7. Share-based payments (Details 3)	6 Months Ended	12 Months Ended
Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividend yield	0.00%
Nonemployee Common stock warrants [Member]
Volatility	144.00%
Risk-free interest rate	1.50%
Expected life (years)	3 years
Dividend yield	0.00%
Nonemployee Common stock warrants - Fully-vested [Member]
Dividend yield
Nonemployee Common stock warrants - Fully-vested [Member] \| Minimum [Member]
Volatility		102.00%	121.00%
Risk-free interest rate		0.50%	1.40%
Expected life (years)		1 year	3 years
Nonemployee Common stock warrants - Fully-vested [Member] \| Maximum [Member]
Volatility		272.00%	173.00%
Risk-free interest rate		1.50%	1.60%
Expected life (years)		5 years	4 years

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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