Recent developments in the synthetic chemistry of technetium disulfide

2013 ◽  
Vol 42 (44) ◽  
pp. 15540 ◽  
Author(s):  
Maryline Ferrier ◽  
William M. Kerlin ◽  
Frederic Poineau ◽  
Alfred P. Sattelberger ◽  
Kenneth R. Czerwinski
Keyword(s):  
Synthetic Chemistry ◽  
Recent Developments

Choice of biocatalyst form for scalable processes

2006 ◽  
Vol 34 (2) ◽  
pp. 301-303 ◽  
Author(s):  
J.M. Woodley
Keyword(s):  
Protein Engineering ◽  
Process Engineering ◽  
Synthetic Chemistry ◽  
Whole Cell ◽  
Recent Developments

The design of biocatalytic processes for industrial synthetic chemistry is determined in large part by the choice of isolated enzyme or whole-cell catalyst form. In the present paper, the considerations for choice are identified and some important classes of bioconversion are discussed in relation to the choice to be made. Recent developments in cell and protein engineering as well as reactor and process engineering are discussed in addition.

Recent progress in the synthesis of polymers based on carbon dioxide

2006 ◽  
Vol 78 (10) ◽  
pp. 1823-1834 ◽  
Author(s):  
Hiroshi Sugimoto ◽  
Shohei Inoue
Keyword(s):  
Carbon Dioxide ◽  
Transition Metal ◽  
Metal Complexes ◽  
Rational Design ◽  
Recent Progress ◽  
Raw Material ◽  
Synthetic Chemistry ◽  
Recent Developments ◽  
Alternating Copolymerization

The alternating copolymerization of carbon dioxide and epoxide to give polycarbonate has attracted the attention of many chemists, because it is one of the most promising methodologies for the utilization of carbon dioxide as a safe, clean, and abundant raw material in the synthetic chemistry. Recent developments of the catalysts for the alternating copolymerization are based on the rational design of metal complexes, especially complexes of transition metal with well-defined structures.

Iron-Catalyzed Aerobic Oxidative Cross-Dehydrogenative C(sp3)–H/X–H (X = C, N, S) Coupling Reactions

Synlett ◽  
2020 ◽  
Vol 31 (18) ◽  
pp. 1753-1759
Author(s):  
Da-Zhen Xu ◽  
Ren-Ming Hu ◽  
Yi-Huan Lai
Keyword(s):  
Molecular Oxygen ◽  
Bond Formation ◽  
Research Topic ◽  
Synthetic Chemistry ◽  
Coupling Reactions ◽  
Iron Salts ◽  
Dehydrogenative Coupling ◽  
Recent Developments ◽  
Direct Functionalization ◽  
Made In

The direct functionalization of C(sp3)–H bonds is an attractive research topic in organic synthetic chemistry. The cross-dehydrogenative coupling (CDC) reaction provides a simple and powerful tool for the construction of C–C and C–heteroatom bonds. Recently, some progress has been made in the iron-catalyzed aerobic oxidative CDC reactions. Here, we present recent developments in the direct functionalization of C(sp3)–H bonds catalyzed by simple iron salts with molecular oxygen as the terminal oxidant.1 Introduction2 C(sp3)–C Bond Formation3 C(sp3)–N Bond Formation4 C(sp3)–S(Se) Bond Formation5 Conclusion and Outlook

scholarly journals Recent developments in synthetic chemistry and biological activities of pyrazole derivatives

2019 ◽  
Vol 131 (8) ◽  
Author(s):  
Muhammad Faisal ◽  
Aamer Saeed ◽  
Sarwat Hussain ◽  
Parsa Dar ◽  
Fayaz Ali Larik
Keyword(s):  
Biological Activities ◽  
Synthetic Chemistry ◽  
Pyrazole Derivatives ◽  
Recent Developments

Trends in Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 228-229
Author(s):  
C. Colliex ◽  
P. Trebbia
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Analytical Technique ◽  
Recent Developments ◽  
Quantitative Results ◽  
Electron Microscopes ◽  
Electron Energy Loss ◽  
Primary Electrons

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.

