Document:

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                                                                   EXHIBIT 10.14

                       SELLER NOTE MODIFICATION AGREEMENT

BETWEEN:

MAKER:   Accent Optical Technologies, Inc. (formerly Accent Semiconductor
         Technologies, Inc.)

And

PAYEE:   Bio-Rad Laboratories, Inc.

And

BANK:    Comerica Bank-California

SELLER NOTE:

That certain Seller Note of Maker in favor of Payee in the original principal
amount of $8,000,000 dated July 31, 2000.

                                    RECITALS

         a.       Payee is the holder of the Seller Note.

         b.       Bank is providing up to $7,500,000 in credit facilities to
                  Payee pursuant to a Loan and Security Agreement dated December
                  18, 2002 between Maker, AOTI Operating Company, Inc. and Bank
                  ("Comerica Debt").

         c.       A portion of the Comerica Debt will be used to pay off the
                  debt of Payee to Fleet National Bank, which debt was
                  "Designated Senior Debt" as defined under the terms of the
                  Seller Note.

         d.       The payment obligations and security interests (if any) under
                  the Seller Note are subordinated to Designated Senior Debt and
                  Designated Senior Debt enjoys certain other protections for
                  payment under the terms of the Seller Note.

         e.       Because the Comerica Debt is less than $25,000,000, it cannot
                  be designated as Designated Senior Debt under the current
                  provisions of the Seller Note.

         f.       The parties hereto desire to amend the Seller Note to allow
                  for the designation of the Comerica Debt as Senior Debt and
                  Designated Senior Debt as those terms are defined in the
                  Seller Note.

         g.       The Bank would be unwilling to provide the Comerica Debt
                  without this amendment, and Payee acknowledges that the
                  Comerica Debt is beneficial to Maker and thus indirectly
                  benefits Payee.

                                    AGREEMENT

Maker, Payee and Bank agree as follows:

                                                                          Page 1
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         1.       The Comerica Debt (specifically the "Obligations", as that
                  term is defined in the Loan and Security Agreement referred to
                  above) is hereby designated as Senior Debt and Designated
                  Senior Debt under the Seller Note.

         2.       Maker and Payee will not further amend, modify or alter the
                  terms of the Seller Note without the consent of Bank, which
                  consent will not be unreasonably withheld as to matters not
                  affecting the subordination of the Seller Note to the Comerica
                  Debt.

         3.       Except as specifically addressed in this Seller Note
                  Modification Agreement, all other terms and conditions of the
                  Seller Note remain in full force and effect.

         4.       This Seller Note Modification Agreement may be executed in two
                  or more counterparts, each of which shall be deemed an
                  original but all of which together shall constitute one and
                  the same instrument.

         5.       Each of the parties hereto agrees to execute all such further
                  instruments and documents and to take all such further action
                  as the other parties may reasonably require in order to
                  effectuate the terms and purposes of this agreement.

         Effective as of the 18th day of December, 2002.

MAKER:                               PAYEE:
Accent Optical Technologies, Inc.    Bio-Rad Laboratories, Inc.

By:   /s/                             By: /s/
    ------------------------------        -------------------------------
Its: President                        Its: Vice President and General Counsel

BANK:
Comerica Bank-California

By:   /s/
    ------------------------------
Its: Vice President

                                                                          Page 2<PAGE>

                                                                   EXHIBIT 10.15

                       SELLER NOTE MODIFICATION AGREEMENT
                                   NUMBER TWO

BETWEEN:

MAKER:       Accent Optical Technologies, Inc.
             (Formerly Accent Semiconductor Technologies, Inc.)

And

PAYEE:       Bio-Rad Laboratories, Inc.

And

BANK:        Comerica Bank (successor by merger to Comerica Bank- California)

SELLER NOTE: That certain Seller Note of Maker in favor of Payee in the original
             principal amount of $8,000,000 dated July 31, 2000, as modified by
             that certain Seller Note Modification Agreement dated December 18,
             2002.

