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Journal ArticleDOI

Possibilities and Limitations

01 May 1970-Problems of Economic Transition (Routledge)-Vol. 13, Iss: 1, pp 21-25
TL;DR: The editors have received a number of comments on V. Kollontai's article on planning problems in the developing countries (see 1969, No. 7) as discussed by the authors, including from G. Smirnov (African Institute), L. Artsishevskii (Economics Institute of the USSR Gosplan), and I. Aleshina (Leningrad University).
Abstract: The editors have received a number of comments on V. Kollontai's article on planning problems in the developing countries (see 1969, No. 7). In this issue, we hear from G. Smirnov (African Institute), L. Artsishevskii (Economics Institute of the USSR Gosplan), and I. Aleshina (Leningrad University). Other responses reaching the editors will be published in subsequent issues.
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Journal ArticleDOI
TL;DR: This Review discusses the recent progress from the viewpoint of theory and computations, with connections to relevant experiments in the understanding of the molecular structure of the gold-sulfur interface in these systems.
Abstract: Thiolate-protected gold surfaces and interfaces, relevant for self-assembled monolayers of organic molecules on gold, for passivated gold nanoclusters and for molecule-gold junctions, are archetypal systems in various fields of current nanoscience research, materials science, inorganic chemistry and surface science. Understanding this interface at the nanometre scale is essential for a wide range of potential applications for site-specific bioconjugate labelling and sensing, drug delivery and medical therapy, functionalization of gold surfaces for sensing, molecular recognition and molecular electronics, and gold nanoparticle catalysis. During the past five years, considerable experimental and theoretical advances have furthered our understanding of the molecular structure of the gold-sulfur interface in these systems. This Review discusses the recent progress from the viewpoint of theory and computations, with connections to relevant experiments.

1,408 citations


Cites background from "Possibilities and Limitations"

  • ...a–c, Atomic structure of cysteine pairs on Au(110)...

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  • ...STM has shown ordering of homochiral (ll or dd) pairs of cysteine on Au(110) on adsorption from a racemic mixture, and the concomitant DFT calculations implied that the pairing is assisted by reorganization of Au atoms at the surface (Fig....

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  • ...STM experiments and DFT calculations have validated this model to some extent for adsorption of cysteine at an achiral Au(110) surface86....

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Journal ArticleDOI
TL;DR: This work is able to advance a soft electronic fish with a fully integrated onboard system for power and remote control, driven solely by a soft electroactive structure made of dielectric elastomer and ionically conductive hydrogel.
Abstract: Soft robots driven by stimuli-responsive materials have unique advantages over conventional rigid robots, especially in their high adaptability for field exploration and seamless interaction with humans. The grand challenge lies in achieving self-powered soft robots with high mobility, environmental tolerance, and long endurance. We are able to advance a soft electronic fish with a fully integrated onboard system for power and remote control. Without any motor, the fish is driven solely by a soft electroactive structure made of dielectric elastomer and ionically conductive hydrogel. The electronic fish can swim at a speed of 6.4 cm/s (0.69 body length per second), which is much faster than previously reported untethered soft robotic fish driven by soft responsive materials. The fish shows consistent performance in a wide temperature range and permits stealth sailing due to its nearly transparent nature. Furthermore, the fish is robust, as it uses the surrounding water as the electric ground and can operate for 3 hours with one single charge. The design principle can be potentially extended to a variety of flexible devices and soft robots.

572 citations


Cites background from "Possibilities and Limitations"

  • ...Typical stimuli-responsive actuators include ionic polymer metal composites (IPMCs) (21, 22), dielectric elastomers (DEs) (23–26), shape memory alloys (SMAs) (10), responsive hydrogels (27, 28), pneumatic structures (13), chemical reaction– inflated fluidic networks (20), and living cells (14, 15)....

