English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Motivation: Cellular Electron CryoTomography (CECT) is an emerging 3D imagingtechnique that visualizes subcellular organization of single cells atsubmolecular resolution and in near-native state. CECT captures large numbersof macromolecular complexes of highly diverse structures and abundances.However, the structural complexity and imaging limits complicate the systematicde novo structural recovery and recognition of these macromolecular complexes.Efficient and accurate reference-free subtomogram averaging and classificationrepresent the most critical tasks for such analysis. Existing subtomogramalignment based methods are prone to the missing wedge effects and lowsignal-to-noise ratio (SNR). Moreover, existing maximum-likelihood basedmethods rely on integration operations, which are in principle computationallyinfeasible for accurate calculation.  Results: Built on existing works, we propose an integrated method, FastAlignment Maximum Likelihood method (FAML), which uses fast subtomogramalignment to sample sub-optimal rigid transformations. The transformations arethen used to approximate integrals for maximum-likelihood update of subtomogramaverages through expectation-maximization algorithm. Our tests on simulated andexperimental subtomograms showed that, compared to our previously developedfast alignment method (FA), FAML is significantly more robust to noise andmissing wedge effects with moderate increases of computation cost.Besides, FAMLperforms well with significantly fewer input subtomograms when the FA methodfails. Therefore, FAML can serve as a key component for improved constructionof initial structural models from macromolecules captured by CECT.

An integration of fast alignment and maximum-likelihood methods for electron subtomogram averaging and classification