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JournalISSN: 2573-2293

ChemRxiv 

American Chemical Society
About: ChemRxiv is an academic journal. The journal publishes majorly in the area(s): Catalysis & Docking (molecular). Over the lifetime, 3079 publications have been published receiving 6754 citations. The journal is also known as: chemrxiv.org.

Papers published on a yearly basis

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Journal ArticleDOI
01 Jan 2021-ChemRxiv
TL;DR: In this paper, it was shown that Fe-N-C catalysts initially comprising two distinct FeNx sites (S1 and S2) degrade via the transformation of S1 into iron oxides while the structure and number of S2 were unmodified.
Abstract: While Fe-N-C materials are a promising alternative to platinum for catalyzing oxygen reduction in acidic polymer fuel cells, limited understanding of their operando degradation restricts rational approaches towards improved durability. Here we show that Fe-N-C catalysts initially comprising two distinct FeNx sites (S1 and S2) degrade via the transformation of S1 into iron oxides while the structure and number of S2 were unmodified. Structure-activity correlations drawn from end-of-test 57Fe Mossbauer spectroscopy reveal that both sites initially contribute to the ORR activity but only S2 significantly contributes after 50 h of operation. From in situ 57Fe Mossbauer spectroscopy in inert gas coupled to calculations of the Mossbauer signature of FeNx moieties in different electronic states, we identify S1 to be a high-spin FeN4C12 moiety and S2 a low- or intermediate spin FeN4C10 moiety. These insights lay the ground for rational approaches towards Fe-N-C cathodes with improved durability in acidic fuel cells.

274 citations

Posted ContentDOI
13 Apr 2020-ChemRxiv
TL;DR: The results showed the ORF8 and surface glycoprotein could bind to the porphyrin, respectively, and the mechanism also interfered with the normal heme anabolic pathway of the human body, which is expected to result in human disease.
Abstract: The novel coronavirus pneumonia (COVID-19) is an infectious acute respiratory infection caused by the novel coronavirus The virus is a positive-strand RNA virus with high homology to bat coronavirus In this study, conserved domain analysis, homology modeling, and molecular docking were used to compare the biological roles of certain proteins of the novel coronavirus The results showed the ORF8 and surface glycoprotein could bind to the porphyrin, respectively At the same time, orf1ab, ORF10, and ORF3a proteins could coordinate attack the heme on the 1-beta chain of hemoglobin to dissociate the iron to form the porphyrin The attack will cause less and less hemoglobin that can carry oxygen and carbon dioxide The lung cells have extremely intense poisoning and inflammatory due to the inability to exchange carbon dioxide and oxygen frequently, which eventually results in ground-glass-like lung images The mechanism also interfered with the normal heme anabolic pathway of the human body, is expected to result in human disease According to the validation analysis of these finds, chloroquine could prevent orf1ab, ORF3a, and ORF10 to attack the heme to form the porphyrin, and inhibit the binding of ORF8 and surface glycoproteins to porphyrins to a certain extent, effectively relieve the symptoms of respiratory distress Favipiravir could inhibit the envelope protein and ORF7a protein bind to porphyrin, prevent the virus from entering host cells, and catching free porphyrins Because the novel coronavirus is dependent on porphyrins, it may originate from an ancient virus Therefore, this research is of high value to contemporary biological experiments, disease prevention, and clinical treatment br

222 citations

Posted ContentDOI
01 Jan 2017-ChemRxiv
TL;DR: ORGANIC as mentioned in this paper is a framework based on Objective-Reinforced Generative Adversarial Networks (ORGAN), capable of producing a distribution over molecular space that matches with a certain set of desirable metrics.
Abstract: Molecular discovery seeks to generate chemical species tailored to very specific needs. In this paper, we present ORGANIC, a framework based on Objective-Reinforced Generative Adversarial Networks (ORGAN), capable of producing a distribution over molecular space that matches with a certain set of desirable metrics. This methodology combines two successful techniques from the machine learning community: a Generative Adversarial Network (GAN), to create non-repetitive sensible molecular species, and Reinforcement Learning (RL), to bias this generative distribution towards certain attributes. We explore several applications, from optimization of random physicochemical properties to candidates for drug discovery and organic photovoltaic material design.

182 citations

Posted ContentDOI
14 Aug 2020-ChemRxiv
TL;DR: In this article, the authors show that including excess aluminum during synthesis of the Ti3AlC2 MAX phase precursor leads to the creation of Ti3C2 grains with improved stoichiometry and crystallinity.
Abstract: One of the primary factors limiting further research and the commercial use of the two-dimensional (2D) MXene titanium carbide (Ti3C2), as well as MXenes in general, is the rate at which freshly made samples oxidize and degrade when stored as aqueous suspensions. Here, we show that including excess aluminum during synthesis of the Ti3AlC2 MAX phase precursor leads to the creation of Ti3AlC2 grains with improved stoichiometry and crystallinity. Ti3C2 nanosheets produced from the improved Ti3AlC2 are of higher quality, as evidenced by their increased resistance to oxidation and an increase in their electrical conductivity to 20,000 S/cm. Our results indicate that defects created during the synthesis of Ti3C2 (and by inference, other MXenes) lead to the previously observed instability. We show that by eliminating those defects results in Ti3C2 that is highly stable in aqueous solutions and in air. Aqueous suspensions of single- to few-layer Ti3C2 flakes produced from the modified Ti3AlC2 have a shelf life of over ten months, compared to one to two weeks for Ti3C2 produced from conventional Ti3AlC2, even when stored in ambient conditions. Freestanding films made from Ti3C2 suspensions stored for ten months show minimal decreases in electrical conductivity and negligible oxidation. Oxidation of the improved Ti3C2 in air initiates at temperatures that are 100-150°C higher than conventional Ti3C2. The observed improvements in both the shelf life and properties of Ti3C2 will facilitate the widespread use of this material.

173 citations

Posted ContentDOI
22 Jul 2020-ChemRxiv
TL;DR: Preclinical experiments reveal 4 (PF-00835231) as a potent inhibitor of CoV-2 3CLpro with suitable pharmaceutical properties to warrant further development as an intravenous treatment for COVID-19.
Abstract: The novel coronavirus disease COVID-19 that emerged in 2019 is caused by the virus SARS CoV-2 and named for its close genetic similarity to SARS CoV-1 that caused severe acute respiratory syndrome (SARS) in 2002. Both SARS coronavirus genomes encode two overlapping large polyproteins which are cleaved at specific sites by a cysteine 3C-like protease (3CLpro) in a post-translational processing step that is critical for coronavirus replication. The 3CLpro sequences for CoV-1 and CoV-2 viruses are 100% identical in the catalytic domain that carries out protein cleavage. A research effort that focused on the discovery of reversible and irreversible ketone-based inhibitors of SARS CoV-1 3CLpro employing ligand-protease structures solved by X-ray crystallography led to the identification of 3 and 4. Preclinical experiments reveal 4 (PF-00835231) as a potent inhibitor of CoV-2 3CLpro with suitable pharmaceutical properties to warrant further development as an intravenous treatment for COVID-19.

148 citations

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Performance
Metrics
No. of papers from the Journal in previous years
YearPapers
20221
20211,161
20201,124
2019526
2018180
201754