Note 13 - Subsequent Events	6 Months Ended
Jun. 30, 2019
Notes to Financial Statements
Subsequent Events [Text Block]	13. Subsequent Events Stock Transactions On July 16, 2019, we entered into Exchange Agreements with holders of our Series F and Series G Preferred Stock, pursuant to which the holders exchanged all shares of Series F and Series G Preferred Stock held by them for an aggregate of 3,257 shares of Series H Convertible Preferred Stock (“Series H Preferred Stock”). Each share of Series H Preferred Stock is entitled to a liquidation preference equal to its $1,000 stated value, has no voting rights, and is not entitled to a dividend. The Series H Preferred Stock is convertible at any time at the option of the holders into shares of our common stock, at a conversion price equal to the lesser of (i) $7.50 per share and (ii) 80% of the lowest volume weighted average price of the common stock during the ten trading days immediately preceding the delivery of a notice of conversion. The Series H Preferred Stock contains price adjustment provisions, which may, under certain circumstances reduce the conversion price to match if we sell or grant options to purchase, including rights to reprice, our common stock or common stock equivalents at a price lower than the then conversion price of the Series F Preferred Stock. On July 24, 2019, we entered into a Securities Purchase Agreement with the purchasers identified therein (the “Purchasers”) providing for sale to the Purchasers of an aggregate of 700 shares of our Series I Convertible Preferred Stock (“Series I Preferred Stock”) for gross proceeds of $700,000. Each share of Series I Preferred Stock is entitled to a liquidation preference equal to its $1,000 stated value, has no voting rights, and is not entitled to a dividend. The Series I Preferred Stock is convertible at any time at the option of the holders into shares of our common stock, at a conversion price equal to the lesser of (i) $7.50 per share and (ii) 80% of the lowest volume weighted average price of the common stock during the ten trading days immediately preceding the delivery of a notice of conversion. The Series I Preferred Stock contains price adjustment provisions, which may, under certain circumstances reduce the conversion price to match if we sell or grant options to purchase, including rights to reprice, our common stock or common stock equivalents at a price lower than the then conversion price of the Series I Preferred Stock. During July and August 2019, holders of our preferred stock converted 46 shares of our Series F Preferred Stock into 88,400 shares of our common stock and 171 shares of our Series H Preferred Stock into 1,737,441 shares of our common stock. During August 2019, we issued 37,827 shares of our common stock in exchange for consulting services.

13.

Subsequent Events

Stock

Transactions

July 16, 2019,

we entered into Exchange Agreements with holders of our Series F and Series G Preferred Stock, pursuant to which the holders exchanged all shares of Series F and Series G Preferred Stock held by them for an aggregate of

3,257

shares of Series H Convertible Preferred Stock (“Series H Preferred Stock”). Each share of Series H Preferred Stock is entitled to a liquidation preference equal to its

$1,000

stated value, has

voting rights, and is

not

entitled to a dividend. The Series H Preferred Stock is convertible at any time at the option of the holders into shares of our common stock, at a conversion price equal to the lesser of (i)

$7.50

per share and (ii)

80%

of the lowest volume weighted average price of the common stock during the

ten

trading days immediately preceding the delivery of a notice of conversion. The Series H Preferred Stock contains price adjustment provisions, which

may,

under certain circumstances reduce the conversion price to match if we sell or grant options to purchase, including rights to reprice, our common stock or common stock equivalents at a price lower than the then conversion price of the Series F Preferred Stock.

July 24, 2019,

we entered into a Securities Purchase Agreement with the purchasers identified therein (the “Purchasers”) providing for sale to the Purchasers of an aggregate of

700

shares of our Series I Convertible Preferred Stock (“Series I Preferred Stock”) for gross proceeds of

$700,000.

Each share of Series I Preferred Stock is entitled to a liquidation preference equal to its

$1,000

stated value, has

voting rights, and is

not

entitled to a dividend. The Series I Preferred Stock is convertible at any time at the option of the holders into shares of our common stock, at a conversion price equal to the lesser of (i)

$7.50

per share and (ii)

80%

of the lowest volume weighted average price of the common stock during the

ten

trading days immediately preceding the delivery of a notice of conversion. The Series I Preferred Stock contains price adjustment provisions, which

may,

During

July

and

August 2019,

holders of our preferred stock converted

shares of our Series F Preferred Stock into

88,400

shares of our common stock and

171

shares of our Series H Preferred Stock into

1,737,441

shares of our common stock. During

August 2019,

we issued

37,827

shares of our common stock in exchange for consulting services.