Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Location Of Cobalt Impurities In The Surface Oxide Of Stainless Steel 316l And Metal Release In Synthetic Biological Fluids, Xuying Wang, Jonas Hedberg, Heng-Yong Nie, Mark Biesinger, Inger Odnevall, Yolanda S. Hedberg
Location Of Cobalt Impurities In The Surface Oxide Of Stainless Steel 316l And Metal Release In Synthetic Biological Fluids, Xuying Wang, Jonas Hedberg, Heng-Yong Nie, Mark Biesinger, Inger Odnevall, Yolanda S. Hedberg
Chemistry Publications
Since 2021, cobalt (Co) is in Europe classified as carcinogen in quantities exceeding 0.1 wt-%. This affects nickel-rich stainless steels, which contain about 0.2 wt-% Co impurities. Previous findings show the bioaccessibility of Co in stainless steel to be primarily determined by the corrosion resistance. It has been unclear whether Co is distributed heterogeneously in the alloy and the outermost surface and whether a specific location would pose a risk for Co release under specific exposure conditions. This study aimed at locating Co in stainless steel 316L (0.2 wt-% Co) surfaces prior to and after exposure to different synthetic body …
Skin Permeation Of Nickel, Cobalt And Chromium Salts In Ex Vivo Human Skin, Visualized Using Mass Spectrometry Imaging, Lina Hagvall, Masoumeh Dowlatshahi Pour, Jiabao Feng, Moshtak Karma, Yolanda Hedberg, Per Malmberg
Skin Permeation Of Nickel, Cobalt And Chromium Salts In Ex Vivo Human Skin, Visualized Using Mass Spectrometry Imaging, Lina Hagvall, Masoumeh Dowlatshahi Pour, Jiabao Feng, Moshtak Karma, Yolanda Hedberg, Per Malmberg
Chemistry Publications
Skin permeation and distribution of three of the most common skin sensitizers was investigated using a previ-ously developed animal-free exposure method combined with imaging mass spectrometry. Nickel, cobalt, and chromium (III) salts were dissolved in a buffer and exposed to human skin ex vivo, to be analyzed using time of flight secondary ion mass spectrometry (ToF-SIMS). Our findings demonstrate that metal haptens mainly accumulated in the stratum corneum, however all three metal sensitizers could also be detected in the epidermis. Cobalt and chromium (III) species penetrated into the epidermis to a larger extent than nickel species. The degree of penetration …
Gram Scale Synthesis Of The C(18)-C(34) Fragment Of Amphidinolide C., Nicholas A Morra, Brian L Pagenkopf
Gram Scale Synthesis Of The C(18)-C(34) Fragment Of Amphidinolide C., Nicholas A Morra, Brian L Pagenkopf
Chemistry Publications
The synthesis of the C(18)-C(34) fragment of amphidinolide C has been achieved via two routes, culminating in both the shortest (11 steps) and highest yielding (26% overall yield) approaches to this segment. The highly convergent approach will facilitate the synthesis of analogues, including the C(18)-C(29) fragment of amphidinolide F. Synthetic highlights include the selective methylation of a diyne, and the highly efficient use of a second generation cobalt catalyst in the Mukaiyama oxidative cyclization to form the trans-THF ring.
Gram Scale Synthesis Of The C(18)-C(34) Fragment Of Amphidinolide C., Nicholas A Morra, Brian L Pagenkopf
Gram Scale Synthesis Of The C(18)-C(34) Fragment Of Amphidinolide C., Nicholas A Morra, Brian L Pagenkopf
Chemistry Publications
The synthesis of the C(18)-C(34) fragment of amphidinolide C has been achieved via two routes, culminating in both the shortest (11 steps) and highest yielding (26% overall yield) approaches to this segment. The highly convergent approach will facilitate the synthesis of analogues, including the C(18)-C(29) fragment of amphidinolide F. Synthetic highlights include the selective methylation of a diyne, and the highly efficient use of a second generation cobalt catalyst in the Mukaiyama oxidative cyclization to form the trans-THF ring.
Increased Yields And Simplified Purification With A Second-Generation Cobalt Catalyst For The Oxidative Formation Of Trans-Thf Rings., Cory Palmer, Nicholas A Morra, Andrew C Stevens, Barbora Bajtos, Ben P Machin, Brian L Pagenkopf
Increased Yields And Simplified Purification With A Second-Generation Cobalt Catalyst For The Oxidative Formation Of Trans-Thf Rings., Cory Palmer, Nicholas A Morra, Andrew C Stevens, Barbora Bajtos, Ben P Machin, Brian L Pagenkopf
Chemistry Publications
The synthesis of a second-generation cobalt catalyst for the formation of trans-THF products via the Mukaiyama aerobic oxidative cyclization is reported. Two procedures have been developed with the new water-soluble catalyst that give superior yields and greatly simplify purification compared to the previous catalysts.
Synthesis And First X-Ray Structures Of Cobalt(Ii) And Cobalt(Iii) Complexes Bearing 2,4-Dioxo-Alkanoic Acid Dialkylamide Ligands, Brian Pagenkopf, Jian Wang, Nicholas A. Morra, Hongda Zhao, Vincent Lynch, Robert Mcdonald, John F. Reichwein
Synthesis And First X-Ray Structures Of Cobalt(Ii) And Cobalt(Iii) Complexes Bearing 2,4-Dioxo-Alkanoic Acid Dialkylamide Ligands, Brian Pagenkopf, Jian Wang, Nicholas A. Morra, Hongda Zhao, Vincent Lynch, Robert Mcdonald, John F. Reichwein
Chemistry Publications
The aerobic oxidation of 5-hydroxy pentenes to trans-tetrahydrofurans (THFs), the Mukaiyama oxidation, has in recent years emerged as a powerful tool in synthetic chemistry. In this report we describe the first crystal structures of 2,4-dioxo-alkanoic acid dialkylamide complexes for both Co(II) and Co(III) salts. The Co(II) structures show an unprecedented arrangement of atoms, with a central Co(II)(H2O)6 flanked by two Co(II) atoms each coordinated with three anionic chelating ligands. The dimeric Co(III) structures show two anionic chelating ligands and bridging hydroxyl groups.