Many pathogens, including Plasmodium spp., exploit the interaction of programmed death-1 (PD-1) with PD-1-ligand-1 (PD-L1) to "deactivate" T cell functions, but the role of PD-L2 remains unclear. We studied malarial infections to understand the contribution of PD-L2 to immunity. Here we have shown that higher PD-L2 expression on blood dendritic cells, from Plasmodium falciparum-infected individuals, correlated with lower parasitemia. Mechanistic studies in mice showed that PD-L2 was indispensable for establishing effective CD4(+) T cell immunity against malaria, because it not only inhibited PD-L1 to PD-1 activity but also increased CD3 and inducible co-stimulator (ICOS) expression on T cells. Importantly, administration of soluble multimeric PD-L2 to mice with lethal malaria was sufficient to dramatically improve immunity and survival. These studies show immuno-regulation by PD-L2, which has the potential to be translated into an effective treatment for malaria and other diseases where T cell immunity is ineffective or short-lived due to PD-1-mediated signaling.

Pittosporum eugenioides is a native ornamental species with a wide distribution throughout New Zealand. The effects of the application of two plant hormones (gibberellic acid and ahscisic acid) and a gibberellin biosynthesis inhibitor (paclobutrazol) on the growth and development, frost resistance, and water loss on two-year old seedlings of P. eugenioides were studied. Gibberellic acid increased plant growth, stem diameter, and shoot succulence, while also inducing leaf hyponasty and vegetative bud break of apices. Abscisic acid induced growth suppression while being effective in promoting leaf epinasty and inhibiting bud break. Paclobutrazol induced growth suppression, promoted epinasty, decreased shoot succulence, inhibited bud break in apices, and increased foliar frost resistance. The effects of paclobutrazol were also overcome by the addition of gibberellic acid. The results are compared with those gained from species not native to New Zealand, and indicate the potential for the application of plant growth regulators to a New Zealand species of ornamental value.

A hydrogen-bonded solid has pores sustained by complementary interactions between hexaaqua metal cations and phosphonate anions. The pores are templated by guest molecules of a certain size and chemical functionality, but these guests are removable. Even though the activated form of the solid is 27% water by weight, reversible gas sorption is demonstrated. The framework shows adaptability to different guest species.

Classical force fields within the CHARMM parametrized model are developed for zinc phthalocyanines including the parent per-hydro molecule and per-fluoro-alkyl substituted derivatives. Partial atomic charges, 2-body bond lengths, and 3-body angle parameters were obtained from B3LYP-level density functional calculations. Force constants for 2-, 3-, and 4-body interactions were derived from existing fluoroalkane models and incorporated assuming transferability. The force fields were validated by comparing equilibrium molecular geometries from molecular dynamics simulations with density functional theory (DFT) calculations and, where available, published experimental XRD refinements. The models produce molecular geometries for the target materials within 1-2% of expected values. Intermolecular interaction geometries were also investigated using molecular dynamics simulations. The results provide new insight and predictions of the equilibrium stacking and orientational intermolecular interactions of this novel class of modified phthalocyanines.

For efficient charge separation and charge transport in optoelectronic materials, small internal reorganization energies are desired. While many p-type organic semiconductors have been reported with low internal reorganization energies, few n-type materials with low reorganization energy are known. Metal phthalocyanines have long received extensive research attention in the field of organic device electronics due to their highly tunable electronic properties through modification of the molecular periphery. In this study, density functional theory (DFT) calculations are performed on a series of zinc-phthalocyanines (ZnPc) with various degrees of peripheral per-fluoroalkyl (-C3F7) modification. Introduction of the highly electron withdrawing groups on the periphery leads to a lowering in the energy of the molecular frontier orbitals as well as an increase in the electron affinity. Additionally, all molecules studies are found to be most stable in their anionic form, demonstrating their potential as n-type materials. However, the calculated internal reorganization energy slightly increases as a function of peripheral modification. By varying the degree of modification we develop a strategy for obtaining an optimal balance between low reorganization energy and high electron affinity for the development of novel n-type optoelectronic materials.