Our findings illustrate the importance of PLCzeta during fertilization and suggest that mutant forms of PLCzeta may underlie certain types of human male infertility.

Organic bulk‐heterojunction solar cells are being developed as a low‐cost alternative to inorganic photovoltaics. A key step to producing high‐efficiency bulk‐heterojunction devices is film curing using either heat or a solvent atmosphere. All of the literature examining the curing process have assumed that improvement of the bulk‐heterojunction morphology is the reason for the increased filling factor, short‐circuit current density, and efficiency following heat or solvent treatment. We show in this article that heat treatment causes the donor polymer (P3HT) and polymer electrode (PEDOT:PSS) to mix physically to form an interface layer. This interface layer is composed of a mixture of P3HT and PSS in which the P3HT is oxidized to P3HT+. This mixed layer affects the open‐circuit voltage and compensation voltage by limiting the dark current. This result implies that a simplistic description of the P3HT/PEDOT:PSS contact as a sharp interface between bulk P3HT and bulk PEDOT:PSS cannot adequately capture its electrical characteristics.

We report design strategies for the preparation of highly luminescent Au(SG) clusters, where SG is glutathione, by the functionalization of the cluster shell. In these strategies, the cluster shell was covalently modified with small aromatic molecules and pyrene chromophores that led to a 5-fold PL enhancement by rigidifying the shell-gold. Highly luminescent water-soluble gold clusters with a PL quantum yield of 30% were obtained at room temperature. To further enhance the luminescence, the pyrene chromophores in the functionalized Au clusters were photoexcited at 350 nm to induce energy transfer from pyrene to the Au cluster. Steady-state and time-resolved PL measurements have shown evidence of enhanced rigidity with increased PL lifetimes for the functionalized Au clusters. However, the energy transfer efficiency was found to be only 14% because of the competing electron transfer deactivation pathway as evidenced by the formation of the pyrene anion radical revealed in the ultrafast transient absorption measurements. To suppress the electron transfer pathway, the pyrene functionalized Au clusters were ion-paired with tetraoctylammonium (TOA) cations that could break the electron transfer pathway, leading to a dramatic 37-fold increase in PL brightness with the resonance energy transfer efficiency of ca. 80%. This work presents effective design strategies for the preparation of highly luminescent gold clusters by the combination of rigidifying effect and energy transfer sensitization.

Phospholipase Czeta (PLCzeta) is a sperm-specific PLC capable of causing repetitive intracellular Ca2+ ([Ca2+]i) release ([Ca2+]i oscillations) in mammalian eggs. Accumulating evidence suggests that PLCzeta is the sperm factor responsible for inducing egg activation. Nevertheless, some sperm fractions devoid of 72-kDa PLCzeta showed [Ca2+]i oscillation-inducing and PLCzeta-like PLC activity (Kurokawa et al., (2005) Dev. Biol. 285, 376-392). Here, we report that PLCzeta remains functional after proteolytic cleavage at the X-Y linker region. We found that N-terminal (33 and 37 kDa) and C-terminal fragments (27 kDa), presumably the result of PLCzeta cleavage at the X-Y linker region, were present in fresh sperm as well as in sperm extracts and remained associated as functional complexes. Protease V8 cleaved 72-kDa PLCzeta into 33/37 and 27 kDa fragments, while PLC activity and [Ca2+]i oscillation-inducing activity persisted until degradation of the fragments. Immunodepletion or affinity depletion of these fragments abolished PLC activity and [Ca2+]i oscillation-inducing activity from sperm extracts. Lastly, co-expression of cRNAs encoding residues 1-361 and 362-647 of mouse PLCzeta, mimicking cleavage at the X-Y linker region, induced [Ca2+]i oscillations and embryo development in mouse eggs. Our results support the hypothesis that PLCzeta is the sole mammalian sperm factor and that its linker region may have important regulatory functions during mammalian fertilization.

We report on the development of a liquid crystalline block copolymer with brush-type architecture as a platform for creating functional materials by magnetic-fielddirected self-assembly. Ring-opening metathesis of n-alkyloxy cyanobiphenyl and polylactide (PLA) functionalized norbornene monomers provides efficient polymerization yielding low polydispersity block copolymers. The mesogenic species, spacer length, monomer functionality, brush-chain length, and overall molecular weight were chosen and optimized to produce hexagonally packed cylindrical PLA domains which self-assemble and align parallel to an applied magnetic field. The PLA domains can be selectively removed by hydrolytic degradation resulting in the production of nanoporous films. The polymers described here provide a versatile platform for scalable fabrication of aligned nanoporous materials and other functional materials based on such templates.