The phrase "and markedly more" is correct and usable in written English.
It can be used to indicate a significant increase or improvement in comparison to something else.
Example: "The new software is efficient, user-friendly, and markedly more effective than the previous version."
Alternatives: "and significantly more" or "and considerably more".
At Saturday's rally, Mr. Abhisit's speech was earthy and markedly more aggressive than his previous remarks.
Regardless of how it happened, today's N.B.A. players are heavier and markedly more muscled, and the game is tailored to their strengths.
Two friends, Stein and Ben, would be backpacking for the first time, each wearing new shoes and markedly more carefree dispositions than either me or my girlfriend, Rachel.
Because if you open up the Pandora's box marked But Why Did You Vote Brexit, Granny?, you're a bolder – and markedly more patient – person than I am.
Foams based on the fluorosurfactants contained many small cells while the others showed larger and markedly more irregular cells.
Non-survivors had also significantly fewer ICU hospital days (14 days vs. 19 days p = 0.045) and markedly more days free from mechanical ventilation (6 days vs. 14 days p = 0.036).
Also, in the patients with severe SIRS and sepsis, and shock, markedly more patients were under-classified with the 1992 definitions as compared to the 2003 definitions.
Based on the EC50 values, TP and Aro150 were the most toxic components and were markedly more toxic than TEP and DMA.
S. suis ST-7 expressed the proposed virulence markers muramidase-released protein (MRP), extracellular protein factor (EF), and hemolysin (named suilysin) (9– 11) and was markedly more cytototoxic to human peripheral blood mononuclear cells (PBMC) than a representative ST-1 strain.
Morphological alterations of HeLa cells treated with prDelta were observed at 4°C and were markedly more pronounced after incubation at 37°C (Figure 7A and C).
Numerical results show that the proposed design adequately controls the Type I error rate, has a minimal loss in power under the proportional hazards setting and is markedly more powerful than the log-rank test with a delayed treatment effect.
