loading Please wait. Data is being processed...

News of Inventions: 345673
Files of Inventions: 220
Groups of Inventors: 50

Friend Requests:
Private Messages:

Today's News: 28
Yesterday's News: 107

Today: 11 April 2021, Sunday.

All latest news of Inventions in one place

Listed news of Inventions: 9 from total 345673

Filters


Welcome, Guest

News for Chemicals





#1

 

View it
Name
Description TBD

#Chemicals
Field # Chemicals
Updated 10 April 2021

#2

 

View it
Name
Description TBD

#Chemicals
Field # Chemicals
Updated 09 April 2021

#3

 

View it
Name
Description New Scientist's weekly round-up of the best books, films, TV series, games and more that you shouldn’t miss

#Chemicals
Field # Chemicals
Updated 09 April 2021

#4

 

View it
Name
Description The asymmetric construction of all-carbon quaternary centres within acyclic settings represents a long-standing challenge for synthetic chemists. Alongside polar and radical methods, rearrangement reactions represent an attractive platform, but still broadly applicable methods are in high demand. Here we report an asymmetric, radical sulfinyl-Smiles rearrangement to access acyclic amides that bear an α-all-carbon quaternary centre. Our strategy uses enantioenriched N-arylsulfinyl acrylamides as acceptors for a variety of radicals produced in situ under mild photoredox conditions. The sulfinamido group not only directs the 1,4-migration of the aryl moiety onto the α-carbon of the amide, which thus governs its absolute configuration, but also functions as a traceless chiral auxiliary. The amides obtained in this multicomponent process are prevalent in pharmaceuticals, agrochemicals and bioactive natural products, and can be transformed into valuable chiral α,α-disubstituted acids, oxindoles as well as into β,β-disubstituted amines, highlighting the synthetic potential of this transformation. The assembly of a single configuration of an all-carbon quaternary centre within acyclic systems remains a challenge for synthetic chemists. Now, it has been shown that α-all-carbon quaternary centres can be installed in acyclic amides, with excellent levels of absolute stereocontrol, through a radical sulfinyl Truce–Smiles rearrangement.

#Chemicals
Field # Chemicals
Updated 08 April 2021

#5

 

View it
Name
Description Regarding their resistance five sealants were tested in vitro after experiencing mechanical, thermal and chemical stress. Included for testing were two fluoride varnishes: Fluor Protector [FP] (Ivoclar Vivadent) and Protecto CaF2 Nano One-Step Seal [PN] (BonaDent) and three fluoride-composite filled sealants (with acid etch technique): Clinpro XT Varnish [CP] (3 M Espe), Pro Seal [PS] & Light Bond [LB] (Reliance Orthodontic Products) and a positive control group [CG] Tetric EvoFlow (Ivoclar Vivadent). The sealants were applied on 180 bovine teeth (n = 10/ sealer) in a standardized manner after bracket bonding. Mechanical pressure and its effect by simulating different time points and standardized electric cleaning protocol was tested first. Followed by thermal burden due to varying thermal stress and thirdly change in pH stress imitating chemical exposure were examined separately. A digital microscope and a grid incisal and apical to the brackets (n = 32 fields) was used to standardize the optical analysis. Material loss due to mechanical stress compared to CG (score 0.00) was CP (1.2%), FP (21.5%), LB (22.2%) and PN (81.1%). No significant difference to CG presented PS. Material loss due to thermal stress was CP (0.5%), PS (2%), FP (2.6%), LB (3.1%) and PN (39.9%). Material loss due to chemical stress was FP (1.8%), PS (2.1%), LB (5.5%) and PN (39.6%). No significant difference to CG presented CP. Only PS and CP had optically provable, good resiliance to mechanical, thermal and chemical stress. Significantly poorer outcomes in particular showed PN.

