The phrase "alone are required" is grammatically correct and can be used in written English.
It can be used to emphasize that only certain elements or factors are necessary, excluding all others.
Example: "In this experiment, the chemicals alone are required to achieve the desired reaction."
Alternatives: "only are needed" or "solely are necessary".
Kickers alone are required to make their own cases.
Creep rupture and creep crack growth data alone are required and used to make the predictions.
In particular, you are required to implement at least 2*N of these additional techniques, where N is the number of people on your team (i.e. groups of three people need to implement six techniques, individuals working alone are required to implement only two, etc.).
On average between 2,000 and 7,000 workers alone are required for each race to go ahead.
Results of this research suggest that other factors besides low sulfate concentrations alone are required for low sulfur isotope fractionation between sulfate and pyrite in ancient sedimentary record.
The Night Lords are responsible for negotiating with neighbors to agree upon new spaces where artists can tag, but Belor notes that every Sprayfield artist is tasked with translating a chapter or character from the show into a unique concept, and that they alone are required to finance the operation.
For the 150 Harvard students who land the jobs for "Let's Go," traveling alone is required.
For example, instead of fossil fuels alone being required, the introduction of a system of carbon emissions permits brings in a new type of property required to make and supply a product, in addition to the fossil fuels themselves.
A dictionary, in fact, is less a list of meanings than a list of intentional uses, and more information than is provided by the text alone is required to determine which of those uses is being deployed on a particular occasion.
In Drosophila, the EF-Hand of Nkd alone is required for binding to Dvl [25], but curiously, Nkd mutant proteins lacking the EF-Hand are capable of rescuing nkd-/ mutants to adulthood [26].
In the first case, it is possible that residual endogenous HeLa-cell HCF-1 remaining after siRNA treatment is sufficient to support some but not all aspects of G1-to-S progression and that only Domain 1 or 2 alone is required to provide the missing activity.
