摘要:
A chiral (R) stereospecific polyhydroxyalkanoate (PHA) in aqueous latex form having virgin disperse phase particles of very low or undetectable crystallinity is useful in making a water-sensitive structure water-resistant. It may be used as a mixture with a latex of a synthetic polymer. Processes for making the PHA latex are disclosed.
摘要:
The present invention provides for a method of culturing cells and inducing the expression of at least one gene in the cell culture. The method provides for contacting the cell with a transcription factor decoy oligonucleotide sequence comprising a nucleotide sequence encoding a shear stress response element.
摘要:
Polyester composition comprising a biodegradable polyester and a plasticising quantity of at least one plasticiser selected from the group: high-boiling esters of polybasic acids; phosphoric acid derivatives; phosphorous acid derivatives; phosphonic acid derivatives; substituted fatty acids; high-boiling glycols, polyglycols, polyoxyalkylenes and glycerol each optionally substituted and optionally terminally esterified; pentaerythritols and derivatives; sulphonic acid derivatives; epoxy derivatives; chlorinated paraffins; polymeric esters; Wolflex-But*; provided that citrates does not include doubly esterified hydroxycarboxylic acids having at least 3 ester groups in its molecule and further provided that glycerols does not include glycerol triacetate and glycerol diacetate.
摘要:
The present invention provides a method for production of functional proteins including hormones by renal cells in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-a-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.
摘要:
A polymer composition comprises (a) a stereospecific, preferably fermentation derived, polyester of molecular weight Mw over 100000 consisting of repeating units of formula --O--C.sub.m H.sub.n --CO-- in which n=2m and units with m=3 and m=4 with respectively a C.sub.1 and C.sub.2 side group on the carbon atom next to oxygen in the polymer chain are copolymerised together, m being 3 in 70-95 mol percent of such units; and (b) at least one alkyl phenol in which the alkyl group preferably contains at least one tertiary carbon atom adjacent to or within 4 carbon atoms of the phenol nucleus. The alkyl phenol may be hindered and may contain a C.sub.1-6 alkoxy group para to the phenolic hydroxy group. Suitable alkyl phenols include 2-tert-butyl-4-hydroxy-anisole and alpha- or delta- tocopherol and others usable as antioxidants in foods, oils and polymer systems. The polyester and alkyl phenol and relative proportions thereof are preferably chosen to provide inhibition of crystallisation of the polyester corresponding to an Avrami `k` parameter less than 0.03.
摘要:
A hydroxycarboxylic acid copolyester of R-stereospecific configuration contains a majority of first repeating units capable of forming a highly crystalline high-melting homopolyester and a minority of second repeating units capable when randomly copolycondensed with said first repeating units of lowering the melting point of said homopolyester and is characterised by one or more of: higher crystalline melting point, shorter crystallising time, higher notched impact strength at age 1 month, as compared with corresponding random polyester, and said majority repeating units in the polyester chain being present in blocks longer than correspond to their over-all molar proportionality. The copolyester may be made by fermentation, controlling the distribution of repeating units by reference to the pattern of feeding substrates corresponding to the respective repeating units.
摘要:
Polymer compositions are provided which comprise a first polyhydroxyalkanoate component and optionally a second polymer component, the composition have enhanced properties by using an inorganic oxygen containing compound in the composition. The inorganic oxygen containing compound may be acting as a transesterification catalyst.
摘要:
A polymer composition comprising at least one structural polymer and at least one oligomer of at least one polymer selected from the group; polyhydroxyalkanoates, polylactide, polycaprolactone and co-polymers thereof.
摘要:
A binder composition for producing articles of bonded particulate material such as foundry moulds or cores comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.
摘要:
A binder composition for producing articles of bonded particulate material such as foundry moulds or cones comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.