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WHAT IS DASH?
DASH is the central, open-access institutional repository of research by members of the Harvard community. Harvard Library Open Scholarship and Research Data Services (OSRDS) operates DASH to provide the broadest possible access to Harvard's scholarship. This repository hosts a wide range of Harvard-affiliated scholarly works, including pre- and post-refereed journal articles, conference proceedings, theses and dissertations, working papers, and reports.
More about DASHRecent Submissions
Effects of Pd ensemble size in dilute and single atom alloy PdAu catalysts for one-pot selective hydrogenation and reductive amination
(Royal Society of Chemistry, 2025-06-06) Lim, Kang Rui Garrick; Toghrul Azizli; Selina K. Kaiser; Aizenberg, Michael; Montemore, Matthew; Aizenberg, Joanna
In the one-pot reaction between nitroarenes, aldehydes, and hydrogen, the desired outcome is the selective hydrogenation of nitroarenes to form aminoarenes that condense with aldehydes to form pharmaceutically relevant imines and N-alkylamines. One approach to facilitate the selective hydrogenation of nitroarenes over aldehydes involves using bimetallic catalysts with near equimolar ratios. However, structural characterization of metallic ensembles on the nanoparticle surface is challenging at such high alloying ratios, which hinders the elucidation of clear structure–property relationships. Here, we prepared a well-controlled series of dilute Pd-in-Au alloy catalysts with a fixed nanoparticle size as a model system to investigate the effects of surface Pd ensemble size, from single atoms to dimers and trimers, in the one-pot hydrogenation reaction between nitrobenzene and benzaldehyde as our probe reaction. The highest (near unity) selectivity to condensation products was achieved using the catalyst with the lowest Pd content prepared (Pd2Au98/SiO2), which predominantly exposed surface Pd single atoms as verified by surface-sensitive spectroscopy. Theoretical calculations reveal that Pd single atoms were inactive for benzaldehyde adsorption and thus enabled selective nitrobenzene hydrogenation. On the contrary, the adsorption of benzaldehyde became stronger than nitrobenzene for Pd trimers and larger ensembles, explaining the enhanced competitive adsorption from benzaldehyde with increasing Pd content. Our results demonstrate that the commonly used (near equimolar) alloying ratio is rather arbitrary and may not necessarily produce the highest selectivity to condensation products. Instead, we illustrate how nanoscale Pd ensemble size control tunes competitive kinetics to steer selectivity towards forming the desired condensation products.
Timed chromatin invasion during mitosis governs prototype foamy virus integration site selection and infectivity
(Oxford Academic, 2025-05-31) Lagadec, Floriane; Calmels, Christina; Lapaillerie, Delphine; Lindemann, Dirk; Parissi, Vincent; Engelman, Alan N.; Lesbats, Paul; Singh, Parmit; Cherepanov, Peter
Selection of a suitable chromatin environment during retroviral integration is a tightly regulated process. Most retroviruses, including spumaretroviruses, require mitosis for nuclear entry. However, whether intrinsic chromatin dynamics during mitosis modulates retroviral genome invasion is unknown. Previous work uncovered critical interactions of prototype foamy virus (PFV) Gag with nucleosomes via a highly conserved arginine anchor residue. Yet, the regulation of Gag-chromatin interaction and its functional consequences for spumaretrovirus biology remain obscure. Here, we investigated the kinetics of chromatin binding by Gag during mitosis and proviral integration in synchronized cells. We showed that alteration of Gag affinity for nucleosome binding induced untimely chromatin tethering during mitosis, decreased infectivity, and redistributed viral integration sites to markers associated with late replication timing of chromosomes. Mutant Gag proteins were, moreover, defective in their ability to displace the histone H4 tail from the nucleosome acidic patch of highly condensed chromatin. These data indicate that the chromatin landscape during Gag-nucleosome interactions is important for PFV integration site selection and that spumaretroviruses evolved high-affinity chromatin binding to overcome early mitosis chromatin condensation.
Repairing Modern First Edition Dust Jackets Without Fills or Inpainting: A Conservative Approach
(The American Institute for Conservation of Historic and Artistic Works, 2024-05) Sokolowski, Christopher
This poster presents a minimally invasive method for repairing damaged modern first edition dust jackets. The technique uses lightweight kozo tissue precoated with Klucel G (hydroxypropyl cellulose) adhesive and visually fills losses by placing a toned or printed secondary jacket beneath the original. This approach preserves the dust jacket’s authenticity, while allowing it to appear complete from a short viewing distance during exhibition. Depending on curatorial needs, the jacket’s condition can be either visually improved or its wear emphasized.
Developed for a curatorial brief at Harvard’s Houghton Library in early 2023, this reversible strategy was used to reunite and stabilize the dust jacket for E.E. Cummings’s The Enormous Room (1922), enabling its display and subsequent storage with the book. The aim was to create the illusion of completeness without invasive or time-consuming fills, preserving the original material as much as possible.
By sharing this method in the Book and Paper Group Annual, I hope to highlight a conservative yet visually satisfying alternative to the widespread use of in-painting and invasive fills in dust jacket restoration.
Taking Notes on Philosophical Texts
(1999-01-01) Suber, Peter
Repairing Modern First Edition Dust Jackets Without Fills or Inpainting: A Conservative Approach
(The American Institute for Conservation of Historic and Artistic Works, 2024) Sokolowski, Christopher
The dust jacket of a modern first edition—often discarded when new—has become the most historically and commercially valuable component of a book. Despite this elevated status, many important dust jackets undergo extensive cosmetic restoration that is often disproportionate to their rarity and significance.
This article presents a minimally invasive method for repairing damaged modern first edition dust jackets. The technique uses lightweight kozo tissue precoated with Klucel G (hydroxypropylcellulose) adhesive, and visually fills losses by placing a toned or printed secondary jacket beneath the original. This approach preserves the dust jacket’s authenticity, while allowing it to appear complete from a short viewing distance during exhibition. Depending on curatorial needs, the jacket’s condition can be either visually improved or its wear emphasized.
Developed for a curatorial brief at Harvard’s Houghton Library in early 2023, this reversible strategy was used to reunite and stabilize the dust jacket for E.E. Cummings’s The Enormous Room (1922), enabling its display and subsequent storage with the book. The aim was to create the illusion of completeness without invasive or time-consuming fills, preserving the original material as much as possible.
The core of this article is an illustrated, step-by-step review of the Enormous Room treatment, including the rationale for avoiding aqueous techniques. Additional case studies are provided where more extensive compensation of design or text was needed through the secondary jacket. Practical guidelines for sourcing, scaling, and color-correcting digital files to match original jackets are also included.
By sharing this method in the Book and Paper Group Annual, I hope to highlight a conservative yet visually satisfying alternative to the widespread use of in-painting and invasive fills in dust jacket restoration.