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Journal ArticleDOI
TL;DR: In this article, a 3D macroporous nanoelectronic scaffolds (nanoES) was used for 3D culture of neurons, cardiomyocytes and smooth muscle cells.
Abstract: The development of three-dimensional (3D) synthetic biomaterials as structural and bioactive scaffolds is central to fields ranging from cellular biophysics to regenerative medicine. As of yet, these scaffolds cannot electrically probe the physicochemical and biological microenvironments throughout their 3D and macroporous interior, although this capability could have a marked impact in both electronics and biomaterials. Here, we address this challenge using macroporous, flexible and free-standing nanowire nanoelectronic scaffolds (nanoES), and their hybrids with synthetic or natural biomaterials. 3D macroporous nanoES mimic the structure of natural tissue scaffolds, and they were formed by self-organization of coplanar reticular networks with built-in strain and by manipulation of 2D mesh matrices. NanoES exhibited robust electronic properties and have been used alone or combined with other biomaterials as biocompatible extracellular scaffolds for 3D culture of neurons, cardiomyocytes and smooth muscle cells. Furthermore, we show the integrated sensory capability of the nanoES by real-time monitoring of the local electrical activity within 3D nanoES/cardiomyocyte constructs, the response of 3D-nanoES-based neural and cardiac tissue models to drugs, and distinct pH changes inside and outside tubular vascular smooth muscle constructs.

560 citations

Journal ArticleDOI
01 Jul 2018-Nature
TL;DR: This ptychographic reconstruction improves the image contrast of single-atom defects in MoS2 substantially, reaching an information limit close to 5α, which corresponds to an Abbe diffraction-limited resolution of 0.39 ångström.
Abstract: Aberration-corrected optics have made electron microscopy at atomic resolution a widespread and often essential tool for characterizing nanoscale structures. Image resolution has traditionally been improved by increasing the numerical aperture of the lens (α) and the beam energy, with the state-of-the-art at 300 kiloelectronvolts just entering the deep sub-angstrom (that is, less than 0.5 angstrom) regime. Two-dimensional (2D) materials are imaged at lower beam energies to avoid displacement damage from large momenta transfers, limiting spatial resolution to about 1 angstrom. Here, by combining an electron microscope pixel-array detector with the dynamic range necessary to record the complete distribution of transmitted electrons and full-field ptychography to recover phase information from the full phase space, we increase the spatial resolution well beyond the traditional numerical-aperture-limited resolution. At a beam energy of 80 kiloelectronvolts, our ptychographic reconstruction improves the image contrast of single-atom defects in MoS2 substantially, reaching an information limit close to 5α, which corresponds to an Abbe diffraction-limited resolution of 0.39 angstrom, at the electron dose and imaging conditions for which conventional imaging methods reach only 0.98 angstrom.

441 citations

Journal ArticleDOI
TL;DR: IL-4 therapy can induce Th2 differentiation in human CD4+ T cells and has promise as a potential treatment for psoriasis, a prototypic Th1-associated autoimmune disease.
Abstract: Selective skewing of autoreactive interferon-gamma (IFN-gamma)-producing T helper cells (Th1) toward an interleukin-4 (IL-4)-producing (Th2) phenotype can in experimental animals alleviate autoimmune disease without inducing general immunosuppression. In a prospective dose escalation study, we assessed treatment with human IL-4 (rhuIL-4) in 20 patients with severe psoriasis. The therapy was well tolerated, and within six weeks all patients showed decreased clinical scores and 15 improved more than 68%. Stable reduction of clinical scores was significantly better at 0.2-0.5 microg rhuIL-4 than at < or =0.1 microg rhuIL-4 (P = 0.009). In psoriatic lesions, treatment with 0.2-0.5 microg/kg rhuIL-4 reduced the concentrations of IL-8 and IL-19, two cytokines directly involved in psoriasis; the number of chemokine receptor CCR5+ Th1 cells; and the IFN-gamma/IL-4 ratio. In the circulation, 0.2-0.5 microg/kg rhuIL-4 increased the number of IL-4+CD4+ T cells two- to three-fold. Thus, IL-4 therapy can induce Th2 differentiation in human CD4+ T cells and has promise as a potential treatment for psoriasis, a prototypic Th1-associated autoimmune disease.

429 citations