摘要:
In one or more embodiments, the present invention provides a novel approach to the addition of plasticizers for softening TPUs, i.e., lowering the durometer and the melt viscosity. This approach involves incorporating bonded sulfonate groups with quaternary ammonium counterions into the TPU. In one or more embodiments of the present invention, the softening of TPU is achieved by incorporating an ionic diol, such as N,N-bis (2-hydoxyethyl)-2-aminoethane-sulfonic acid (BES), coupled with various bulky alkyl ammonium cations, during the chain extension step of the TPU synthesis. It is believed that that steric hindrance of the bulky quaternary ammonium groups weakens the dipole-dipole interactions of the sulfonate groups and/or lowers the crystallinity of the hard block, thereby creating additional free volume that softens the polymer and lowers the melt viscosity.
摘要:
The present invention is directed to a covalently crosslinked hydrogel comprising the strain-promoted reaction product of an 8-member cycloalkyne functionalized polyalkylene glycol and a multi-arm glycerol exytholate triazide and methods for making them. Because the precursor materials can be manipulated without causing crosslinking, provided the strain threshold is not reached, these hydrogels permit mechanical control over when (and where) cross linking occurs and are easier to use than prior strain-activated or temperature-activated systems. These novel hydrogels do not require a catalyst to cross link, thus avoiding the biocompatibility problems common to many catalysts. Nor is the crosslinking process affected by the presence of catalysts or other substances, which have interfered with crosslinking in known strain induced hydrogels. Because of their crosslinking reaction kinetics, these novel hydrogels can encapsulate and transport highly sensitive cells and other biological additives and have no known toxic byproducts.
摘要:
The present invention is directed to a covalently crosslinked hydrogel comprising the strain-promoted reaction product of an 8-member cycloalkyne functionalized polyalkylene glycol and a multi-arm glycerol exytholate triazide and methods for making them. Because the precursor materials can be manipulated without causing crosslinking, provided the strain threshold is not reached, these hydrogels permit mechanical control over when (and where) cross linking occurs and are easier to use than prior strain-activated or temperature-activated systems. These novel hydrogels do not require a catalyst to cross link, thus avoiding the biocompatibility problems common to many catalysts. Nor is the crosslinking process affected by the presence of catalysts or other substances, which have interfered with crosslinking in known strain induced hydrogels. Because of their crosslinking reaction kinetics, these novel hydrogels can encapsulate and transport highly sensitive cells and other biological additives and have no known toxic byproducts.
摘要:
A method of creating biocompatible polymeric structures includes the steps of: providing a biocompatible polymer including a strained cycloalkyne end group; forming a polymeric structure from the biocompatible polymer such that the strained cycloalkyne end group remains on the biocompatible polymer; providing an azide tethered molecule; and, after forming the polymeric structure, reacting the azide tethered molecule with the cycloalkyne in an azide alkyne cycloaddition reaction to further functionalize the polymeric structure.
摘要:
A web conversion method based on phone calls is disclosed. Some embodiments comprise distributing a multiplicity of ads across a multiplicity of online media channels, displaying a unique advertiser phone number on each ad for a limited time every time a prospect visits a webpage hosting the ad, determining that the prospect called the advertiser phone number within the limited time, determining that the geographical zone of the prospect at the time of the call encompasses the geographical location of the IP address at where the unique phone number is displayed, and charging an advertiser for the ad that displayed the advertiser phone number.
摘要:
According to an embodiment of the invention, a method and apparatus for signal modulation are described. According to an embodiment of the invention, a method comprises producing and transferring a modulated signal. The modulation of the signal is over a plurality of amplitude levels, including at least a first amplitude level, a second amplitude level and a third amplitude level, and over a plurality of time slots, including at least a first time slot, a second time slot, and a third time slot. The modulated signal transitions from the first amplitude level to the second amplitude level in the first phase slot, remains at the second amplitude level in the second time slot, and transitions from the second amplitude level to the third amplitude level in a third time slot.
摘要:
A method of creating a black box timing model for a digital circuit. The digital circuit is characterized by a block model having at least one input and at least one output. The method determines a delay statement for the output of the block model. The method also determines an input set-up constraint for the input of the block model. The input set-up constraint is based upon the delay statement. The model is then used with a static timing analyzer to accurately model a flow-through circuit.
摘要:
A method and a system for static timing analysis of a latch-based circuit. A netlist data structure represents the latch-based circuit. The method statically analyzes the netlist data structure and produces timing information for signal paths within the latch-based circuit. The signal paths are filtered using path termination information, which specifies where paths end. The path termination information distinguishes a first signal path that terminates at a latch from a second signal path that flows through that same latch.
摘要:
In various aspects, the present invention is directed to novel bioactive peptide loaded poly(propylene fumarate) (PPF) tissue scaffolds and related methods for their making and use. In various embodiments, these bioactive peptide loaded poly(propylene fumarate) tissue scaffolds are formed by forming a PPF structure or matrix using photochemical 3-D printing techniques and then loading that printed PPF structure or matrix with a bioactive peptides or other bioactive compounds that have, or have been functionalized to have, a thiol functional group at or near its terminus. The thiol groups on the bioactive peptides or other compound will react with exposed alkene functional groups on the PPF polymer matrix via a thiol-ene “click” reaction, thereby binding these bioactive peptides or other compounds to the tissue scaffolds. The bioactive peptide loaded PPF tissue scaffolds of the present invention are particularly useful in repairing bone defects.