693 research outputs found
Gold Coated Tungsten Tips for Scanning Tunneling Microscopy
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Review of Scientific Instruments and may be found at https://doi.org/10.1063/1.1144069.Electrochemically etched tungsten scanning tunneling microscope (STM) tips are dc sputter coated with 20 nm of gold (0.04 rim/s and 10 mTorr of argon). Transmission electron microscope (TEM) images of typical etched tips and gold-coated etched tips are presented. The gold layer forms as a series of spherical sections having a mean height of 6.7 nm and mean width of 19.6 nm. STM images are reported for the uncoated W tips, and for gold-coated graphite after coating the tip with gold. We also provide scanning electron microscopy (SEM) and STM images of the surface of a thin CuTCNQ film. The STM image taken with a gold-coated W tip compares very well to the SEM image of the same sample. Gold coating provides a relatively inexpensive and easy way to produce chemically stable tips of well known electronic structure for use in ambient atmosphere STM studies of morphology (structures ) 10 nm) where atomic resolution is not required.G.A. Fried, X.D. Wang, and K.W. Hipps. (1993). Gold Coated Tungsten Tips for Scanning Tunneling Microscopy. Review of Scientific Instruments. 64. 1495-1501
Model-based optimisation of sustainable biological nutrient removal processes
No full textApplied Science
Erratum: Keating et al. (2017)
No full textIn the article by Keating, X.D., Zhou, K., Liu, J., Shangguan, R., Fan, Y., and Harrison, L., “Research on Preservice Physical Education Teachers’ and Preservice Elementary Teachers’ Physical Education Identities: A Systematic Review,” in Journal of Teaching in Physical Education, 36, 2, https://doi.org/10.1123/jtpe.2016-0128, the author order was incorrectly listed. The online version of this article has been corrected.</jats:p
A road map for constructive collaboration among stakeholders: An improvement to stakeholder participation in virtual design and construction engineering design projects
No full textCivil Engineering and GeosciencesStructural EngineeringConstruction Management and Engineerin
Aberration analysis of Wien filters and design of an electron energy-selective imaging system
No full textNatural and anthropogenic forest fires recorded in the Holocene pollen record from a Jinchuan peat bog, northeastern China
No full textPollen and charcoal particles from a Jinchuan peat (northeastern China) were examined to investigate the fire origin and interaction between
climate, vegetation, fire and human activity during the Holocene. Pollen results show that: (i) a broadleaved deciduous forest was dominant during
the early Holocene; (ii) from ~5500 cal. yr B.P. there was a gradual increase in coniferous trees (mainly Pinus), and a decrease in broadleaved
deciduous trees (e.g. Quercus, Juglans, and Ulmus–Zelkova); (iii) after ~4200 cal. yr B.P., the deciduous forest was replaced by a mixed forest of
coniferous and deciduous trees; (iv) coniferous trees including Pinus, Abies and Picea further increased after ~2000 cal. yr B.P., reflecting a
cooler and drier climate after ~5500–4200 cal. yr B.P. Two layers of abundant microfossil charcoal particles (250–10 μm) and the coexistence of
macrofossil particles (N2 mm) suggest two local fires: fire event 1 (5120±66 cal. yr B.P.) and fire event 2 (1288±8 cal. yr B.P., AD 662±8).
Charcoal layer 1, with a large amount of Monolete psilate spores, is superimposed on the long-term trend of vegetation changes, indicating a
natural origin for fire event 1 that was probably facilitated by drying environmental conditions since the mid-Holocene. Cerealia-type pollen and a
low percentage of Monolete psilate spores were observed in charcoal layer 2, indicating that fire event 2 was caused by clearing. We suggest that
fire event 2 may be related to the spread of the Han farming culture accompanied by the territorial expansion of the Tang Dynasty to the studied
area in AD 668
Integrated Omics Reveals the Orchestrating Role of Calycosin in Danggui Buxue Tang, a Herbal Formula Containing Angelicae Sinensis Radix and Astragali Radix, in Inducing Osteoblastic Differentiation and Proliferation
No full textSystems biology unravels the black box of signaling pathway of cells; but which has not been extensively applied to reveal the mechanistic synergy of a herbal formula. The therapeutic efficacies of a herbal formula having multi-target, multi-function and multi-pathway are the niches of traditional Chinese medicine (TCM). Here, we reported an integrated omics approach, coupled with the knockout of an active compound, to measure the regulation of cellular signaling, as to reveal the landscape in cultured rat osteoblasts having synergistic pharmacological efficacy of Danggui Buxue Tang (DBT), a Chinese herbal formula containing Angelicae Sinensis Radix and Astragali Radix. The changes in signaling pathways responsible for energy metabolism, RNA metabolism and protein metabolism showed distinct features between DBT and calycosin-depleted DBT. Here, our results show that calycosin within DBT can orchestrate the osteoblastic functions and signaling pathways of the entire herbal formula. This finding reveals the harmony of herbal medicine in pharmacological functions, as well as the design of drug/herbal medicine formulation. The integration of systems biology can provide novel and essential insights into the synergistic property of a herbal formula, which is a key in modernizing TCM.</p
Specific factors meet intermediate inputs : implications for strategic complementarities and persistence
No full textA central challenge to monetary business-cycle theory is to find a solution to the problem of persistence and delay in the real effects of monetary shocks. Previous research has identified separately specific factors and intermediate inputs as two promising mechanisms for generating the persistence and delay in a staggered price-setting framework. Models based on either of these two mechanisms have also been used in the design of optimal monetary policy. ; By examining a staggered price model that features both specific factors and intermediate inputs, the author finds an offsetting interaction between the two individually promising mechanisms, which leads to a cancellation of much of the impact of each in propagating monetary shocks. This finding posits a challenge to the search for a robust monetary transmission mechanism and design of optimal monetary policy.Monetary theory
The osteogenic function of danggui buxue tang, a herbal decoction containing astragali radix and angelicae sinensis radix, is optimized by boiling the two herbs together: Signaling analyses revealed by systems biology
No full textThe therapeutic efficacy of a herbal mixture, being multi-target, multi-function and multi-pathway, is the niche of traditional Chinese medicine (TCM). Systems biology can dissect the network of signaling mechanisms in a complex biological system. In preparing TCM decoctions, the boiling of herbs together in water is a common practice; however, the rationale of this specific preparation has not been fully revealed. An approach of mass-spectrometry-based multi-omics was employed to examine the profiles of the cellular pathways, so as to understand the pharmacological efficacy of Danggui Buxue Tang (DBT), a Chinese herbal mixture containing Astragali Radix and Angelicae Sinensis Radix, in cultured rat osteoblasts and mesenchymal stem cells. The results, generated from omics analyses, were compared from DBT-treated osteoblasts to those of treating the herbal extract by simple mixing of extracts from Astragali Radix and Angelicae Sinensis Radix, i.e., herbal mixture without boiling together. The signaling pathways responsible for energy metabolism and amino acid metabolism showed distinct activation, as triggered by DBT, in contrast to simple mixing of two herbal extracts. The result supports that boiling the herbs together is designed to maximize the osteoblastic function of DBT, such as in energy and lipid metabolism. This harmony of TCM formulation, by having interactive functions of two herbs during preparation, is being illustrated. The systems biology approach provides new and essential insights into the synergy of herbal preparation. Well-defined multiple targets and multiple pathways in different levels of omics are the key to modernizing TCM.</p
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