Structural and Reactivity Studies of “Pincer” Pyridine Dicarbene Complexes of Fe0: Experimental and Computational Comparison of the Phosphine and NHC Donors

Pincer carbene complexes : Comparison of the electronic structures of “pincer” Fe⁰ pyridine bis(imidazol‐2‐ylidene) and pyridine diphosphine dicarbonyl complexes (see figure) show subtle differences that account for observed spectroscopic trends. Intermolecular C? H activation has been observed in Fe pyridine dicarbene complexes.

     

A new method of assessing the efficiency of second harmonic generation by small samples of organic crystals

The intensity of optical second harmonic generation was measured from pressed KCl disks containing low concentrations (1%) of non-linear optical (NLO) materials. Comparison of the signals at 532 nm, with the known second order NLO coefficients exhibited a monotonic relationship. An estimate was made of the effect of light scattering at 532 nm, on the results.     

Angular correlations in proton-proton collisions producing a high transverse momentum π0

In an experiment at the CERN ISR, a streamer chamber detector surrounding one of the intersection regions was triggered on large transverse momentum π⁰'s by means of an array of lead-glass counters. The directions of charged particles and γ rays converted in lead-oxide plates inside the streamer chamber were measured. Data were taken at c.m. energy of √s = 53 GeV at two production angles of the high p_Tπ⁰ (90° and 53°). They indicate an enhancement of particles mostly in the hemisphere opposite to the π⁰. In the 53° data, a shift of this enhancement towards rapidities opposite to the rapidity of the π⁰ and confined to a ±30° azimuthal region around the collision plane is observed. In addition, a short-range angular correlation is evidenced between the high p_Tπ⁰ and the other collisions products (photons or charged particles). Two-particle correlations between charged particles produced in association with the high p_Tπ⁰ are found similar to those     

General methods of elliptic minimization

We provide general methods in the calculus of variations for the anisotropic Plateau problem in arbitrary dimension and codimension. Given a collection of competing “surfaces” that span a given “bounding set” in an ambient metric space, we produce one minimizing an elliptic area functional. The collection of competing surfaces is assumed to satisfy a set of geometrically-defined axioms. These axioms hold for collections defined using any combination of homological, cohomological or linking number spanning conditions. A variety of minimization problems can be solved, including sliding boundaries.     

Multiformat T‐Cell‐Engaging Bispecific Antibodies Targeting Human Breast Cancers

Four different formats of bispecific antibodies (bsAbs) were generated that consist of anti‐Her2 IgG or Fab site‐specifically conjugated to anti‐CD3 Fab using the genetically encoded noncanonical amino acid. These bsAbs varied in valency or in the presence or absence of an Fc domain. Different valencies did not significantly affect antitumor efficacy, whereas the presence of an Fc domain enhanced cytotoxic activity, but triggered antigen‐independent T‐cell activation. We show that the bsAbs can efficiently redirect T cells to kill all Her2 expressing cancer cells, including Her2 1+ cancers, both in vitro and in rodent xenograft models. This work increases our understanding of the structural features that affect bsAb activity, and underscores the potential of bsAbs as a promising therapeutic option for breast cancer patients with low or heterogeneous Her2 expression.