The phrase "a rigid core" is correct and usable in written English.
It can be used to describe something that has a strong, unyielding center or foundation, often in a metaphorical sense.
Example: "The organization has a rigid core of values that guide all its decisions and actions."
Alternatives: "a firm foundation" or "a solid center".
Even some previously staunch advocates of a rigid core curriculum have moderated their views.
The importance of the porous structure of a soft particle comprising a rigid core and a porous layer on its electrophoretic behavior is investigated.
Although a large number of FXa inhibitors have been studied, each can be classified as either possessing a highly flexible or a rigid core scaffold.
The electrophoresis of a soft particle comprising a rigid core and a charged porous membrane layer in a narrow space is modeled.
Oligomeric or multidomain proteins, with domains surrounding a rigid core, have unlimited ability to concentrate stress, provided there are at least four domains.
The structure of trimestatin at 1.7 Å resolution reveals that a number of turns and loops form a rigid core stabilized by six disulfide bonds.
In conclusion, we have demonstrated the first application of EPR spectroscopy to the discotic columnar liquid crystal HAT6 using a rigid-core nitroxide SP designed and synthesized for this purpose.
Based on the active site alignment, a further step detects flexible regions within the binding site and uses a remaining rigid core for a superimposition of the generated ensemble.
As a common feature, they have a long rigid core with four benzene rings and a chiral chain (usually the same) at each end.
Overall, these techniques revealed the presence in these nanosystems of a gradient of flexibility from an internal rigid core towards a more flexible region located on their surface, as well as the absence of water content in both regions.
Although this debate is still active, recent crosslinking (Zhang et al., 2012), photobleaching (Padeganeh et al., 2013), and AFM experiments (Miell et al., 2013) suggest that most CENP-A-containing nucleosomes are octameric, with a more rigid core than canonical nucleosomes (Black et al., 2007).
