Program and General Information 1. All abstracts in aphabetical order of the first authors except for an introductory abstract on the workshop's topic A copy of the original announcement Microstructure diagnostics of modern materials by transmission electron microscopy - need for advanced diffraction techniques. Coupling template matching and precession electron diffraction for reliable identification of crystallite orientations and phases in TEM.
Advanced applications of crystallite and phase mapping in materials science: Examples of applications in metallurgy. Structural fingerprinting in the TEM and open access crystallographic databases.
The final data set contained unique reflections from 2. Phaser McCoy et al. The data were subjected to twinning analysis; however, twinning with this symmetry group is forbidden and therefore we ruled out twinning in our crystals. Electron scattering factors Gonen et al. The structure factors and coordinates of the final model were deposited in the Protein Data Bank with accession code 3J4G.
The authors wish to thank members of the Gonen lab and Goragot Wisedchaisri for helpful discussions. This work is dedicated to the memory of Prof K H Kuo. The funder had no role in study design, data collection and interpretation, or the decision to submit the work for publication. Competing interests The authors declare that no competing interests exist.
Author contributions DS, Conception and design, Acquisition of data, Analysis and interpretation of data, Drafting or revising the article. BLN, Conception and design, Acquisition of data, Analysis and interpretation of data, Drafting or revising the article. MGI, Conception and design, Acquisition of data, Analysis and interpretation of data, Drafting or revising the article. TG, Conception and design, Acquisition of data, Analysis and interpretation of data, Drafting or revising the article.
Shi D, Nannenga B. L, Iadanza M. An edited version of the letter sent to the authors after peer review is shown, indicating the substantive concerns or comments; minor concerns are not usually shown. Reviewers have the opportunity to discuss the decision before the letter is sent see review process. Similarly, the author response typically shows only responses to the major concerns raised by the reviewers.
Your article has been favorably evaluated by a Senior editor and 3 reviewers. The following individuals responsible for the peer review of your submission have agreed to reveal their identity: Stephen Harrison guest Reviewing editor , Richard Henderson, and Axel Brunger peer reviewers. The guest Reviewing editor and the other reviewers discussed their comments before we reached this decision, and the guest Reviewing editor has assembled the following comments to help you prepare a revised submission. This is an interesting paper reporting a successful, 2. Lysozyme has been a prototype for testing out new methods and approaches ever since Roberto Poljak crystallized it in the s.
It has also been studied recently by electron diffraction and imaging Nederhof et al. It would be helpful if the authors of the current paper cited the above publications.
What is Electron Crystallography? | SpringerLink
There is also Moukhametzianov et al. Although the authors have done well to navigate all the technical hurdles that have so far prevented anyone else from collecting a full set of 3D electron diffraction data, it is still not clear whether there is any practical advantage in using electrons over conventional X-rays for 3D crystals.
As Moukhametzianov et al. The central background of inelastically scattered electrons in the electron diffraction patterns the present authors show is quite high. This high background could be greatly improved by using a zero-loss energy filter to remove these electrons. The paper should discuss the issue of damage, include some damage statistics from the present work see item 2 in the revision requests, below , and mention the longer-term value of using a zero-loss energy filter. The authors have also used a very crude way to measure intensities, simply taking the highest intensity of each peak in the rotation series.
This would be greatly improved if the now fully established method of profile fitting that is used by the X-ray crystallographers and the methods for correcting partial reflection suggested below were implemented. See changes in Abstract requested below.
If the work could be repeated with zero-loss energy filtering, a better detector, plus proper estimation of intensities, we might then be in a better position to see how successful the technique is, and what potential it has. Nevertheless, this is a useful step along the way.
Electron crystallography found to work as well as X-ray crystallography only on smaller crystals
In other words, is the useful limit related to the number of electrons per Bragg peak? This perhaps suggests that low-dose electron diffraction data collection is ultimately limited by radiation damage or the number of electrons per Bragg peak, in contrast to XFELs where radiation damage is circumvented, even at high-photon flux. The authors should comment on this. It is curious why a new indexing program was developed. This chance in turn is related to the energy bandwidth of the electron beam, the crystal mosacity, crystal and detector parameters, and crystal size for very small crystals.
A discussion of these factors and parameters for this particular experiment would be useful.
Introduction to electron crystallography
Please specify details: did some of the blind tests produce an MR solution, but refinement was stuck at high Rfree? The explanation by dynamic scattering is possible, although could there be other possibilities, e. However, the comment on the limited availability of beam time is well taken. In this respect, the low-dose method presented by the authors could be an important staging method for XFEL experiments, and the combination of both experiments could be very powerful.
The following substantive points should be addressed in a revision. These maps are also discussed in the revised text.
However, once we began the analysis we found that the large number of partial intensities made it difficult to accurately track any individual spot over a complete data set of up to 90 frames. We therefore performed an additional experiment to quantify the effect of dose on spot intensities. Diffraction data was collected from a single lysozyme microcrystal using a dose of 0. In this way we could follow individual reflections throughout all frames and plotted the intensity values versus accumulated dose.
This new data is presented as Figure 3 and discussed in the revised text. We do not believe this is the case as even crystals significantly smaller than those used here contain more than enough unit cells to get strong Bragg peaks. We updated the text to reflect this point more clearly. A major limitation that we observed is likely because of inelastic scattering in thick crystals.
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We believe that we are not limited by the number of electrons per Bragg peak but instead inelastic scattering from crystals that are too thick is severely limiting the data. In this revised version of our manuscript we added data demonstrating that the achievable resolution is affected by crystal thickness.
These are presented in Figure 2A and 2D and described in the revised text. We note that data in our study was collected to 1. This resolution cut off is self imposed based on our current software limitations. As such we note that the resolution collected here is comparable to the study by Boutet et al. Science We updated the manuscript at various places including the Abstract to make this clearer. We apologize for the confusion and for not making this point clearer in the original version of our manuscript.
We did initially attempt to use MOSFLM to process our data but were met with several roadblocks that, although not insurmountable, made it more practical to develop some basic programs of our own for this initial proof of principal. We still believe that one of the future improvements of this work will be its integration into current data processing software used in X-ray crystallography. Text was added to the Discussion and Methods sections highlighting this point.
We added additional text to the Discussion to highlight these points and suggested how some future improvements to data collection may improve the accuracy of the measured intensities. Table 2 was added to provide this information. We do not believe that the crystal size played a role here.