Recent Advances in 2D Imaging of Element Distribution in Plants by Focused Beam Techniques

2019 ◽  
pp. 169-207
Author(s):  
Katarina Vogel-Mikuš ◽  
Johannes Teun van Elteren ◽  
Marjana Regvar ◽  
Jitrin Chaiprapa ◽  
Boštjan Jenčič ◽  
...  
Keyword(s):  
Element Distribution ◽  
Recent Advances ◽  
2D Imaging ◽  
Focused Beam

Recent Advances in High Dispersion Spectroscopy of Globular Cluster Stars

1988 ◽  
Vol 132 ◽  
pp. 525-530
Author(s):  
Raffaele G. Gratton
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
High Dispersion ◽  
Photographic Material ◽  
Recent Advances ◽  
Metal Abundances ◽  
Ccd Detectors ◽  
Major Progress

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

Electron spectroscopic imaging (ESI) on multiphase polymer materials

1989 ◽  
Vol 47 ◽  
pp. 348-349
Author(s):  
H.-J. Cantow ◽  
M. Kunz ◽  
M. Möller
Keyword(s):  
Energy Loss ◽  
Melt Spinning ◽  
Chromatic Aberration ◽  
Element Distribution ◽  
Polymer Materials ◽  
Specific Energy Loss ◽  
Transmission Electron ◽  
Multicomponent Polymer ◽  
Diffraction Patterns ◽  
Image Planes

In transmission electron microscopy the natural contrast of polymers is very low. Thus the contrast has to be enhanced by staining with heavy metals. The resolution is limited by the size of the staining particles and by the fact that electrons with different energy are focused in different image planes due to the chromatic aberration of the magnetic lenses. The integration of an electron energy loss spectrometer into the optical coloumn of a transmission electron microscope offers the possibility to use monoenergetic electrons and to select electrons with a certain energy for imaging. Thus contrast and resolution are enhanced. By imaging only electrons with an element specific energy loss the element distribution in the sample can be obtained. In addition, elastic bright field images and diffraction patterns yield excellent resolution. Some applications of the method on multicomponent polymer materials are discussed.Bulk polymer samples were prepared by ultramicrotoming at room temperature or well below the glass transition temperature. Very thin films for the direct observation of the structure in semicrystalline polymers were obtained by melt-spinning. Specimens were examined with a ZEISS CEM 902 operated at 80 kV.

Chelation-assisted transition metal-catalysed C–H chalcogenylations

2020 ◽  
Vol 7 (8) ◽  
pp. 1022-1060 ◽  
Author(s):  
Wenbo Ma ◽  
Nikolaos Kaplaneris ◽  
Xinyue Fang ◽  
Linghui Gu ◽  
Ruhuai Mei ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Advances ◽  
Site Selectivity ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

This review summarizes recent advances in C–S and C–Se formations via transition metal-catalyzed C–H functionalization utilizing directing groups to control the site-selectivity.

Nucleosome dynamics

2006 ◽  
Vol 73 ◽  
pp. 109-119 ◽  
Author(s):  
Chris Stockdale ◽  
Michael Bruno ◽  
Helder Ferreira ◽  
Elisa Garcia-Wilson ◽  
Nicola Wiechens ◽  
...  
Keyword(s):  
High Resolution ◽  
Chromatin Structure ◽  
Current Knowledge ◽  
Dynamic Properties ◽  
Structure And Dynamics ◽  
Nucleosome Dynamics ◽  
Sharp Focus ◽  
Recent Advances ◽  
Insight Into ◽  
Chromatin Structure And Dynamics

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.

Recent Advances in the Treatment of Pulmonary Tuberculosis

1950 ◽  
Vol 34 (5) ◽  
pp. 1363-1380
Author(s):  
Theodore L. Badger ◽  
William E. Patton
Keyword(s):  
Pulmonary Tuberculosis ◽  
Recent Advances

Recent Advances in Thyroid Imaging

1990 ◽  
Vol 23 (2) ◽  
pp. 251-270
Author(s):  
Martin P. Sandler, MD ◽  
James A. Patton ◽  
Robert H. Ossoff
Keyword(s):  
Thyroid Imaging ◽  
Recent Advances

A Dynamic Systems Approach to Personality

2001 ◽  
Vol 6 (3) ◽  
pp. 172-176 ◽  
Author(s):  
Lawrence A. Pervin
Keyword(s):  
Dynamic Systems ◽  
Systems Approach ◽  
Biological Processes ◽  
Recent Advances ◽  
Dynamic View ◽  
The Future ◽  
History Of

David Magnusson has been the most articulate spokesperson for a holistic, systems approach to personality. This paper considers three concepts relevant to a dynamic systems approach to personality: dynamics, systems, and levels. Some of the history of a dynamic view is traced, leading to an emphasis on the need for stressing the interplay among goals. Concepts such as multidetermination, equipotentiality, and equifinality are shown to be important aspects of a systems approach. Finally, attention is drawn to the question of levels of description, analysis, and explanation in a theory of personality. The importance of the issue is emphasized in relation to recent advances in our understanding of biological processes. Integrating such advances into a theory of personality while avoiding the danger of reductionism is a challenge for the future.

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