                                    RECITALS

         a.       Payee is the holder of the Seller Note.

         b.       Maker desires to extend the maturity date of the Seller Note.

         c.       Payee is willing to accommodate Maker's desire to extend the
                  maturity date in exchange for the commencement of interest
                  payments in cash commencing in 2004.

         d.       Bank is willing to consent to this Seller Note Modification
                  Agreement Number Two ("Second Modification") in exchange for
                  and in conjunction with Maker entering into the Third
                  Amendment to Loan and Security Agreement.

                                    AGREEMENT

         Maker, Payee and Bank agree as follows:

1.       The "Maturity Date", as that term is defined in the Seller Note, is
         extended from July 31, 2005 until July 31, 2007.

Seller Note Modification Agreement Number Two                             PAGE 1

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2.       The third paragraph of the Seller Note, beginning with "Anything
         contained in this Note . . . " is replaced in its entirety to read as
         follows:

         During the period commencing on the date of issuance of this Note and
         ending on the June 30, 2003 Interest Payment Date, Maker had the
         option, on each Interest Payment Date arising within said time period,
         in lieu of paying accrued and unpaid interest in cash, to instead
         increase the principal amount of this Note in an aggregate amount equal
         to the amount of such accrued and unpaid interest which would otherwise
         be due (the amount of each such increase being "Additional Principal").
         On each such Interest Payment Date Maker did elect to increase
         principal in lieu of paying interest in cash, and said Additional
         Principal is due and payable on the Maturity Date.

         On the December 31, 2003 Interest Payment Date, Maker hereby elects, in
         lieu of paying accrued and unpaid interest in cash, to increase the
         principal amount of this Note in an aggregate amount equal to the
         amount of such accrued and unpaid interest which would otherwise be due
         (the amount of the December 31, 2003 increase being "12/31/03
         Additional Principal")

         Following the December 31, 2003 Interest Payment Date, Maker will no
         longer have the option to roll accrued and unpaid interest into the
         principal balance of this Note.

         On the June 30, 2004 Interest Payment Date, Maker will pay to Payee, in
         cash, in one lump sum, the following amounts:

         (i)      accrued and unpaid interest from January 1, 2004 to June 30,
                  2004; and

         (ii)     the 12/31/03 Additional Principal.

         Thereafter, until the Maturity Date, on each Interest Payment Date
         Maker will pay to Payee accrued and unpaid interest in cash.

3.       Except as specifically addressed in this Second Modification, all other
         terms and conditions of the Seller Note remain in full force and
         effect.

4.       This Second Modification may be executed in two or more counterparts,
         each of which shall be deemed an original but all of which together
         shall constitute one and the same instrument.

5.       Each of the parties hereto agrees to execute all such further
         instruments and documents and to take all such further action as the
         other parties may reasonably require in order to effectuate the terms
         and purposes of this Second Modification.

Seller Note Modification Agreement Number Two                             PAGE 2

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6.       Nothing herein shall prevent or estop the Bank from declaring a
         default, if applicable, under the terms of that certain Loan and
         Security Agreement with Maker dated December 18, 2002, as amended.

Effective as of the 20th day of November 2003.

MAKER:                                 PAYEE:

Accent Optical Technologies, Inc.      Bio-Rad Laboratories, Inc.

By:   /s/                              By:  /s/
    -------------------------------        ------------------------------------
Its: CFO                               Its: Vice President and General Counsel

BANK:
Comerica Bank

By:  /s/
    ------------------------------
Its: Vice President

Seller Note Modification Agreement Number Two                             PAGE 3Exhibit 10.32

                           MEMORANDUM OF UNDERSTANDING

      This Memorandum of Understanding by and between Hemispherx Biopharma, Inc.
having an address at One Penn Center, 1617 JFK Blvd, Suite 660, Philadelphia, PA
l9103- 1806, USA ("HEB") and Fujisawa Deutschland GmbH, having an address at
Berg-am-Laim-Strasse 129, 81673 Munchen, Germany ("F-DE").

