers is critical for improving the circular economy of plastics and environmental sustainability. Traditional thermoset polymers have generally been considered permanently crosslinked materials that are difficult or impossible to recycle. Herein, we demonstrate that by activating ‘dormant’ covalent bonds, traditional polycyanurate thermosets can be recycled into the original monomers, which can be circularly reused for their original purpose. Through retrosynthetic analysis, we redirected the synthetic route from forming conventional C–N bonds via irreversible cyanate trimerization to forming the C–O bonds through reversible nucleophilic aromatic substitution of alkoxy-substituted triazine derivatives by alcohol nucleophiles. The new reversible synthetic route enabled the synthesis of previously inaccessible alkyl-polycyanurate thermosets, which exhibit excellent film properties with high chemical resistance, closed-loop recyclability and reprocessing capability. These results show that ‘apparently dormant’ dynamic linkages can be activated and utilized to construct fully recyclable thermoset polymers with a broader monomer scope and increased sustainability. Alkyl and aryl polycyanurate networks have now been prepared through polymerization of diols and substituted triazines via a dynamic S N Ar reaction. When treated with excess mono alcohol or phenol, the polycyanurate networks can be depolymerized into the starting monomers, which can be separated and reused, thus achieving closed-loop recycling.

(Thio)ureas ((T)Us) and benzothiazoles (BTs) each have demonstrated to have a great variety of biological activities. When these groups come together, the 2-(thio)ureabenzothizoles [(T)UBTs] are formed, improving the physicochemical as well as the biological properties, making these compounds very interesting in medicinal chemistry. Frentizole, bentaluron and methabenzthiazuron are examples of UBTs used for treatment of rheumatoid arthritis and as wood preservatives and herbicides in winter corn crops, respectively. With this antecedent, we recently reported a bibliographic review about the synthesis of this class of compounds, from the reaction of substituted 2-aminobenzothiazoles (ABTs) with iso(thio)cyanates, (thio)phosgenes, (thio)carbamoyl chlorides, 1,1’-(thio)carbonyldiimidazoles, and carbon disulfide. Herein, we prepared a bibliographic review about those features of design, chemical synthesis, and biological activities relating to (T)UBTs as potential therapeutic agents. This review is about synthetic methodologies generated from 1968 to the present day, highlighting the focus to transform (T)UBTs to compounds containing a range substituents, as illustrated with 37 schemes and 11 figures and concluded with 148 references. In this topic, the scientists dedicated to medicinal chemistry and pharmaceutical industry will find useful information for the design and synthesis of this interesting group of compounds with the aim of repurposing these compounds.

Electrochemical urea oxidation offers a sustainable avenue for H 2 production and wastewater denitrification within the water-energy nexus; however, its wide application is limited by detrimental cyanate or nitrite production instead of innocuous N 2 . Herein we demonstrate that atomically isolated asymmetric Ni–O–Ti sites on Ti foam anode achieve a N 2 selectivity of 99%, surpassing the connected symmetric Ni–O–Ni counterparts in documented Ni-based electrocatalysts with N 2 selectivity below 55%, and also deliver a H 2 evolution rate of 22.0 mL h –1 when coupled to a Pt counter cathode under 213 mA cm –2 at 1.40 V RHE . These asymmetric sites, featuring oxygenophilic Ti adjacent to Ni, favor interaction with the carbonyl over amino groups in urea, thus preventing premature resonant C⎓N bond breakage before intramolecular N–N coupling towards N 2 evolution. A prototype device powered by a commercial Si photovoltaic cell is further developed for solar-powered on-site urine processing and decentralized H 2 production. Urea electrooxidation often produces harmful cyanates and nitrites instead of N2, limiting its use in wastewater denitrification. Here, the authors develop an asymmetric Ni–O–Ti catalytic sites on Ti foam that reduce these byproducts, achieve 99% N2 selectivity, and boost H2 evolution.

Low cost superhydrophobic cotton fabric was developed using TiO2/cyanate ester coating for the first time. The TiO2/cyanate ester coated cotton fabric displayed superhydrophobic behaviour with water contact angle of 158°, sliding contact angle of 8° and surface free energy of 18.0 mN/m2. Besides, the TiO2/cyanate ester coated cotton fabric also possesses excellent laundry durability as well as stability against acid, alkali salt solutions and mechanical abrasion. Consequently, the TiO2/cyanate ester coated cotton also delivered superior oil–water separation efficiency with different types of oil/water mixtures that includes engine oil/water, waste engine oil/water, petrol/water and diesel/water. The TiO2/cyanate ester coated cotton fabric shows separation efficiency as high as 98% with flux value of 7200 L/m2h for petrol/water mixture. Further, both cyanate ester and TiO2/cyanate ester coated cotton fabric delivers ultra-high UV-resistant ability with Ultraviolet Protection Factor value as high as 500 + . Hence, it is anticipated that the present approach of using cyanate ester can be widely explored further to construct multifunctional fabrics towards excellent self-cleaning as well as oil/water separation with UV and chemical robustness.

