17.  Subsequent Events

On October 18, 2016, the Company entered into a securities purchase agreement with certain accredited investors, pursuant to which the Company agreed to sell 3,600,000 shares of common stock, pre-funded Series B warrants to purchase up to 2,700,000 shares of common stock, and Series A warrants to purchase up to 6,300,000 shares of common stock. Pursuant to a placement agent agreement, dated as of October 18, 2016, the Company engaged Oppenheimer & Co. Inc. as the lead placement agent for the offering and ROTH Capital Partners, LLC as co-placement agent for the offering. Each share of common stock was sold at a price of $1.20. Each Series B warrant was issued with an exercise price of $1.20 per share of common stock, $1.19 of which was pre-funded at closing and $0.01 of which will be payable upon exercise. Each Series A warrant was issued with an initial exercise price of $1.34 per share of common stock, subject to adjustment for certain dilutive issuances. The net proceeds to the Company from this offering, after deducting the placement agent fees and other estimated offering expenses, were approximately $6.8 million. The offering closed on October 21, 2016. In connection with the offering, the Company is subject to a lock-up that expires in March 2017, with certain issuances of securities by the Company being exempt from the lock-up.