Biomedical subjects

F Ai

Publications and source records attributed to F Ai.

5 recordsLinked to original sources

PubMed2002

Grafting sulfobetaine monomer onto the segmented poly(ether-urethane) surface to improve hemocompatibility.

Polyurethanes are widely used as blood-contacting biomaterials, due to their good biocompatibility and mechanical properties. Nevertheless, their blood compatibility is still not adequate for more demanding applications. Surface modification is an effective way to improve the hemocompatibility for biomaterials. The purpose of the present study was to synthesize a novel nonthrombogenic biomaterial by modifying the surface of polyurethane. Ozonization was used to introduce active peroxide groups onto the segmented poly(ether-urethane) (SPEU) film surface and graft polymerization of N,N'-dimethyl (methacryloyloxyethyl) ammonium propanesulfonate (DMAPS), a sulfobetaine structure, onto the ozone-activated SPEU surface was conducted. The SPEU-g-PDMAPS film was characterized by ATR-FTIR, XPS, and contact angle measurements. ATR-FTIR and XPS confirmed the graft polymerization. The grafted film possessed a relatively hydrophilic surface, as revealed by contact angle measurement. The blood compatibility of the grafted films was evaluated by a platelet-rich plasma (PRP) adhesion study and scanning electron microscopy, using SPEU film as the reference. No platelet adhesion was observed for the grafted films incubated with PRP at 37 degrees C for 60 and 180 min. This new sulfobetaine structure grafted biomaterial might have potential for biomedical applications.

Betaine↗

PubMed2000

[Poly-static quantitative perimetry for detection of open angle glaucoma].

OBJECTIVE: To evaluate the sensitivity of poly-static quantitative perimetry for the detection of visual field defect in open angle glaucoma. METHODS: 48 patients (95 eyes) of open angle glaucoma were examined with poly-static quantitative perimetry [Friedmann visual field analyzer (FVFA)] and dynamic perimetry (tangent screen) respectively. RESULTS: 26 eyes showed small defect of visual field on tangent screen with 2/1,000 visual size, and 23 eyes (88%) showed the same defects checked with FVFA; visual field defects of early stage glaucoma were found in 26 eyes checked with FVFA, but only 16 eyes showed the same defects on tangent screen with 1/1,000 visual size; the visual field defects of glaucoma on tangent screen in 43 eyes were found larger when they were checked with FVFA. CONCLUSION: Comparing with dynamic perimetry, poly-static quantitative perimetry is more sensitive to detect visual field defect of early stage glaucoma.

Adult↗

PubMed1999

[Evaluating retinal nerve fiber layer by scanning laser ophthalmoscopy].

OBJECTIVE: To evaluate the efficiency of scanning laser ophthalmoscopy (SLO) on detecting retinal nerve fiber layer defects (RNFLD). METHODS: 95 eyes with primary open angle glaucoma, 37 ocular hypertension, 83 glaucomatous suspect and 34 normal eyes were investigated by SLO to evaluate the retinal nerve fiber layer (RNFL). Recording tapes of 68 eyes were re-investigated by two investigators for estimating the intra- and inter-observer agreement. RESULTS: The intra- and inter-observer agreement of the presence and types of RNFLD was fairly good (Kappa values were 0.66 - 0.76 and 0.59 - 0.65 respectively). The sensitivity and specificity in detecting RNFLD by SLO were 80.0% and 94.1% respectively. CONCLUSION: The evaluation of RNFL by SLO is a quick, accurate and safe method. It may be clinically useful in the diagnosis of glaucoma.

Glaucoma↗

PubMed1999

[Research of polymer coating in solid phase microextraction].

The solid phase microextraction (SPME) is a new extraction technique which has been developed rapidly in 1990s. It is a fast, simple, solventless and sensitive method for analyzing environmental samples. However, the solid phase materials of SPME are relatively limited. This paper presents the research work on a new type of solid phase, polymethylvinylsiloxane (PMVS), used in SPME. The phase with 1% vinyl content could be used in light curing. The PMVS solution was coated on the surface of silica fiber and was quickly cured by UV. Two fibers with 87 microns and 44 microns thick PMVS coatings were prepared. They were compared with commercial polymer coating SPME fibers through Headspace SPME Gas Chromatograph (HS-SPME-GC). The adsorption and desorption kinetics of PMVS were studied. The HS-SPME system was optimized and the differences between HS-SPME and HS were investigated as well. The results indicated that PMVS is efficient in extracting volatile and semi-volatile organic compounds and PMVS showed the high thermostability and easy-coating properties. The detection limit of SPME using 88 microns PMVS coating was about 1-5 micrograms/L.

English Abstract↗

PubMed1998

[Treatment of acute optic neuritis with high dose of prednisone].

OBJECTIVE: The benefit of glucocorticoid for the treatment of acute optic neuritis remains controversial. The efficacy of oral prednisone in 12 patients (14 eyes) with acute optic neuritis was reviewed. METHODS: The time of visual symptoms before treatment was 3-15 days. The visual acuities were worse than 0.1 in all patients, with positive relative afferent pupillary defect. Visual field defect and delay latency of P100 in pattern VEP were also found. The regimen of glucocorticoid therapy was oral prednisone, starting with 160 mg daily followed by reducing the dosage by 20 mg every three days until 40 mg per day was attained and then tapering the dosage at 70 mg every other day until stoppage of the drug. The treatment was 3-11 months and 9 patients were followed up more than one year. RESULTS: The visual acuities improved rapidly and stable. After 4 days, the visual acuity was 0.2 or better in 10 eyes. It was better than 0.6 in 12 eyes at 15 days. At 6 months, all had the visual acuity better than 0.7, with 85.7% equal or better than 1.0. CONCLUSIONS: The regimen of oral prednisone beginning with 160 mg followed by tapering for three months would be feasible. Pattern VEP was a sensitive and credible sign for evaluating the extent of demyelination.

Acute Disease↗