There are significant challenges in developing deformable devices at the system level that contain integrated, deformable energy storage devices. Here we demonstrate an origami lithium-ion battery that can be deformed at an unprecedented high level, including folding, bending and twisting. Deformability at the system level is enabled using rigid origami, which prescribes a crease pattern such that the materials making the origami pattern do not experience large strain. The origami battery is fabricated through slurry coating of electrodes onto paper current collectors and packaging in standard materials, followed by folding using the Miura pattern. The resulting origami battery achieves significant linear and areal deformability, large twistability and bendability. The strategy described here represents the fusion of the art of origami, materials science and functional energy storage devices, and could provide a paradigm shift for architecture and design of flexible and curvilinear electronics with exceptional mechanical characteristics and functionalities.

The serendipitously discovered solution-liquid-solid (SLS) mechanism has been refined into a nearly general synthetic method for semiconductor nanowires. Purposeful control of diameters and diameter distributions is achieved. The synthesis proceeds by a solution-based catalyzed-growth mechanism in which nanometer-scale metallic droplets catalyze the decomposition of metallo-organic precursors and crystalline nanowire growth. Related growth methods proceeding by the analogous vapor-liquid-solid (VLS) and supercritical fluid-liquid-solid (SFLS) mechanisms are known, and the relative attributes of the methods are compared. In short, the VLS method is most general and appears to afford nanowires of the best crystalline quality. The SLS method appears to be advantageous for producing the smallest nanowire diameters and for variation and control of surface ligation. The SFLS method may represent an ideal compromise. Recent results for SLS growth are summarized.

Tri-n-octylphosphine oxide (TOPO) is a commonly used solvent for nanocrystal synthesis. Commercial TOPO samples contain varying amounts of phosphorus-containing impurities, some of which significantly influence nanocrystal growth. Consequently, nanocrystal syntheses often give irreproducible results with different batches of TOPO solvent. In this study, we identify TOPO impurities by (31)P NMR, and correlate their presence with the outcomes of CdSe nanocrystal syntheses. We subsequently add the active impurity species, one by one, to purified TOPO to confirm their influence on nanocrystal syntheses. In this manner, di-n-octylphosphine oxide (DOPO) is shown to assist CdSe quantum-dot growth; di-n-octylphosphinic acid (DOPA) and mono-n-octylphosphinic acid (MOPA) are shown to assist CdSe quantum-rod growth, and DOPA is shown to assist CdSe quantum-wire growth. (The TOPO impurity n-octylphosphonic acid, OPA, has been previously shown to assist quantum-rod growth.) The beneficial impurities are prepared on multigram scales and can be added to recrystallized TOPO to provide reproducible synthetic results.

Tri-n-octylphosphine oxide (TOPO) is the most commonly used solvent for the synthesis of colloidal nanocrystals. Here we show that the use of different batches of commercially obtained TOPO solvent introduces significant variability into the outcomes of CdSe quantum-wire syntheses. This irreproducibility is attributed to varying amounts of phosphorus-containing impurities in the different TOPO batches. We employ 31P NMR to identify 10 of the common TOPO impurities. Their beneficial, harmful, or negligible effects on quantum-wire growth are determined. The impurity di-n-octylphosphinic acid (DOPA) is found to be the important beneficial TOPO impurity for the reproducible growth of high-quality CdSe quantum wires. DOPA is shown to beneficially modify precursor reactivity through ligand substitution. The other significant TOPO impurities are ranked according to their abilities to similarly influence precursor reactivity. The results are likely of general relevance to most nanocrystal syntheses conducted in TOPO.

By using a combination of genetic, pharmacological, and anatomical approaches, we show that the melanocortin 4 receptor (MC4R), implicated in the control of food intake and energy expenditure, also modulates erectile function and sexual behavior. Evidence supporting this notion is based on several findings: (i) a highly selective nonpeptide MC4R agonist augments erectile activity initiated by electrical stimulation of the cavernous nerve in wild-type but not Mc4r-null mice; (ii) copulatory behavior is enhanced by administration of a selective MC4R agonist and is diminished in mice lacking Mc4r; (iii) reverse transcription (RT)-PCR and non-PCR based methods demonstrate MC4R expression in rat and human penis, and rat spinal cord, hypothalamus, brainstem, pelvic ganglion (major autonomic relay center to the penis), but not in rat primary corpus smooth muscle cavernosum cells; and (iv) in situ hybridization of glans tissue from the human and rat penis reveal MC4R expression in nerve fibers and mechanoreceptors in the glans of the penis. Collectively, these data implicate the MC4R in the modulation of penile erectile function and provide evidence that MC4R-mediated proerectile responses may be activated through neuronal circuitry in spinal cord erectile centers and somatosensory afferent nerve terminals of the penis. Our results provide a basis for the existence of MC4R-controlled neuronal pathways that control sexual function.O ur understanding of the physiology and anatomy of erectile function has advanced considerably in recent years (1-4). Penile erection is a highly coordinated reflex that is subject to modulation at many levels of the neuraxis. Relaxation of smooth muscle fibers of erectile tissue and concomitant dilatation of the arterial supply in the penis produce penile erection. Activation of neurons in the sacral spinal cord triggers activity in the pelvic nerve and, subsequently, the cavernous nerve, which can lead to the release of mediators of vasorelaxation, including nitric oxide. These mediators modulate cyclic nucleotide levels resulting in Ca 2ϩ sequestration and relaxation of smooth muscle fibers of the corpora cavernosa and corpus spongiosum in the shaft of the penis to produce arterial dilatation, engorgement of the penis with blood, and tumescence. Erections can be triggered either by peripheral (tactile) or by central (visual, olfactory, auditory, or imaginative cues) activation of somatic pathways and, as such, are influenced by tonic and phasic activity in the lumbosacral spinal cord and the brain.Five melanocortin heterotrimeric GTP-binding protein (G protein)-coupled receptors have been identified as expressed in different tissues (5, 6). The functional role of each of these five melanocortin receptors is being defined. Rodent and human genetic and pharmacological evidence indicates that activation of melanocortin 4 receptor (MC4R) results in a lean phenotype, whereas inactivation of the MC4R results in obesity (7-10). Recent studies have demonstrated that MTII, a cyclic analogue of ␣-mel...