The parametrization and testing of the OPLS all-atom force field for organic molecules and peptides are described. Parameters for both torsional and nonbonded energetics have been derived, while the bond stretching and angle bending parameters have been adopted mostly from the AMBER all-atom force field. The torsional parameters were determined by fitting to rotational energy profiles obtained from ab initio molecular orbital calculations at the RHF/6-31G*//RHF/6-31G* level for more than 50 organic molecules and ions. The quality of the fits was high with average errors for conformational energies of less than 0.2 kcal/mol. The force-field results for molecular structures are also demonstrated to closely match the ab initio predictions. The nonbonded parameters were developed in conjunction with Monte Carlo statistical mechanics simulations by computing thermodynamic and structural properties for 34 pure organic liquids including alkanes, alkenes, alcohols, ethers, acetals, thiols, sulfides, disulfides, aldehydes, ketones, and amides. Average errors in comparison with experimental data are 2% for heats of vaporization and densities. The Monte Carlo simulations included sampling all internal and intermolecular degrees of freedom. It is found that such non-polar and monofunctional systems do not show significant condensed-phase effects on internal energies in going from the gas phase to the pure liquids.

The AACR Project GENIE is an international data-sharing consortium focused on generating an evidence base for precision cancer medicine by integrating clinical-grade cancer genomic data with clinical outcome data for tens of thousands of cancer patients treated at multiple institutions worldwide. In conjunction with the first public data release from approximately 19,000 samples, we describe the goals, structure, and data standards of the consortium and report conclusions from high-level analysis of the initial phase of genomic data. We also provide examples of the clinical utility of GENIE data, such as an estimate of clinical actionability across multiple cancer types (>30%) and prediction of accrual rates to the NCI-MATCH trial that accurately reflect recently reported actual match rates. The GENIE database is expected to grow to >100,000 samples within 5 years and should serve as a powerful tool for precision cancer medicine. Significance The AACR Project GENIE aims to catalyze sharing of integrated genomic and clinical datasets across multiple institutions worldwide, and thereby enable precision cancer medicine research, including the identification of novel therapeutic targets, design of biomarker-driven clinical trials, and identification of genomic determinants of response to therapy.

Absorption and photoluminescence properties of terrylene derivative 7,8,15,16-tetraazaterrylene (TAT) in its solution and crystal phases have revealed rather unusual spectral characteristics that defy classification in terms of simple H-or J-aggregatecoupled systems. TAT readily forms crystalline aggregates by either self-assembly in solution or physical vapor deposition, based on π stacks aligned roughly along the crystallographic a axis. Using a Holstein-style Hamiltonian including both Frenkel and chargetransfer (CT) excitons, the crystal absorption and steady-state photoluminescence (PL) spectra/line shapes are shown to be determined by a competition between long-range Coulombic coupling, which induces H-aggregate behavior, and short-range charge-transfer-mediated coupling, which induces J-like behavior. Such "HJ" aggregates display J-aggregate signatures in the low-energy region of the absorption spectrum and H-aggregate signatures at higher energies, which are in excellent agreement with our experiments. The H/J competition also results in a sharp reduction in the exciton bandwidth and the appearance of an exciton band minima at k ≈ ±π/2, where k is the dimensionless wave vector along the stacking axis. The presence of a band minimum for nonzero values of k bestows hybrid HJ behavior in the PL spectrum. We present a new design paradigm for organic electronic materials on the basis of the constructive or destructive interference of short-and long-range coupling, postulating the existence of HH, JJ, JH, and HJ aggregates with unique transport and radiative properties.

A s part of a larger study of the development of postnatal rat cerebral cortex, this report deals with the maturation of the cortex as a tissue from birth to twenty-one days of age. The changes in the numerical density of cells and blood vessels and the thickness of the cortex at successive ages were followed on light micrographs, and both were related to the ultrastructural observations on routine electron microscopic preparations. The maturation of the cortex is divided into two periods: The first ten days during which the growth to adult dimensions occurs and few patent blood vessels but large extracellular spaces are to be found, and the second ten days in which the majority of the vessels develop patent lumina, the perivascular sheath of astrocyte end-feet develops, and the large extracellular spaces disappear concomitant with the maturation of the neuropil.The blood vessels appear to develop during the first ten days as solid cords of mesodermal elements which form a network of primordial vessels with thick walls and slit-like lumina containing a flocculent material. The formation of a blood filled, patent lumen apparently occurs synchronously over a brief period of time for the majority of the vessels during the early part of the second ten-day period. The basal lamina is ill-defined initially but takes on mature appearance parallel with the development of the pcrivascular glial sheath.The volume of the extracellular space was found to be largest during the phase of rapid growth of axons and dendrites when few patent vessels exist. The disappearance of these large extracellular spaces during maturation of the blood vessels and neuropil is discussed i n terms of the possible artifactitious nature of these spaces in both immature and mature cortex.

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