Filaments and membranes in the mitotic apparatus

1983 ◽  
Vol 41 ◽  
pp. 544-547
Author(s):  
Kent McDonald
Keyword(s):  
Intermediate Filaments ◽  
Mitotic Spindle ◽  
Mitotic Apparatus ◽  
Light Microscope Level ◽  
Microtubule Associated Proteins ◽  
Recent Developments ◽  
Associated Proteins ◽  
Force Generator ◽  
Spindle Function ◽  
Antibody Technology

At the light microscope level the recent developments and interest in antibody technology have permitted the localization of certain non-microtubule proteins within the mitotic spindle, e.g., calmodulin, actin, intermediate filaments, protein kinases and various microtubule associated proteins. Also, the use of fluorescent probes like chlorotetracycline suggest the presence of membranes in the spindle. Localization of non-microtubule structures in the spindle at the EM level has been less rewarding. Some mitosis researchers, e.g., Rarer, have maintained that actin is involved in mitosis movements though the bulk of evidence argues against this interpretation. Others suggest that a microtrabecular network such as found in chromatophore granule movement might be a possible force generator but there is little evidence for or against this view. At the level of regulation of spindle function, Harris and more recently Hepler have argued for the importance of studying spindle membranes. Hepler also believes that membranes might play a structural or mechanical role in moving chromosomes.

Software pattern recognition applied to nanodiffraction patterns from a STEM instrument

1986 ◽  
Vol 44 ◽  
pp. 694-695
Author(s):  
G.Y. Fan ◽  
J.M. Cowley
Keyword(s):  
Image Processing ◽  
Pattern Recognition ◽  
Computer Software ◽  
Processing System ◽  
Light Level ◽  
Host Computer ◽  
Low Light ◽  
Image Processing System ◽  
Recent Developments ◽  
On Line

In recent developments, the ASU HB5 has been modified so that the timing, positioning, and scanning of the finely focused electron probe can be entirely controlled by a host computer. This made the asynchronized handshake possible between the HB5 STEM and the image processing system which consists of host computer (PDP 11/34), DeAnza image processor (IP 5000) which is interfaced with a low-light level TV camera, array processor (AP 400) and various peripheral devices. This greatly facilitates the pattern recognition technique initiated by Monosmith and Cowley. Software called NANHB5 is under development which, instead of employing a set of photo-diodes to detect strong spots on a TV screen, uses various software techniques including on-line fast Fourier transform (FFT) to recognize patterns of greater complexity, taking advantage of the sophistication of our image processing system and the flexibility of computer software.

High-resolution microscopy of twin boundaries in gold

1987 ◽  
Vol 45 ◽  
pp. 260-261
Author(s):  
William Krakow ◽  
David A. Smith
Keyword(s):  
High Resolution ◽  
Specimen Preparation ◽  
Gold Films ◽  
Boundary Area ◽  
Transmission Electron ◽  
Recent Developments ◽  
Tilt Boundaries ◽  
High Resolution Microscopy ◽  
Twist Boundaries

Recent developments in specimen preparation, imaging and image analysis together permit the experimental determination of the atomic structure of certain, simple grain boundaries in metals such as gold. Single crystal, ∼125Å thick, (110) oriented gold films are vapor deposited onto ∼3000Å of epitaxial silver on (110) oriented cut and polished rock salt substrates. Bicrystal gold films are then made by first removing the silver coated substrate and placing in contact two suitably misoriented pieces of the gold film on a gold grid. Controlled heating in a hot stage first produces twist boundaries which then migrate, so reducing the grain boundary area, to give mixed boundaries and finally tilt boundaries perpendicular to the foil. These specimens are well suited to investigation by high resolution transmission electron microscopy.

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