Publications by authors named "Marcel Langer"

Soft matter integration of photosensitizers and catalysts provides promising solutions to developing sustainable materials for energy conversion. Particularly, hydrogels bring unique benefits, such as spatial control and 3D-accessibility of molecular units, as well as recyclability. Herein, the preparation of polyampholyte hydrogels based on poly(dehydroalanine) (PDha) is reported.

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Machine-learning potentials provide computationally efficient and accurate approximations of the Born-Oppenheimer potential energy surface. This potential determines many materials properties and simulation techniques usually require its gradients, in particular forces and stress for molecular dynamics, and heat flux for thermal transport properties. Recently developed potentials feature high body order and can include equivariant semi-local interactions through message-passing mechanisms.

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Thiomolybdates are molecular molybdenum-sulfide clusters formed from Mo centers and sulfur-based ligands. For decades, they have attracted the interest of synthetic chemists due to their unique structures and their relevance in biological systems, e.g.

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Heterogeneous light-driven catalysis is a cornerstone of sustainable energy conversion. Most catalytic studies focus on bulk analyses of the hydrogen and oxygen evolved, which impede the correlation of matrix heterogeneities, molecular features, and bulk reactivity. Here, we report studies of a heterogenized catalyst/photosensitizer system using a polyoxometalate water oxidation catalyst and a model, molecular photosensitizer that were co-immobilized within a nanoporous block copolymer membrane.

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We introduce the bioconjugation of polymers synthesized by RAFT polymerization, bearing no specific functional end group, by means of hetero-Diels-Alder cycloaddition through their inherent terminal thiocarbonylthio moiety with a diene-modified model protein. Quantitative conjugation occurs over the course of a few hours, at ambient temperature and neutral pH, and in the absence of any catalyst. Our technology platform affords thermoresponsive bioconjugates, whose aggregation is solely controlled by the polymer chains.

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A dual functional chain transfer agent (CTA) capable of highly efficient sequential thermal and photoinduced ligation, generating α,ω-functional polymers, is introduced. The newly designed CTA (1-(4-((2-formyl-3-methyl phenoxy)methyl)phenyl)ethyl (diethoxyphosphoryl)methane dithioate) fuses thermally triggered hetero Diels-Alder chemistry with rapid light-induced photoenol chemistry. The versatility of the CTA is exemplarily demonstrated via the preparation of an amphiphilic triblock quaterpolymer poly(isoprene--styrene)--poly(ethyl acrylate)--poly(ethylene oxide) (P(I--S)--PEA--PEO).

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Micropatterns of hydrophilic polymer brushes were prepared by micromolding in capillaries (MIMIC). The polymers are covalently bound to the surfaces by a rapid hetero Diels-Alder reaction, constituting the first example of polymers grafted to surfaces in a defined pattern by MIMIC. The polymers [poly(acrylic acid), poly(hydroxyethyl acrylate), and poly(tetraethylene glycol acrylate) ranging in molecular weight from 1500 to 6000 g mol(-1)] were prepared with narrow dispersities via the reversible addition-fragmentation chain transfer (RAFT) process using a highly electron deficient RAFT agent that can react with surface-anchored dienes such as cyclopentadiene.

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Objective: To study the immediate and late results obtained from the implantation of vena cava filters in cancer patients with deep vein thrombosis concomitant with neoplasia.

Methods: This was a retrospective evaluation of 50 patients with an association of cancer and deep venous thrombosis who underwent interruption of the inferior vena cava and the insertion of permanent vena cava filters. The indications for the procedure, filter implantation technique, early and late complications related to the operation, and the clinical evolution were evaluated.

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Context: Totally implantable devices are increasingly being utilized for chemotherapy treatment of oncological patients, although few studies have been done in our environment to analyze the results obtained from the implantation and utilization of such catheters.

Objective: To study the results obtained from the implantation of totally implantable catheters in patients submitted to chemotherapy.

Type Of Study: Prospective.

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