PubChem (https://pubchem.ncbi.nlm.nih.gov) is a public repository for information on chemical substances and their biological activities, launched in 2004 as component of the Molecular Libraries Roadmap Initiatives US National Institutes Health (NIH). For past 11 years, has grown to sizable system, serving resource scientific research community. consists three inter-linked databases, Substance, Compound BioAssay. The Substance database contains deposited by individual data contributors...

PubChem (https://pubchem.ncbi.nlm.nih.gov) is a popular chemical information resource that serves the scientific community as well general public, with millions of unique users per month. In past two years, made substantial improvements. Data from more than 100 new data sources were added to PubChem, including chemical-literature links Thieme Chemistry, and physical property SpringerMaterials, patent World Intellectual Properties Organization (WIPO). PubChem's homepage individual record...

PubChem (https://pubchem.ncbi.nlm.nih.gov) is a key chemical information resource for the biomedical research community. Substantial improvements were made in past few years. New data content was added, including spectral information, scientific articles mentioning chemicals, and food agricultural chemicals. released new web interfaces, such as Target View page, Sources Bioactivity dyad pages Patent page. also major update to Widgets introduced programmatic access interface, called PUG-View....

Abstract PubChem (https://pubchem.ncbi.nlm.nih.gov) is a popular chemical information resource that serves wide range of use cases. In the past two years, number changes were made to PubChem. Data from more than 120 data sources was added Some major highlights include: integration Google Patents into PubChem, which greatly expanded coverage Patent collection; creation Cell Line and Taxonomy collections, provide quick easy access for given cell line taxon, respectively; update bioassay model....

PubChem (http://pubchem.ncbi.nlm.nih.gov) is a public repository for biological activity data of small molecules and RNAi reagents. The mission to deliver free easy access all deposited data, provide intuitive analysis tools. BioAssay database currently contains 500 000 descriptions assay protocols, covering 5000 protein targets, 30 gene targets providing over 130 million bioactivity outcomes. PubChem's bioassay are integrated into the NCBI Entrez information retrieval system, thus making...

PubChem's BioAssay database (https://pubchem.ncbi.nlm.nih.gov) has served as a public repository for small-molecule and RNAi screening data since 2004 providing open access of its content to the community. PubChem accepts submission from worldwide researchers at academia, industry government agencies. also collaborates with other chemical biology stakeholders exchange. With over decade's development effort, it becomes an important information resource supporting drug discovery research. To...

PubChem's BioAssay database (http://pubchem.ncbi.nlm.nih.gov) is a public repository for archiving biological tests of small molecules generated through high-throughput screening experiments, medicinal chemistry studies, chemical biology research and drug discovery programs. In addition, the contains data from RNA interference aimed at identifying critical genes responsible process or disease condition. The mission PubChem to serve community by providing free easy access all deposited data....

Abstract PubChem (https://pubchem.ncbi.nlm.nih.gov) is a large and highly-integrated public chemical database resource at NIH. In the past two years, significant updates were made to PubChem. With additions from over 130 new sources, contains >1000 data 119 million compounds, 322 substances 295 bioactivities. New interfaces, such as consolidated literature panel patent knowledge panel, developed. The combines all references about compound into single list, allowing users easily find,...

PubChem (https://pubchem.ncbi.nlm.nih.gov) is a public chemical database at the U.S. National Institutes of Health. Visited by millions users every month, it plays role as key information resource for biomedical research communities. Data in from hundreds contributors and organized into multiple collections record type. Among these are Protein, Gene, Pathway, Taxonomy data collections. Records contain on chemicals related to given biological target (i.e., protein, gene, pathway, or taxon),...

We have investigated the heretofore unknown unimolecular decomposition pathway of explosive molecule diaminodinitroethylene (DADNE). With use DFT methods, whose accuracy has been calibrated by means ab initio calculations (MP2, MP4, G2) on a simpler but related molecule, nitroethylene, we able to characterize entire reaction pathway. Importantly, find that is initiated nitro-to-nitrite rearrangement with calculated energy barrier magnitude 59.1 kcal/mol obtained B3LYP (59.7 B3P86) which very...

In the search for boron nanotubes, geometrical duals of carbon we employ Euler−Poincare formula a cylinder, P − C + F = 0. As may be seen in attached figure, nanotubes imagined as arising from correspondence between atom and center each faces nanotube.

Using quantum mechanics and exploiting known crystallographic coordinates of tRNA substrate located in the ribosome peptidyl transferase center around 2-fold axis, we have investigated mechanism for peptide-bond formation. The calculation is based on a choice 50 atoms assumed to be important mechanism. We used density functional theory optimize geometry energy transition state (TS) TS formed simultaneously with rotatory motion enabling translocation A-site 3' end into P site, estimated...