      Whereas, HEB, together with its subsidiaries, owns patents in the United
States and Europe relating to the use of Ampligen(R) in the treatment of Chronic
Fatigue Syndrome ("CFS"), and

      Whereas, HEB is conducting a phase III clinical trial in the United States
utilizing Ampligen(R) in the treatment of CFS patients ("AMP 516"), and

      Whereas, HEB plans to seek approval for the commercial sale of Ampligen(R)
in the United States and Europe from the United States Food And Drug
Administration ("FDA") and the European Medicines Evaluation Agency ("EMEA"),
respectively, and

      Whereas, HEB wishes to establish agreements for the distribution of
Ampligen(R) for the treatment of CFS in Europe, and

      Whereas, F-DE is interested in exploring the feasibility of becoming a
distributor for Ampligen(R) for the treatment of CFS in Germany, Switzerland and
Austria ("Territory")

      Now, therefore, this Memorandum of Understanding

      1. Upon execution of this Memorandum of Understanding F-DE shall pay to
HEB an option fee of (Euro)400,000 Euros.

      2. F-DE shall have the exclusive right and option to enter into a
Distribution Agreement with HEB, or one of its subsidiaries, for the Territory,
from the date of the execution of this Memorandum of Understanding to and
including that date which is twelve (12) weeks following the later of F-DE being
provided
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            (a) Access to the full report of the Amp 516 clinical trial allowing
F-DE a complete understanding of AMP 516's efficacy and safety including a fully
statistical evaluation.

            (b) Introduction to three principal investigators in the Amp 516
clinical trial to obtain their views on the Amp 516 clinical trial.

      The provisions set forth on Exhibit "A" attached hereto shall be a part of
the Distribution Agreement, with any and all other terms and provisions of the
Distribution Agreement to be negotiated in good faith in a timely manner by the
Parties.

      3. From the date of the execution of this Memorandum of Understanding, HEB
shall cooperate fully with F-DE in the performance by F-DE of its due diligence
with respect to Ampligen(R), the Amp 516 clinical trial, HEB's patents and all
other matters relevant to the Distribution Agreement.

      4. In the event F-DE is not provided by HEB with the full report of the
Amp 516 clinical trial by May 31, 2004 and F-DE does not wish to exercise its
option to enter into the Distribution Agreement, HEB shall, on May 31, 2004,
refund to F-DE (Euro)200,000 Euros of the option fee.

      In the event F-DE is not provided by HEB with the full report of the Amp
516 clinical trial by December 31, 2004 and F-DE does not wish to exercise its
option to enter into the Distribution Agreement, HEB shall, on December 31,
2004, refund to F-DE the entire option fee of 400,000 Euros.

      In the event the results of the Amp 516 clinical trial does not confirm
the results of previous studies and/or the due diligence performed by F-DE
reveals negative results which can not be cured by HEB and F-DE does not wish to
exercise its option to enter into the Distribution Agreement, HEB shall refund
to F-DE (Euro)200,000 Euros of the option fee.

      5. It is the intention of HEB and F-DE that this Memorandum of
Understanding shall be executed no later than January 31, 2004.
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      6. Neither party, without the written consent of the other, shall disclose
or publish the existence of this Memorandum of Understanding, or its terms or
provisions, except to its affiliated companies and except as may be required by
any and all governmental rules, regulations and/or laws.

      7. This Agreement constitutes the whole understanding related to the
subject matter hereof between the parties and shall prevail on any other terms.

      Any amendment or modification to this Memorandum of Understanding shall
only be made in writing and shall only be valid when signed by the due
representatives of the parties.

      8. This Memorandum of Understanding shall be governed by and construed in
accordance with the laws of Switzerland, excluding its provisions regarding
conflict of laws.

      Any dispute arising between the parties concerning the validity,
interpretation or implementation of this Memorandum of Understanding which
cannot be settled by negotiation, shall be finally settled by arbitration in
English language under the Rules of Arbitration of the International Chamber of
Commerce by one or more arbitrators appointed in accordance with said Rules.
Place of arbitration shall be Zurich, Switzerland.

      HEMISPHERX BIOPHARMA, INC.:

      By:
          ----------------------------

      Title: /s/ Dr. William A. Carter
             -------------------------

      Date: January 23, 2004
             -------------------------

      FUJISAWA DEUTSCHLAND GMBH:

      Munich, 21 January 2004

      /s/ W. Tinhof                          /s/ W. Schoch
      ------------------------               ------------------------
      Dr. W. Tinhof, President               W. Schoch, Executive Vice President

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