The dramatic cardiovascular mortality of patients with chronic kidney disease is attributable in a significant proportion to endothelial dysfunction. Cyanate, a reactive species in equilibrium with urea, is formed in excess in chronic kidney disease. Cyanate is thought to have a causal role in promoting cardiovascular disease, but the underlying mechanisms remain unclear. Immunohistochemical analysis performed in the present study revealed that carbamylated epitopes associate mainly with endothelial cells in human atherosclerotic lesions. Cyanate treatment of human coronary artery endothelial cells reduced expression of endothelial nitric oxide synthase, and increased tissue factor and plasminogen activator inhibitor-1 expression. In mice, administration of cyanate, promoting protein carbamylation at levels observed in uremic patients, attenuated arterial vasorelaxation of aortic rings in response to acetylcholine without affecting the sodium nitroprusside–induced relaxation. Total endothelial nitric oxide synthase and nitric oxide production were significantly reduced in aortic tissue of cyanate-treated mice. This coincided with a marked increase of tissue factor and plasminogen activator inhibitor-1 protein levels in aortas of cyanate-treated mice. Thus, cyanate compromises endothelial functionality in vitro and in vivo. This may contribute to the dramatic cardiovascular risk of patients suffering from chronic kidney disease.

Ammonia-oxidizing archaea of the phylum Thaumarchaeota are among the most abundant marine microorganisms 1 . These organisms thrive in the oceans despite ammonium being present at low nanomolar concentrations 2 , 3 . Some Thaumarchaeota isolates have been shown to utilize urea and cyanate as energy and N sources through intracellular conversion to ammonium 4 – 6 . Yet, it is unclear whether patterns observed in culture extend to marine Thaumarchaeota, and whether Thaumarchaeota in the ocean directly utilize urea and cyanate or rely on co-occurring microorganisms to break these substrates down to ammonium. Urea utilization has been reported for marine ammonia-oxidizing communities 7 – 10 , but no evidence of cyanate utilization exists for marine ammonia oxidizers. Here, we demonstrate that in the Gulf of Mexico, Thaumarchaeota use urea and cyanate both directly and indirectly as energy and N sources. We observed substantial and linear rates of nitrite production from urea and cyanate additions, which often persisted even when ammonium was added to micromolar concentrations. Furthermore, single-cell analysis revealed that the Thaumarchaeota incorporated ammonium-, urea- and cyanate-derived N at significantly higher rates than most other microorganisms. Yet, no cyanases were detected in thaumarchaeal genomic data from the Gulf of Mexico. Therefore, we tested cyanate utilization in Nitrosopumilus maritimus , which also lacks a canonical cyanase, and showed that cyanate was oxidized to nitrite. Our findings demonstrate that marine Thaumarchaeota can use urea and cyanate as both an energy and N source. On the basis of these results, we hypothesize that urea and cyanate are substrates for ammonia-oxidizing Thaumarchaeota throughout the ocean. Thaumarchaeota isolates are capable of utilizing urea and cyanate for nitrification in vitro. Here, the authors show that this occurs in situ and that Thaumarchaeota are able to use urea and cyanate as an energy and nitrogen source in the marine environment.

Researching low-temperature curing cyanate ester resin systems is highly significant. This paper uses bisphenol A cyanate ester as the research subject and conducts a study on curing cyanate ester resin materials at 135 °C. The thesis systematically investigates how catalyst activity and dosage affect various properties of the resin castings, specifically dielectric, mechanical, and thermal properties. Through screening of amine-based catalysts, two effective catalysts were identified: organic urea (Dyhard UR300) and bis(2-(dimethylamino)ethyl) ether. Additionally, optimizing the catalyst dosage revealed that 2 mol% provides effective catalysis. Based on a 2 mol% dosage of bis(2-(dimethylamino)ethyl) ether, the effect of curing time on the degree of cure of the resin casting was investigated. At 135 °C, after 10 hours of curing, the resin casting achieves a high degree of cure at 86.3%.