PubChem is a chemical data repository that provides comprehensive information on various entities. It contains wealth of from hundreds sources. Programmatic access to this large amount researchers with new opportunities for data-intensive research. several programmatic routes. One these PUG-View, which Representational State Transfer (REST)-style web service interface specialized accessing annotation contained in PubChem. The present paper describes aspects including the scope accessible...

The literature knowledge panels developed and implemented in PubChem are described. These help to uncover summarize important relationships between chemicals, genes, proteins, diseases by analyzing co-occurrences of terms biomedical abstracts. Named entities PubMed records matched with chemical names PubChem, disease Medical Subject Headings (MeSH), gene/protein popular information resources, the most closely related identified using statistical analysis relevance-based sampling. Knowledge...

Abstract Twenty 4‐acyl‐5‐pyrazolonato (Q) titanium derivatives of varied nuclearity have been synthesized from Ti(OR) 4 or TiCl and characterized with spectroscopic methods (IR, NMR, ESI‐MS). While Ti−(β‐diketonato) cleavage is not seen in isolated solids, Ti−O(alkoxy) (or Ti−Cl) bonds cleave upon hydrolysis, leading to several structural forms, including oligomers. Ionic Q species no Ti, i.e., obtained after Ti−Q cleavage, are for some by ESI‐MS, which also indicates a given species, e.g.,...

Four distinct pathways of unimolecular decomposition nitroethylene, the C−NO2 bond breaking, nitro-to-nitrite rearrangement, 1,2-elimination reaction and 1,1-elimination reaction, have been computationally investigated with ab initio, MP2, MP4, G2 methods as well DFT methods. The rearrangement are found to give lowest energy for this molecule, about 15 kcal/mol lower than cleavage nitro group.

PubMed is a freely accessible system for searching the biomedical literature, with ∼2.5 million users worldwide on an average workday. In order to better meet our users' needs in era of information overload, we have recently developed Labs (www.pubmed.gov/labs), experimental test new search features/tools (e.g. Best Match) and provide feedback, which enables us make more informed decisions about potential changes improve quality overall usability PubMed. addition, features mobile-first...

Abstract PubChem ( https://pubchem.ncbi.nlm.nih.gov ) is one of the top five most visited chemistry web sites in world, with more than million unique users per month (as March 2020). Many these are educators, undergraduate students, and graduate students at academic institutions. Therefore, has a great potential as an online resource for chemical education. This paper describes Periodic Table Element pages, which were recently introduced to celebrate 150th anniversary periodic table. These...

The Descartes−Euler formula, P + F = C 2, which is known to apply single cage carbon and boron fullerenes, shown here multicage fullerenes as well. Every fullerene has a corresponding geometrical dual, of identical symmetry, for example in the case C47 B30H302-, here. proposed are studied with molecular orbital calculations establish their energetic stability, bond lengths, ionic charge state.

Spacecraft flying in low Earth orbit (LEO) are exposed to a harsh environment which includes frequent bombardment by fast atomic oxygen (AO) and ultraviolet (UV) radiation. As result, many spacecraft surface materials severely eroded. In the case of fluoropolymers, controversy exists whether AO or UV AO/UV synergy is responsible for degradation. this study, with use ab initio calculations, we address question most abundant species LEO, viz., its ground state, O(3P), alone can cause...

O(3P) is a highly reactive species which may cause damage to materials on contact. In low Earth orbit (LEO), high-energy collisions (∼4.5 eV) of with spacecraft can lead extensive degradation. this study, we use ab initio molecular orbital calculations investigate the possibility chain breaking in polyethylene caused by single attack under LEO conditions, because occurrence such reactions could greatly accelerate erosion. The smallest alkanes (n = 2, 3, 5, or 7) serve as models polyethylene....

Six-coordinate organotin derivatives L2SnR2 [L = 3-methyl-1-(4-trifluoromethylphenyl)-4-R3-C=O-5-pyrazolonato (R3 CH3, L L1; R3 C6H5, L2; CF3, L3; R n-C4H9, C6H5)] have been synthesized and characterized by analytical spectroscopic (1H, 13C, 119Sn, 19F NMR, IR) techniques. Partial dissociation of one ligand in chloro-hydrocarbon solvents gives rise to cationic five-coordinate L-(solvent)-diorganotin(IV) complexes. The X-ray crystal structure...

Diorganotin(IV) complexes of the β-diketonato benzoylacetonato ligand were synthesized and characterized with IR multinuclear (H, C, Sn) NMR spectroscopy. The X-ray diffraction study bis(benzoylacetonato)di-tert-butyltin(IV) shows two independent molecules in crystallographic unit cell. metal polyhedron is a distorted octahedral (Skewed Trapezoidal Bipyramidal) trans angle C−Sn−C 151.5(5)°. Each chelates different donor abilities [Sn−O bond lengths 2.423(8) Å 2.135(8) one ligand, 2.107(9)...