120 research outputs found

    Researching Market and Supply-Chain Opportunities for Local Foods Systems: Setting Priorities and Identifying Linkages

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    There is an increasing array of land-grant, nonprofit, and other academic programs intended to support the development of food system enterprises and programs. However, research to track consumers\u27 evolving preferences and behaviors within these systems and to measure the intended policy outcomes of any public investments in these systems is lagging. This research commentary represents a compilation of opinions and insights from those who are interested in exploring research priorities for economic, marketing, and supply-chain aspects of local food systems. The priorities that emerge are framed in the following way: (1) opportunities for increased and more targeted research to help identify gaps in the literature; (2) areas where current localized research projects could be leveraged and scaled up to the national level; and (3) innovative projects and partnerships that are evolving to bridge both knowledge and systems gaps

    CVD growth of carbon nanostructures from zirconia: mechanisms and a method for enhancing yield.

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    By excluding metals from synthesis, growth of carbon nanostructures via unreduced oxide nanoparticle catalysts offers wide technological potential. We report new observations of the mechanisms underlying chemical vapor deposition (CVD) growth of fibrous carbon nanostructures from zirconia nanoparticles. Transmission electron microscope (TEM) observation reveals distinct differences in morphological features of carbon nanotubes and nanofibers (CNTs and CNFs) grown from zirconia nanoparticle catalysts versus typical oxide-supported metal nanoparticle catalysts. Nanofibers borne from zirconia lack an observable graphitic cage consistently found with nanotube-bearing metal nanoparticle catalysts. We observe two distinct growth modalities for zirconia: (1) turbostratic CNTs 2-3 times smaller in diameter than the nanoparticle localized at a nanoparticle corner, and (2) nonhollow CNFs with approximately the same diameter as the nanoparticle. Unlike metal nanoparticle catalysts, zirconia-based growth should proceed via surface-bound kinetics, and we propose a growth model where initiation occurs at nanoparticle corners. Utilizing these mechanistic insights, we further demonstrate that preannealing of zirconia nanoparticles with a solid-state amorphous carbon substrate enhances growth yield.This material is based upon work supported by the National Science Foundation under Grant No. 1007793 and was also supported by Airbus group, Boeing, Embraer, Lockheed Martin, Saab AB, Hexcel, and TohoTenax through MIT’s Nano- Engineered Composite aerospace STructures (NECST) Consortium. This research was supported (in part) by the U.S. Army Research Office under Contract W911NF-13-D-0001. This work was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Infrastructure Network (NNIN), which is supported by the National Science Foundation under NSF Award No. ECS-0335765. CNS is part of Harvard University. This work was carried out in part through the use of MIT Microsystems Technology Laboratories. Stephan Hofmann acknowledges funding from EPSRC under grant EP/H047565/1. Piran Kidambi acknowledges the Lindemann Trust Fellowship.This is the final published version. It first appeared at http://pubs.acs.org/doi/abs/10.1021/ja509872y

    Bone marrow-derived cells in ocular neovascularization: contribution and mechanisms

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    Ocular neovascularization often leads to severe vision loss. The role of bone marrow-derived cells (BMCs) in the development of ocular neovascularization, and its significance, is increasingly being recognized. In this review, we discuss their contribution and the potential mechanisms that mediate the effect of BMCs on the progression of ocular neovascularization. The sequence of events by which BMCs participate in ocular neovascularization can be roughly divided into four phases, i.e., mobilization, migration, adhesion and differentiation. This process is delicately regulated and liable to be affected by multiple factors. Cytokines such as vascular endothelial growth factor, granulocyte colony-stimulating factor and erythropoietin are involved in the mobilization of BMCs. Studies have also demonstrated a key role of cytokines such as stromal cell-derived factor-1, tumor necrosis factor-α, as well as vascular endothelial growth factor, in regulating the migration of BMCs. The adhesion of BMCs is mainly regulated by vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and vascular endothelial cadherin. However, the mechanisms regulating the differentiation of BMCs are largely unknown at present. In addition, BMCs secrete cytokines that interact with the microenvironment of ocular neovascularization; their contribution to ocular neovascularization, especially choroidal neovascularization, can be aggravated by several risk factors. An extensive regulatory network is thought to modulate the role of BMCs in the development of ocular neovascularization. A comprehensive understanding of the involved mechanisms will help in the development of novel therapeutic strategies related to BMCs. In this review, we have limited the discussion to the recent progress in this field, especially the research conducted at our laboratory

    Synthesis of Some New 2-Methyl -1,4-benzothiazine-3(1H)- one Derivatives as Potential Vasodilators

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    The increase in the internal diameter of a blood vessel that results from relaxation of smooth muscle within the wall of the vessel is vasodilation. This causes an increase in blood flow and a decrease in systemic vascular resistance. Some substances produced by tissue deprived of fresh blood seem to be responsible for the dilation. Many products of metabolism bring about the action, CO2 and acids are among them. Dilation of vessels is necessary to restore local environment of tissues and normal metabolism. It may prove to be potential in the treatment of different cardiac disorders like atherosclerosis, where, the blood vessels are narrowed due to deposition of plaque of substances like cholesterol etc. 1,4-benzothiazines have been reported to possess wide range of pharmacological and biological activities. Here, we report the synthesis and biological activity of some new arylidenehydrazino-(1H)-1,4-benzothiazines. The synthesized compounds were subjected to a prediction of biological activities. A software application (PASS) was used for this purpose. The relationship between structure and different biological activities was studied and it was found that the arylidenehydrazino-(1H)-1,4-benzothiazines are expected to be potential vasodilators

    Synthesis and study of biological activity of some new 1,4-benzothiazines

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    852-859N-(4-methylpyrimidin-2-one-4-yl)-1,4-benzothiazine-2,3-dione 5, 2-thio-2,6-dimethyl[1,3,5]triazino[3,4-c]-1,4-benzothiazine 9, [1,2,4]-triazino-2-oxo-[3,4-c][1,4]-benzothiazine 13, 5-arylidene-1H-1,4-benzothiazine[1,3,4]triazole 16a-b, 2-thio-6-methyl[1,3,5]triazino[3,4-c]benzothiazine 19, N-(2-propanoyl)-1,4-benzothiazne-3(1H)-one 20, tricyclic compound cyclopenteno-1,4-benzothiazine 21 have been synthesized and characterized by spectral data
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