is expressing significant concerned vs is expressing significant concern

Some examples from the web:

• And young Miss Linton is expressing some misgivings.
• Is expressing his own way, of course, because...
• Mr President, Parliament is expressing serious concern about the progress of the negotiations at the Intergovernmental Conference.
• My subconscious self is expressing irrational fears, which I also choose to ignore.
• Today and tomorrow the European Parliament is expressing solidarity with the Tibetan people.
• And if one of those particular things is expressing in your body, then you take Gleevec and you're cured.
• In the case of China, the Council is expressing itself with far more restraint.
• There are a lot of people who have taken up this point, so that Parliament is expressing a strong opinion on the matter.
• When Mr Le Pen holds forth on the inequality of races, he is expressing a great ideological continuity.
• Primarily, Europe is expressing economic interests, which disregard the problems involved in securing a lasting peace and democratization combined with respect for human rights.
• Mr President, I should like to make it clear once more that Mr Sakalas is expressing a personal opinion here.
• Mr President, Northern Ireland has a very vibrant poultry industry, which is expressing grave concern.
• Any child who is failing is expressing his unease in the educational institution, but also in society.
• Living is expressing what you feel, what you think.
• This very week a major conference in the United States is expressing fears about the inability of developed and developing societies alike to combat and prevent the resurgence of diseases thought to be beaten.
• Mr President, Mr Commissioner, on the eve of the election in Djibouti, this Parliament is expressing its concern with the political developments in the country.
• The report essentially deals with the outlook for the ultraperipheral regions and OCTs, and that is what the European Parliament is expressing its opinion on today.
• The World Bank is including poverty reduction programmes in its plans, and is expressing concern about countries such as Tanzania which spend more on debt servicing than either health or education.
• I am extremely pleased that Mr Cashman is expressing a wise position - one which Mrs Schörling has also put forward and with which I agree.
• Besides, while the European Parliament is expressing its indignation, those States which make up the Union are continuing to maintain relations with the leaders of those countries.

Some examples from the web:

• And young Miss Linton is expressing some misgivings.
• Against this backdrop, the present Common Resolution meets the most significant concerns and makes some highly relevant points.
• Currently, there is significant concern about funding for a universal service.
• The market investigation did not raise significant concerns in relation to this product.
• If someone's using the market to sell stolen goods, that's of significant concern.
• However, no significant concerns for financial stability have been identified to date, as electronic channels are still of limited importance for the majority of banks.
• For this reason, merchants have expressed significant concerns about the side-effects of SEPA migration.
• The failure of last week's Parliament-Council Conciliation Committee meeting has caused significant concern throughout the European Union.
• Significant concerns have been expressed about this proposed acquisition not only as regards effective competition and consumer welfare but also in relation to data protection and privacy.
• It is a matter that has been of significant concern to the Industry Committee.
• Is expressing his own way, of course, because...
• Mr President, Parliament is expressing serious concern about the progress of the negotiations at the Intergovernmental Conference.
• My subconscious self is expressing irrational fears, which I also choose to ignore.
• Today and tomorrow the European Parliament is expressing solidarity with the Tibetan people.
• With regard to the finances, the economic viability of the sector is a significant concern in Europe.
• There is no doubt that there are significant concerns about the cost of the proposed directive, especially those sections on contaminated land and national inventories.
• As the rapporteur clearly states, the intention of creating a full Open Aviation Area between these two countries, an issue with which we have raised significant concerns, does not fall within the scope of this Agreement, but should be the subject of a separate recommendation.
• President Obama himself acknowledged, in his Executive Order to close Guantanamo, 'the significant concerns raised by these detentions, both within the US and internationally'.
• Systems based around dibasic esters (DBEs) - mixtures of dimethyl adipate, succinate and glutarate - currently look to be the most promising alternatives, with little to suggest that there are any significant concerns for human health or the environment.
• And if one of those particular things is expressing in your body, then you take Gleevec and you're cured.