Grafting induced

CO prevents graft-induced intimal hyperplasia in pigs [22],... 

I.M.1.5 Platelet Aggregation After Gel I.M.3.8.2 Eversion-Graft Induced... 

Lenschow, D.J., Zeng, Y., Thistlewaite, J.R, Montag, A., Brady, W., Gibson, M.L., Linsley, P.S. and Bluestone, J.A. (1992). Long-term survival of xenogeneic pancreatic islet grafts induced by CTLA-4-Ig. Science 257, 789-792. 

Grafting induced by radiation methods can be achieved either after preirradiation or simultaneously during the irradiation. In the latter, polymer film is embedded in a monomer solution which is directly grafted during the irradiation process. 

Monti-Bloch L, Stensaas, LJ, Eyzaguirre C. Carotid body grafts induce chemosensitivity in muscle nerve fibers of the cat. Brain Res 1983 270 77-92. 

Contamination of blood products with lymphocytes can lead to transfusion-induced reactions ranging from a mild fever to severe reactions such as alloimmunization and graft versus host disease (GvHD), in which the transfused lymphocytes (graft) survive the defensive immune reaction of the patient (host) and start a reaction which destroys the cells of the host. The patient also may develop an immune response to the human leukocyte antigen (HLA) type of the graft s cells and reject all platelet transfusions that do not match their own HLA system. The HLA system, found on blood platelets and lymphocytes, is more compHcated than, but similar to, the ABO blood group system of red cells. 

Modifications of epichlorohydrin elastomers by radical-induced graft polymeri2ation have been reported. Incorporated monomers include styrene and acrylonitrile, styrene, maleic anhydride, vinyl acetate, methyl methacrylate, and vinyHdene chloride (81), acryHc acid (82), and vinyl chloride (81,83,84). When the vinyl chloride-modified epichlorohydrin polymers were used as additives to PVC, impact strength was improved (83,84). 

The photo-induced process of modification of cellulose and its derivatives was reported by Geacintov and coworkers [67,68]. Thus, acrylonitrile, vinyl acetate, styrene, MMA, and the binary system of styrene and AN were grafted onto cellulose and cellulose derivatives. In... 

Photo-induced grafting onto wood cellulose with several vinyl monomers using phenyl acetophenone and benzophenone derivatives as photosensitizers has been reported [72]. A fast increase in grafting was observed for short irradiation times, whereas longer ones resulted in a decreased percent grafting. 

The mechanistic details of photo-induced grafting of styrene onto cellulose in the presence of mineral acids with methanol and dioxane as solvents was investigated... 

The theory of radiation-induced grafting has received extensive treatment. The direct effect of ionizing radiation in material is to produce active radical sites. A material s sensitivity to radiation ionization is reflected in its G value, which represents the number of radicals in a specific type (e.g., peroxy or allyl) produced in the material per 100 eV of energy absorbed. For example, the G value of poly(vinyl chloride) is 10-15, of PE is 6-8, and of polystyrene is 1.5-3. Regarding monomers, the G value of methyl methacrylate is 11.5, of acrylonitrile is 5.6, and of styrene is >0.69. 

There are a number of important factors that must be considered before applying gamma radiation-induced grafting. These factors include the radiation sensitivity of the polymer/monomer system, radiation dose and dose rate, type and concentration of inhibitor, type of solvent or diluent, and monomer concentration. The effect of such parameters on the grafting efficiency during mutual grafting is given below. 

Ionizing radiation is unselective and has its effect on the monomer, the polymer, the solvent, and any other substances present in the system. The radiation sensitivity of a substrate is measured in terms of its G value or free radical yield G(R). Since radiation-induced grafting proceeds by generation of free radicals on the polymer as well as on the monomer, the highest graft yield is obtained when the free radical yield for the polymer is much greater than that for the monomer. Hence, the free radical yield plays an important role in grafting process [85]. 

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