#Chemicals
Field # Chemicals
Updated 07 April 2021

#6

 

View it
Name
Description 3D-printing tough conductive hydrogels (TCHs) with complex structures is still a challenging task in related fields due to their inherent contrasting multinetworks, uncontrollable and slow polymerization of conductive components. Here we report an orthogonal photochemistry-assisted printing (OPAP) strategy to make 3D TCHs in one-pot via the combination of rational visible-light-chemistry design and reliable extrusion printing technique. This orthogonal chemistry is rapid, controllable, and simultaneously achieve the photopolymerization of EDOT and phenol-coupling reaction, leading to the construction of tough hydrogels in a short time (tgel ~30 s). As-prepared TCHs are tough, conductive, stretchable, and anti-freezing. This template-free 3D printing can process TCHs to arbitrary structures during the fabrication process. To further demonstrate the merits of this simple OPAP strategy and TCHs, 3D-printed TCHs hydrogel arrays and helical lines, as proofs-of-concept, are made to assemble high-performance pressure sensors and a temperature-responsive actuator. It is anticipated that this one-pot rapid, controllable OPAP strategy opens new horizons to tough hydrogels. 3D-printing tough conductive hydrogels (TCHs) with complex structures is still a challenging task due to their inherent contrasting multinetworks, uncontrollable and slow polymerization. Here the authors show an orthogonal photochemistry-assisted printing strategy to make 3D TCHs in one pot.

#Chemicals
Field # Chemicals
Updated 07 April 2021

#7

 

View it
Name
Description The formation of all-carbon quaternary centres is a challenging problem in organic chemistry, with far-reaching implications for functional molecule discovery. Now an inventive solution has been developed, using sulfinamides as traceless linkers for an asymmetric radical Truce–Smiles rearrangement.

#Chemicals
Field # Chemicals
Updated 07 April 2021

#8

 

View it
Name
Description Biotin is an essential micro-nutrient across the three domains of life. The paradigm earlier step of biotin synthesis denotes “BioC-BioH” pathway in Escherichia coli. Here we report that BioZ bypasses the canonical route to begin biotin synthesis. In addition to its origin of Rhizobiales, protein phylogeny infers that BioZ is domesticated to gain an atypical role of β-ketoacyl-ACP synthase III. Genetic and biochemical characterization demonstrates that BioZ catalyzes the condensation of glutaryl-CoA (or ACP) with malonyl-ACP to give 5’-keto-pimeloyl ACP. This intermediate proceeds via type II fatty acid synthesis (FAS II) pathway, to initiate the formation of pimeloyl-ACP, a precursor of biotin synthesis. To further explore molecular basis of BioZ activity, we determine the crystal structure of Agrobacterium tumefaciens BioZ at 1.99 Å, of which the catalytic triad and the substrate-loading tunnel are functionally defined. In particular, we localize that three residues (S84, R147, and S287) at the distant bottom of the tunnel might neutralize the charge of free C-carboxyl group of the primer glutaryl-CoA. Taken together, this study provides molecular insights into the BioZ biotin synthesis pathway. Biotin is an essential enzyme cofactor and two pathways for the generation of the biotin precursor pimeloyl-ACP are known. Here, the authors identify and characterize a third pathway for biotin precursor synthesis involving BioZ and they also present the Agrobacterium tumefaciens BioZ crystal structure.

#Chemicals
Field # Chemicals
Updated 06 April 2021

#9

 

View it
Name
Description FeS2/TiO2 nanotube array composite films with clean, high efficiency, low cost and low consumption were prepared by electrochemical anodization and hydrothermal methods. The modification of FeS2 nanoparticles on the surface of TiO2 nanotube array film not only broadens the light absorption range of TiO2, but also improves the utilization ratio of visible light and the separation rate of photogenerated electron–hole pairs, which greatly improves the photoelectrochemical cathodic protection performance of TiO2 for 304 stainless steel (304SS). Under visible light irradiation, the open circuit potential of 304SS coupled with the FeS2/TiO2 nanocomposite films decreased from − 170 to − 700 mV, and the electrode potential can still maintained at − 400 mV after the light was turned off. Compared with pure TiO2 nanotube array film, FeS2/TiO2 nanocomposite film has better photoelectrochemical cathodic protection effect on 304SS in 3.5 wt% NaCl corrosion medium.

#Chemicals
Field # Chemicals
Updated 05 April 2021